Structure of the large ribosomal subunit RNA of Phytophthora megasperma, and phylogeny of the oomycetes

New freshwater Ceratomyxa species, Ceratomyxa schwanefeldii n. sp. (Myxozoa: Ceratomyxidae) from the gall bladder of tinfoil barb, Barbonymus schwanefeldii (Cyprinidae, Cypriniformes) in Malaysia

Genus Ceratomyxa comprises coelozoic parasites of mainly marine and brackish water fish. This study describes a new Ceratomyxa species, Ceratomyxa schwanefeldii n. sp. which parasitizes the gall bladder of Barbonymus schwanefeldii collected from Sungai Tong in Setiu, Terengganu, Malaysia. The new species was described using morphological characteristics, and on nucleotide sequences of small subunit ribosomal DNA (SSU rDNA) and large subunit ribosomal DNA (LSU rDNA). Ceratomyxa schwanefeldii n. sp. exhibited vermiform shape plasmodia with slow undulatory motility, measuring 151.6 ± 86.0 (43.0-271.0) μm in length and 15.1 ± 4.8 (9.3-22.7) μm in width, with blunt poles at both ends. The mature spores were crescent-shaped, strongly arched in frontal view, with a sutural line between the two valves tapering to blunt ends. Formalin-fixed spores were 3.0 ± 0.4 (2.4-3.9) μm in length, 12.6 ± 1.2 (10.8-15.4) μm in thickness, with a concave posterior angle, 104.8° ± 10.2° (73.4-123.8). Two equal-sized spheroid polar capsules measured 1.5 ± 0.2 (1.2-1.8) μm in length and 1.3 ± 0.2 (0.9-1.7) μm in width. Phylogenetic analyses by Maximum likelihood and Bayesian Inference algorithms positioned C. schwanefeldii n. sp. as a sister species to Unicapsulocaudum mugilum and clustered within the clade of Amazonian freshwater Ceratomyxa species. The LSU rDNA phylogeny revealed that C. schwanefeldii n. sp. clusters within the marine Ceratomyxa clade and forms a sister relationship with C. leatherjacketi. This study represents the first description of a freshwater Ceratomyxa in Malaysia and the fourth recorded detection in the Asian region.

Two new myxozoan parasites, Myxobolus mayarum n. sp. and Kudoa mayarum n. sp., infecting the neotropical fish Mayan Cichlid, Mayaheros urophthalmus (Günther, 1862) in the Yucatán Peninsula, Mexico

The biodiversity of freshwater fishes is extensive in Mexico; however, knowledge of their associated myxozoan parasites is limited. This study aimed to recognize myxozoan parasites in the endemic fish Mayaheros urophthalmus. Two new species, Myxobolus mayarum n. sp. and Kudoa mayarum n. sp. were described from M. urophthalmus collected in the Celestún Coastal Lagoon and Baldiosera Freshwater Spring from the Yucatán Peninsula. Myxobolus mayarum n. sp. was found in 100 % of the examined fish, infecting the gills, kidney, pectoral fins, and spleen. The spores were round, 11.34 ± 0.67 μm length, 10.03 ± 0.44 μm width, and 7.22 ± 0.45 μm thickness. The polar capsules were pyriform and equal in size, 3.85 ± 0.29 μm length and 2.27 ± 0.20 μm width. The polar tubule 30.71 ± 2.10 μm long and coiled 5-6 times. Kudoa mayarum n. sp. was found in 30 % of fish, infecting the heart, oesophagus, and stomach. The spores were subspherical, 5.40 ± 0.40 μm length and 5.76 ± 0.37 μm width. The polar capsules were ellipsoidal and equal in size, 1.90 ± 0.27 μm length and 1.46 ± 0.20 μm width. The phylogenetic analyses based on the small and large subunits ribosomal DNA (18S rDNA and 28S rDNA) sequences demonstrated that these two species are distinct from other published myxozoans, providing evidence to support the description of two new species. This study constitutes the first record of myxozoans from the Yucatán Peninsula, contributing to increase the knowledge about the biodiversity of myxozoans in neotropical regions.

Genetic variability of Myxobolus nagaraensis (Bivalvulida: Myxobolidae) infecting freshwater gobies Rhinogobius Gill 1859 (Gobiiformes: Oxudercidae) from rivers in Japan

Myxobolus nagaraensis is a myxozoan parasite first reported in freshwater gobies (Rhinogobius spp.) from the Nagara River, Gifu Prefecture, Japan. Myxospores of M. nagaraensis form plasmodia in the visceral cavities of gobies, commonly presenting as distended abdomens. Although Rhinogobius is a common fish genus in Japan, details of M. nagaraensis, including genetic information, remain unknown. We compared the nucleotide sequences of the ribosomal RNA gene (rDNA) of M. nagaraensis from three different host species (R. fluviatilis, R. nagoyae, and R. similis) caught in three different rivers in Japan (Sakai, Sagami, and Kaname). The ITS region (ITS-1, 5.8S rDNA, and ITS-2) and large subunit (LSU) rDNA exhibited 49 and 55 variable sites, respectively. The highest nucleotide diversity was observed in the ITS region (0.00962), whereas that of the LSU rDNA was 0.00187. Differences in host species, rather than rivers, were a significant factor for genetic variation in both the ITS region (62.58%; P < 0.001) and LSU rDNA (55.22%; P < 0.01). Significant genetic variation was observed in M. nagaraensis from R. similis compared to R. fluviatilis (P < 0.001) or R. nagoyae (P < 0.001) from the same river. Such details are valuable for understanding parasite dispersal and its ecological impact on Rhinogobius hosts.

DNA barcoding of Anoplocephala perfoliata derived from a draft horse (Ban'ei horse) in Hokkaido, Japan

A two-year-old male Japanese draft horse (known as a "Ban'ei horse") excreted eight cestodes. Based on their morphological features, they were identified as Anoplocephala perfoliata. The partial mitochondrial cytochrome c oxidase subunit 1 (COI) sequences of the worms were nearly identical to A. perfoliata isolated from horses in Europe. The results of phylogenetic analyses of COI revealed that our samples and the European isolates formed the same clade, which was separate from Chinese and Australian isolates. Ban'ei horses were developed by crossbreeding draft horses imported from European countries in the 1900s. Our results suggest that A. perfoliata was transported to Hokkaido with horses from Europe. To our knowledge, this is the first report of A. perfoliata infection in a Japanese draft horse.

The gut microbiota-immune-brain axis in a wild vertebrate: dynamic interactions and health impacts

The gut microbiota-immune-brain axis is a feedback network which influences diverse physiological processes and plays a pivotal role in overall health and wellbeing. Although research in humans and laboratory mice has shed light into the associations and mechanisms governing this communication network, evidence of such interactions in wild, especially in young animals, is lacking. We therefore investigated these interactions during early development in a population of common buzzards (Buteo buteo) and their effects on individual condition. In a longitudinal study, we used a multi-marker approach to establish potential links between the bacterial and eukaryotic gut microbiota, a panel of immune assays and feather corticosterone measurements as a proxy for long-term stress. Using Bayesian structural equation modeling, we found no support for feedback between gut microbial diversity and immune or stress parameters. However, we did find strong relationships in the feedback network. Immunity was negatively correlated with corticosterone levels, and microbial diversity was positively associated with nestling body condition. Furthermore, corticosterone levels and eukaryotic microbiota diversity decreased with age while immune activity increased. The absence of conclusive support for the microbiota-immune-brain axis in common buzzard nestlings, coupled with the evidence for stress mediated immunosuppression, suggests a dominating role of stress-dominated maturation of the immune system during early development. Confounding factors inherent to wild systems and developing animals might override associations known from adult laboratory model subjects. The positive association between microbial diversity and body condition indicates the potential health benefits of possessing a diverse and stable microbiota.

Fatal Hymenolepis nana-associated visceral larva migrans in captive juvenile white-tailed antsangies (Brachytarsomysalbicauda)

White-tailed antsangies (Brachytarsomys albicauda) are Madagascan rodents uncommonly kept in captivity. Hymenolepis nana is a cestode with an unusual life cycle, incorporating direct, indirect and autoinfective stages. This case series represents the first reported outbreak of H. nana cestodiasis in white-tailed antsangies, summarizing macroscopic and histological findings in four cases. On post-mortem examination (PME), numerous cysticerci were detected consistently throughout the intestinal serosa, liver, mesenteric lymphatic vasculature and mesenteric lymph nodes. Pancreatic cysticerci were observed in one case. Adult tapeworms, larvae and eggs were found only in the small intestine, and faecal egg shedding was a feature. Histopathological examination identified adult, larval and encysted cestodes within the respective gross lesions, with pulmonary, pancreatic and splenic involvement detected in a single case. The cestodes sampled on PME were identified by polymerase chain reaction and DNA sequencing, with H. nana confirmed in all cases. Visceral larva migrans was consistent throughout all specimens, in contrast with the natural infections of standard rodent hosts, and may be considered a likely pathological feature of H. nana infection in white-tailed antsangies.

Phylogenetic relationships and systematics of tapeworms of the family Davaineidae (Cestoda, Cyclophyllidea), with emphasis on species in rodents

The present study aims at clarifying the poorly known phylogenetic relationships and systematics of cestodes of the family Davaineidae Braun, 1900 (Cyclophyllidea), primarily the genus Raillietina Fuhrmann, 1920 and of the subfamily Inermicapsiferinae (Anoplocephalidae) from mammals (mostly rodents, 31 new isolates) and birds (eight new isolates). Phylogenetic analyses are based on sequences of the large subunit ribosomal RNA gene (28S) and mitochondrial NADH dehydrogenase subunit 1 gene (nad1). The main phylogenetic pattern emerging from the present analysis is the presence of three independent lineages within the main clade of the subfamily Davaineinae, one of which is almost entirely confined to species from rodents and the other two show a mixture of species from birds and mammals. It is suggested that the major diversification of the main clade took place in birds, possibly in galliforms. The subsequent diversification included repeated host shifts from birds to mammals and to other birds, and from rodents to other mammals, showing that colonisation of new host lineages has been the main driver in the diversification of davaineine cestodes. It is also shown that all isolates of Inermicapsifer Janicki, 1910, mainly from rodents, form a monophyletic group positioned among Raillietina spp. in the "rodent lineage", indicating that the genus Inermicapsifer is a member of the family Davaineidae. This means that the subfamily Inermicapsiferinae and the family Inermicapsiferidae should be treated as synonyms of the Davaineidae, specifically the subfamily Davaineinae. Three additional genera generally included in the Inermicapsiferinae, i.e. Metacapsifer Spasskii, 1951, Pericapsifer Spasskii, 1951 and Thysanotaenia Beddard, 1911, are also assigned here to the Davaineidae (subfamily Davaineinae). Raillietina spp. were present in all three main lineages and appeared as multiple independent sublineages from bird and mammalian hosts, verifying the non-monophyly of the genus Raillietina and suggesting a presence of multiple new species and genera.

Integrative taxonomy of metazoan parasites of the bluntnose sixgill shark Hexanchus griseus (Bonnaterre, 1788) in the Mediterranean Sea, with the resurrection of Grillotia acanthoscolex Rees, 1944 (Cestoda: Trypanorhyncha)

Appropriate diagnoses of parasites of apex marine predators are crucial to understand their biodiversity, host specificity, biogeography, and life cycles. Such diagnoses are also informative of ecological and biological characteristics of both host and environment in which the hosts and their parasites live. We here (i) investigate the parasite fauna of a bluntnose sixgill shark Hexanchus griseus (Bonnaterre, 1788) obtained from the Gulf of Naples (Tyrrhenian Sea), (ii) characterize molecularly all its metazoan parasites, and (iii) resurrect and report the main morphological features and phylogenetic position of Grillotia acanthoscolex, a cestode species previously synonymized with Grillotia adenoplusia. A rich parasite fauna represented by eight different taxa was found, including two monogeneans (Protocotyle grisea and Protocotyle taschenbergi), one digenean (Otodistomum veliporum), four cestodes (Crossobothrium dohrnii, Clistobothrium sp., G. acanthoscolex, and G. adenoplusia), and one copepod (Protodactylina pamelae). Sequencing of these samples accounts for an important molecular baseline to widen the knowledge on the parasitic fauna of bluntnose sixgill sharks worldwide and to reconstruct their correct food chains. The bluntnose sixgill shark was found to be a definitive host for all endoparasites found here, confirming that it occupies an apex trophic level in the Mediterranean Sea. The taxa composition of the trophic parasite fauna confirms that the bluntnose sixgill shark mostly feeds on teleost fish species. However, the occurrence of two phillobothrid cestodes (C. dohrnii and Clistobothrium sp.) suggests that it also feeds on squids. Finally, we emphasize the importance of using integrative taxonomic approaches in the study of parasites from definitive and intermediate hosts to elucidate biology and ecology of taxa generally understudied in the Mediterranean Sea.

Early-life factors shaping the gut microbiota of Common buzzard nestlings

BACKGROUND

Exploring the dynamics of gut microbiome colonisation during early-life stages is important for understanding the potential impact of microbes on host development and fitness. Evidence from model organisms suggests a crucial early-life phase when shifts in gut microbiota can lead to immune dysregulation and reduced host condition. However, our understanding of gut microbiota colonisation in long-lived vertebrates, especially during early development, remains limited. We therefore used a wild population of common buzzard nestlings (Buteo buteo) to investigate connections between the early-life gut microbiota colonisation, environmental and host factors.

RESULTS

We targeted both bacterial and eukaryotic microbiota using the 16S and 28S rRNA genes. We sampled the individuals during early developmental stages in a longitudinal design. Our data revealed that age significantly affected microbial diversity and composition. Nest environment was a notable predictor of microbiota composition, with particularly eukaryotic communities differing between habitats occupied by the hosts. Nestling condition and infection with the blood parasite Leucocytozoon predicted microbial community composition.

CONCLUSION

Our findings emphasise the importance of studying microbiome dynamics to capture changes occurring during ontogeny. They highlight the role of microbial communities in reflecting host health and the importance of the nest environment for the developing nestling microbiome. Overall, this study contributes to understanding the complex interplay between microbial communities, host factors, and environmental variables, and sheds light on the ecological processes governing gut microbial colonisation during early-life stages.

Phylogeny of the cestode family Escherbothriidae (Cestoda: Rhinebothriidea) reveals unexpected patterns of association with skate hosts

The rhinebothriidean tapeworm family Escherbothriidae has recently been expanded to include the genus Ivanovcestus , species of which parasitise arhynchobatid skates. Similarities in morphology and host associations between Ivanovcestus and Semiorbiseptum - a genus yet to be assigned to one of the families in the order Rhinebothriidea - led us to explore the possibility that Semiorbiseptum might also belong in the Escherbothriidae. Morphological similarities with Scalithrium ivanovae , Scalithrium kirchneri and Rhinebothrium scobinae , all of which also parasitise arhynchobatid skates, raised questions regarding the generic placements of these species. In addition, new collections from the skate Sympterygia brevicaudata revealed two new species that morphologically resemble species of Ivanovcestus . A combination of morphological and molecular data were used to assess the generic placement of the newly discovered species and refine our understanding of the membership of the family Escherbothriidae. Sequence data for the D1-D3 region of the 28S rDNA gene were generated de novo for 14 specimens of 7 rhinebothriidean species and combined with comparable published data to represent all 6 families in the Rhinebothriidea in the analysis. The phylogenetic tree resulting from maximum likelihood analysis strongly supports the inclusion of the genus Semiorbiseptum in the family Escherbothriidae. Our work also suggests that the skate-hosted species previously assigned to Scalithrium and Rhinebothrium are also members of Semiorbiseptum and that Ivanovcestus is a junior synonym of Semiorbiseptum . Six species are transferred to Semiorbiseptum , bringing the total number of species in the genus to ten. The diagnosis of Semiorbiseptum is amended to accommodate the additional species. A second species in the previously monotypic type genus of the family, Escherbothrium , is described. The diagnosis of the Escherbothriidae is amended to include the new and transferred species. This study underscores the importance of integrating morphological and molecular data in bringing resolution to cestode systematics. We believe our findings provide a robust foundation for future research into the evolutionary history and host associations of cestodes within the order Rhinebothriidea and beyond. These also highlight the importance of expanding our understanding of skate-hosted cestodes. ZooBank: urn:lsid:zoobank.org:pub:8052AFCA-5FBD-4430-95F4-0E5E368DEA3D.

High species diversity of Phintella and Phintella-like spiders (Araneae: Salticidae) in Vietnam revealed by DNA-based species delimitation analyses

Salticidae (jumping spiders) usually exhibit pronounced sexual dimorphism in adult morphology, particularly body coloration and size and shape of the first legs. Consequently, the male and female from the same species might be erroneously assigned to different species or even different genera, which could generate synonymies in classification if only morphological data were used. Phintella is a species-rich genus of Salticidae, which currently exhibits 76 named species. However, the male-female counterpart is unknown for nearly half of the species. In this study, we used a molecular approach to delineate the species boundaries for Phintella and Phintella-like specimens collected in Vietnam, using morphological information as supporting data. We used three gene fragments (mitochondrial COI, 16S-ND1, and nuclear 28S) and biogeographical considerations for species delimitation. A total of 22 putative species were recognized: 18 species of the genus Phintella, one species of the genus Lechia (L. squamata), and three species of the genus Phinteloides. Eleven undescribed species were discovered, of which seven have a male-female combination, two species have only males, and two species have only females. The crown age of Phintella was estimated at the Serravallian stage of the Miocene after the increase of species number around 16 MYA. The crown ages of most putative species recognized in this study were estimated in the Pleistocene, and the divergence among sister species likely occurred from the mid-Miocene to the Pliocene. Our ancestral range reconstruction results showed that the diversification of our ingroup was governed by progressive dispersal events, i.e., Phintella and their related species in Vietnam diversified while expanding their range on the continent. Our results provide fundamental biodiversity data for a high-diversity genus in Vietnamese Phintella spiders.

A new freshwater Ceratomyxa species (Myxozoa: Ceratomyxidae) parasitizing a sciaenid fish from the Amazon Basin, Brazil

Myxozoans of Ceratomyxidae Doflein, 1899 are common coelozoic parasites of marine life, and are also found less frequently in freshwater fish. The present study describes Ceratomyxa ranunculiformis n. sp. as a new freshwater myxosporean species infecting the gall bladder of the Amazonian sciaenid Plagioscion squamosissimus. The new Ceratomyxa was described based on its host, myxospore morphology, ribosomal rDNA gene sequencing, parasite distribution, and phylogenetic analysis. Immature and mature plasmodia were tadpole-shaped or pyriform, and exhibited slow undulatory motility. The myxospores were elongated and crescent-shaped in the frontal view, with a sutural line between two valves, which had rounded ends. The measurements of the formalin-fixed myxospores were: average length 4.9 (4.0-6.6) μm, average thickness 37.6 (32.4-43.9) μm, average posterior angle 165° (154°-173°). Two ovoid polar capsules of equal size, average length 2.0 (1.4-3.0) μm and average width 1.9 (1.4-2.4) μm, were located adjacent to the suture and contained polar filaments with 2-3 coils. The integrated comparative analysis of the morphological characteristics and molecular analyses of the ribosomal rDNA genes supported the identification of a new species of coelozoic Ceratomyxa. Maximum likelihood analyses showed the new species clustering within a well-supported clade, together with all the other Amazonian freshwater ceratomyxids.

Dispersal and invasive stages of Urospora eugregarines (Apicomplexa) from brown bodies of a polychaete host

Urosporid eugregarines (Apicomplexa: Urosporidae) are unicellular eukaryotic parasites inhabiting the coelom or the intestine of marine invertebrates such as annelids, molluscs, nemerteans, and echinoderms. Despite the availability of published morphological and phylogenetical analyses of coelomic gregarines, their long-term survival in the host body cavity and dispersal routes into the marine environment remain unclear. Here, we focus on Urospora gametocysts and oocysts with sporozoites, which were found viable inside the so-called brown bodies floating in the body cavity of the polychaete Travisia forbesii. Brown bodies form as a result of host defence where coelomocytes encapsulate dead host cells and foreign objects including potential pathogens. We hypothesise the long-term persistence of Urospora eugregarines in brown bodies through evasion of the host immunity and outline possible pathways for their egress into the marine environment, applicable as dispersal routes for other parasites as well. Unique features revealed by detailed ultrastructural analysis of detected eugregarine stages include asynchronous sporogony, a massive sporozoite secretion apparatus, as well as the presence of free (possibly autoinfective) sporozoites within the gametocyst. The assignment to the genus Urospora and the complete identity with U. ovalis and U. travisiae were confirmed by analysing 18S rDNA sequences obtained from isolated gametocysts. The 18S rDNA phylogeny confirmed the affiliation of Urosporidae to Lecudinoidea and the grouping of all Urospora sequences with Difficilina from nemerteans and environmental sequences from the Artic region. We also enriched the Apicomplexa set by partial 28S rDNA sequences of two Urospora species enabling more complex phylogenetic analyses prospectively.

The Abyssal Parasitic Flatworm Fecampia cf. abyssicola: New Records, Anatomy, and Molecular Phylogeny, with a Discussion on Its Systematic Position

AbstractThe order Fecampiida, a group of parasitic turbellarians, has been poorly studied in terms of its species diversity, morphology, and ecology. Fecampiida is positioned within the monophyletic clade Adiaphanida, along with Tricladida and Prolecithophora, but their phylogenetic relationships are not well understood. Although the nervous and muscular systems of only two species in Fecampiida have been studied, recent research inferred morphological similarities between Fecampiida and Prolecithophora. In this study, we collected fecampiid cocoons and juveniles at depths of 1861-4438 m in Japanese waters. We identified the species on the basis of swimming juvenile specimens and by using histological and molecular methods, while we also examined its musculature and nervous system. Our study revealed a more complex nervous system than previously reported, with dorsal, lateral, and ventral pairs of longitudinal nerve cords connected through an anterior neuropile and posterior transverse commissures. While the nervous and muscular morphology suggested similarities with Prolecithophora, our phylogenetic analysis did not support a close relationship between Fecampiida and Prolecithophora.

Podarkeopsischinensis sp. nov. (Annelida, Hesionidae) from southeastern China

Podarkeopsischinensissp. nov. (Annelida, Hesionidae) is described based on specimens collected from the coast of southeast China. It is the first Podarkeopsis species described from the Indo-Pacific, although there are already nine valid Podarkeopsis species known from other parts of the world. This new species can be distinguished from the other Podarkeopsis species in having a palpostyle as long as the palpophore and double aciculae in both notopodia and neuropodia, and in bearing bifid furcate chaetae which have a smooth base on the shorter tine. A phylogenetic analysis based on the concatenated sequences of five gene fragments (COI, 16S rRNA, 18S rRNA, 28S rRNA, and histone H3) from 18 specimens of P.chinensissp. nov. showed that they formed a monophyletic clade that is sister to P.levifuscina. K2P genetic distances indicated that the four gene fragments (COI, 16S rRNA, 18S rRNA, and 28S rRNA) of P.chinensissp. nov. diverged from the corresponding sequences of the closest related species of Podarkeopsis in GenBank and BOLD Systems by 21.1-27.5%, 20.3-23.1%, 0.1-0.2%, and 2.1-3.2%. An identification key is provided for species in the genus Podarkeopsis.

Ortholinea nupchi n. sp. (Myxosporea: Ortholineidae) from the urinary bladder of the cultured olive flounder Paralichthys olivaceus, South Korea

A new myxosporean parasite, Ortholinea nupchi n. sp. (Myxozoa; Bivalvulida), was isolated from the urinary bladder of the olive flounder Paralichthys olivaceus cultured on Jeju Island, Korea. Mature spores were subspherical in the valvular and apical views and ellipsoidal in the sutural view. The spores measured 7.6 ± 0.5 μm in length, 6.7 ± 0.3 μm in thickness, and 7.3 ± 0.5 μm in width. Two pyriform polar capsules measured 3.2 ± 0.1 μm in length and 2.7 ± 0.1 μm in width and were located at the same level at the anterior half of the myxospores. The suture line was straight in the middle of the spores, and the surface ridges ranged between five and seven, forming an intricate pattern. The result of the 18S rDNA comparison showed ≤ 93.0% similarity with other Ortholinea species. The phylogenetic tree demonstrated that O. nupchi n. sp. was closest to O. auratae and clustered with oligochaete-infecting myxosporeans (OIM) having urinary system infection tropism. Based on the comparison of environmental and host factors in the phylogenetic groups of the OIM clade, we propose that the infection of O. nupchi n. sp. originated from marine oligochaetes.

Novelty and phylogenetic affinities of a new family of tapeworms (Cestoda: Rhinebothriidea) from endangered sawfish and guitarfish

The parasites of hosts of conservation concern are often poorly known. This is the case with the iconic group of elasmobranchs known as the sawfish of the genus Pristis, all four species of which are considered as Endangered or Critically Endangered by the International Union for Conservation of Nature (IUCN, Switzerland). Examination of cestodes from three species of sawfish (Pristis pristis, Pristis clavata, and Pristis zijsron) in Australia and one of their close relatives, the also critically endangered widenose guitarfish, Glaucostegus obtusus, in India collected over the past 25 years yielded four new species of tapeworms which are described herein. All four belong to the previously monotypic Mixobothrium; the diagnosis of the genus is revised to accommodate the new species. Among the new taxa is a species that had been included in previous molecular phylogenies but whose identity and affinities within the order Rhinebothriidea and thus also its familial placement were unclear. This species exhibits the morphological features of Mixobothrium and thus its identity is, at long last, revealed. Sequence data generated for the 28S rDNA gene for three of the new species, as well as an additional new but yet undescribed species from Pristis pectinata from Florida (USA), confirms the uniqueness of this group among the rhinebothriideans. The new family Mixobothriidae is established to house these taxa. The members of this family differ from all but one of the five other families of rhinebothriideans in lacking apical suckers on their bothridia. They are also distinctive in that their bothridia are divided into three distinct regions. The anterior and posterior regions have similar locular configurations to one another and differ from the locular configuration of the middle region. As a consequence, the bothridia are symmetrical along both their vertical and horizontal axes. We predict that a focus on species of guitarfish in the genus Glaucostegus will be the most productive approach for discovering additional diversity in this family of cestodes.

Parasite diversity and community structure of translocated Clarias gariepinus (Burchell) in South Africa: Testing co-introduction, parasite spillback and enemy release hypotheses

Clarias gariepinus (Burchell) is one of several freshwater fish species that have been translocated beyond its natural geographic range in South Africa. The present study investigated the parasitic communities of two translocated populations (one in the Riviersonderend River, Western Cape and the other from the Great Fish River, Eastern Cape) as well as its native source population from Gariep Dam, Free State. A total of nine, seven, and eight parasitic taxa were found to parasitise various organs of C. gariepinus from the three populations, respectively. The diversity and abundances of parasitic species in the two translocated populations were similar, but distinct community assemblages were observed. Parasite community composition from the Great Fish River was similar to that of the source population from Gariep Dam, whereas the parasitic community from C. gariepinus in the Riviersonderend River was distinct from that of Gariep Dam. This, together with the introduction history into the Western Cape, suggests that translocated C. gariepinus is sourced from various systems across South Africa, or that suitable intermediate hosts are present in the recipient ecosystems to sustain host-specific co-introduced parasitic taxa of C. gariepinus. In total, the resilience of 11 specialist parasite species of C. gariepinus is demonstrated in their persistence upon co-introduction into the two novel environments with their host, and support for the enemy release hypothesis is confirmed in the loss of known parasite taxa in translocated populations. The presence of the co-invasive fish lice Argulus japonicus Thiele, 1900 is reported from C. gariepinus in Gariep Dam and the Asian tapeworm Schyzocotyle acheilognathi (Yamaguti, 1934) was found from translocated C. gariepinus in the Riviersonderend River, Western Cape and lastly, a suspected case of parasite spillback from an unknown native host is reported.

Morphological and molecular reinvestigation of acanthoecid species III. - Kalathoeca cupula (Leadbeater, 1972) gen. et comb. nov. (=Stephanoeca cupula (Leadbeater) Thomsen, 1988)

Based on a further re-examination of loricate choanoflagellate species with detailed morphological (SEM/TEM) and molecular data of the SSU and LSU rRNA, the present study aims to give new insights for Stephanoeca cupula. In contrast to the original allocation within the family of tectiform reproducing species, morphological and molecular data of S. cupula sensu Leadbeater, 1972 points towards an affiliation within the nudiform reproducing family. Based on these new data, we here erect the nudiform genus Kalathoeca with its type species K. cupula gen. et comb. nov. Our data challenges morphological species assignments, as K. cupula shares its morphological lorica characteristics with tectiform reproducing species of Stephanoeca sensu stricto. Kalathoeca cupula is an interesting candidate for further investigating and understanding the evolutionary relationship of tectiform and nudiform reproducing species. Stephanoeca cupula sensu Thomsen, 1988 has been morphologically re-examined based on the renewed understanding of the morphological variability associated with S. cupula sensu Leadbeater, 1972 (=K. cupula), allowing us now to distribute the different morphological forms investigated within K. cupula and Pseudostephanoeca quasicupula.

Additional data on Spinitectus petterae (Nematoda: Rhabditida) from Clarias gariepinus (Siluriformes: Clariidae) in the Vaal River system: conserved morphology or high intraspecific genetic variability?

Two species of Spinitectus Fourment, 1884 have been recorded from southern Africa, namely Spinitectus polli Campana-Rouget, 1961 and Spinitectus petterae Boomker, 1993, both from the Limpopo River system. Spinitectus petterae was described from North African catfish, Clarias gariepinus (Burchell), whereas S. polli infects squeakers, Synodontis spp. During parasitological surveys in the Vaal River system (Orange River catchment), Spinitectus specimens were collected from C. gariepinus. These systems are adjacent but not connected. Therefore, this study aimed to identify the specimens collected using morphological and molecular techniques. The morphological study included light and scanning electron microscopy of whole specimens and excised spicules. Specimens were genetically characterised using 18S rDNA, 28S rDNA and cox1 mtDNA. Additionally, immature specimens of S. petterae were collected near the type locality. Morphological characteristics were most similar to S. petterae from C. gariepinus, whereas genetic data were dissimilar to all available data for the genus. Additional morphological characteristics noted for S. petterae in the present study were the details of the left and right spicule structure and the porous structures on the pseudolabia. Specimens from the Vaal River system differed from those originally described as S. petterae by additional spines posterior to the third ring, lacking caudal alae and variable total body and male oesophagus length. Based on 18S rDNA, haplotypes from the type locality varied only slightly from the study material, supporting the morphological identification. However, 28S rDNA and, more conspicuously, cox1 mtDNA displayed substantial variation between specimens from these localities, which needs further investigation. Haplotypes generated in the present study were highly dissimilar to those characterised for S. petterae from Tanzania and Egypt. Nevertheless, the nematodes collected from C. gariepinus in the Vaal River system are considered S. petterae. This study expands the geographical distribution and adds additional morphological and genetic information for S. petterae, contributing to the limited knowledge of African species of Spinitectus.

Biogeography, autecology, and phylogeny of Percolomonads based on newly described species

Percolomonads (Heterolobosea) are aquatic heterotrophic flagellates frequently found in saline waters up to hypersaline environments. We isolated and cultivated seven strains of percolomonad flagellates from marine waters and sediments as well as from a hypersaline inland lake in the Atacama Desert. Morphological characterizations, comprising light and scanning electron microscopy, revealed only slight differences between the strains mainly limited to the cell shape, length of flagella, and length of the ventral feeding groove. Phylogenetic analyses of the 18S and 28S rDNA genes showed the formation of three fully supported clades within the Percolomonadida: the Percolomonadidae, the Barbeliidae fam. nov. and the Lulaidae fam. nov. We describe two new families (Barbeliidae fam. nov., Lulaidae fam. nov.), a new genus (Nonamonas gen. nov.), and five new species (Percolomonas adaptabilis sp. nov., Lula levis sp. nov., Barbelia pacifica sp. nov., Nonamonas montiensis gen. et sp. nov., Nonamonas santamariensis gen. et sp. nov.). Salinity experiments showed that P. adaptabilis sp. nov. from the Atlantic was better adapted to high salinities than all other investigated strains. Moreover, comparisons of our cultivation-based approach with environmental sequencing studies showed that P. adaptabilis sp. nov. seems to be globally distributed in marine surface waters while other species seem to be more locally restricted.

Adding one more to the list: A new species of Eniochobothrium (Cestoda: Lecanicephalidea) from the Oman cownose ray in South Africa

A new species of Eniochobothrium Shipley and Hornell, 1906 was recovered from the Oman cownose ray (Rhinoptera jayakari Boulenger) from the body of water off the south-eastern coastline of the KwaZulu-Natal Province, South Africa. Eniochobothrium acostae n. sp. is described on morphological and molecular grounds. The new species is placed within Eniochobothrium (viz., Eniochobothrium gracile Shipley and Hornell, 1906, Eniochobothrium qatarense Al Kawari, Saoud and Wanas, 1994, Eniochobothrium euaxos Jensen, 2005) by possessing key generic characteristics such as the absence of a vagina, expansion of the anterior region of the strobila forming a trough and presence of a thick-walled cirrus sac. Molecular phylogenetic analyses of the partial 28S rRNA and mtCOI genes confirm the generic characterisation as the newly proposed species groups together with other members of the genus. Eniochobothrium acostae n. sp. currently represents the largest described species of the genus; it possesses slightly fewer testes compared to most congeners, given that this feature has been provided in the original description (e.g., E. euaxos and E. qatarense). The new species of Eniochobothrium is the fourth valid species described to date and the first species record from South African waters.

•

A new lecanicephalidean cestode is formally described based on morphological and molecular grounds.

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Molecular phylogenies of ribosomal (partial 28S rRNA) and mitochondrial (mtCOI) genes are provided.

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Molecular phylogenetic analyses placed the new species within the genus Eniochobothrium and support its validity.

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The new species is the fourth species of Eniochobothrium known to date and the first recorded from Southern Africa.

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Given the number of unassessed rhinopterid hosts, several species of Eniochobothrium may await scientific discovery.

Four new Phragmidium (Phragmidiaceae, Pucciniomycetes) species from Rosaceae plants in Guizhou Province of China

In this study, four new species of Phragmidium were proposed based on morphological and molecular characters. In morphology, Phragmidiumrosae-roxburghii sp. nov. was distinguished to related taxa by its unique square to diamond-shaped urediniospores; Ph.rubi-coreani sp. nov. differed from Ph.barclayi and Ph.cibanum because of teliospores with fewer cells and shorter pedicels; urediniospores of Ph.potentillae-freynianae sp. nov. were bigger than Ph.duchesneae-indicae; and Ph.rosae-laevigatae sp. nov. produced bigger urediniospores than Ph.jiangxiense. The phylogenetic analyses based on the combination of two loci (ITS and LSU) also supported our morphological conclusion. In the meantime, three previously known species were also described herein.

Allopodocotyle palmi sp. nov. and Prosorhynchus maternus Bray & Justine, 2006 (Digenea: Opecoelidae & Bucephalidae) from the Orange-Spotted Grouper Epinephelus coioides (Hamilton, 1822) off Bali, Indonesia, Described Using Modern Techniques

BACKGROUND

The most convincing species of Allopodocotyle Pritchard, 1966 (Digenea: Opecoelidae) are known overwhelmingly from groupers (Serranidae: Epinephelinae). Six species of Allopodocotyle have been reported, collectively, from species of Cromileptes Swainson, 1839, Epinephelus Bloch, 1793 and Plectropomus Oken, 1817. These are A. epinepheli (Yamaguti, 1942), A. heronensis Downie & Cribb, 2011, A. manteri (Saoud & Ramadan, 1984), A. mecopera (Manter, 1940), A. plectropomi (Manter, 1963) and A. serrani (Yamaguti, 1952). In addition, a not yet fully described and unnamed seventh species, morphologically and phylogenetically close to A. epinepheli, was isolated from the orange-spotted grouper Epinephelus coioides (Hamilton, 1822) off Bali, Indonesia in 2016. An eighth species, again from E. coioides off Bali is described herein.

METHODS

Morphological and phylogenetic analyses justify the recognition of A. palmi sp. nov., which is also genetically different from the as yet unnamed congener from the same host and locality. For the first time, 3D confocal laser scanning microscopy was applied to study and distinguish Digenea taxonomically. We introduce the 'Palm pattern', a new simplified way to visualise morphometric differences of related digenean taxa.

RESULTS

Allopodocotyle palmi sp. nov. is distinguished from its congeners that infect groupers by its elongate body with a size > 2.7 mm and diagonal testes. The ovary is located mainly, and the anterior testis completely, in the posterior half of the body; the uterine coils are in the fourth eighth of the body. The cirrus-sac is 0.75-1.4 (1.1) mm long, its posterior extremity is well separated from the anterior extent of the vitelline fields, just reaching the anterior border of uterine coils. In addition, Prosorhynchus maternus Bray & Justine, 2006 (Bucephalidae) was isolated from E. coioides, representing the first record in Indonesia and the third record for this fish species.

CONCLUSION

The biodiversity research in Indonesia is enhanced with a new species description based on modern and newly applied techniques.

Integrative Taxonomy Reveals Molicola uncinatus and Gymnorhynchus gigas (Cestoda: Trypanorhyncha) Coinfection in the Atlantic Pomfret Brama brama From the Mediterranean Sea, With Notes on the Phylogenetic Position of G. gigas Within the Family Gymnorhynchidae

The cestode family Gymnorhynchidae Dollfus, 1935 (Trypanorhyncha) comprises three genera and six valid species that are typically intestinal parasites of large pelagic sharks. Members of Gymnorhynchidae show a wide geographic distribution and represent a global sanitary concern because as larvae they infect the edible flesh of several commercially important fishes with some species having allergenic potential. Larval Gymnorhynchidae collected from the muscles of the Atlantic pomfret Brama brama from various localities in the Mediterranean Sea were identified and characterized by combining traditional morphology, scanning electronic microscopy, and molecular analyses using newly generated nuclear 18S and 28S rRNA sequences. Overall, 98 larvae were collected from 20 (100%) Atlantic pomfrets (intensity of infection: 4.9; range: 1–12). High-quality sequences were obtained for 54 larvae. Of these, 11 and 43 larvae were identified as Molicola uncinatus and Gymnorhynchus gigas, respectively. The phylogenetic analysis showed the existence of three main clades within Gymnorhynchidae. The first included species of G. gigas and M. uncinatus from the Mediterranean and Atlantic; the second and third major clades included an unidentified species of Molicola from the Indian Ocean and specimens of Gymnorhynchus isuri from the Mediterranean and Atlantic, respectively. Finally, Chimaerarhynchus rougetae was the basal and most diverging taxon. The phylogenetic analysis suggested that G. gigas is more closely related to the members of Molicola. We demonstrated the coinfection of M. uncinatus and G. gigas from all localities studied and extended the intermediate hosts and geographical range of M. uncinatus by including the Atlantic pomfret and the Tyrrhenian and Ionian Seas, respectively. The present results supported the previous proposal that G. gigas and Molicola species should be included in the same genus. Our study demonstrated the usefulness of the integrative taxonomy for the unequivocal recognition of larval trypanorhynch species, resolving the current difficulties in the taxonomy, and elucidating the poorly known ecological and biological aspects of members of Gymnorhynchidae.

Drivers of parasite communities in three sympatric benthic sharks in the Gulf of Naples (central Mediterranean Sea)

Sharks play a key role in the functioning of marine ecosystems and maintenance of trophic web balance, including life cycles of parasites co-occurring in their habitats. We investigated the structure of parasite communities of three sympatric shark species (Etmopterus spinax, Galeus melastomus, and Scyliorhinus canicula) and explored both the influence of host features in shaping the communities and their role as biological indicators of environment stability in the Gulf of Naples (central Mediterranean Sea), a geographical area characterized by strong anthropic pressure. Parasites found were all trophic transmitted helminths with a complex life cycle, except Lernaeopoda galei, that is a ecto-parasite copepod. Communities were all similarly impoverished with 4–5 component species and low values of species richness and diversity. Higher abundance of cestode larvae of the genus Grillotia was found in G. melastomus, although their dominance in all host species suggests that the three sharks have a similar role as intermediate/paratenic hosts in local food webs. Similarly, high abundance of Grillotia larvae could also suggest the occurrence of high abundance of largest top predators in the area. Host morphological (fork length in S. canicula and G. melastomus and body condition index in G. melastomus) and physiological (sex and gonadosomatic and hepatosomatic indices in S. canicula) variables were differently correlated to parasite community structures depending by host species. Potential reasons for the present impoverished parasite communities are discussed.

Kudoa hypoepicardialis and associated cardiac lesions in invasive red lionfish Pterois volitans in Grenada, West Indies

Invasive red lionfish Pterois volitans (Linnaeus, 1758) represent an ongoing ecological threat within temperate and tropical waters. Relatively little is known regarding the overall health of P. volitans and their potential for spreading pathogens in non-native regions. Lionfish collected from inshore reefs of Grenada, West Indies, in 2019 and 2021 were identified as P. volitans based on cytochrome c oxidase subunit 1 barcoding. Gross and microscopic examination of tissues revealed myxozoan plasmodia in the hearts of 24/76 (31.6%) lionfish by histopathology or wet mount cytology. Further histopathologic examination revealed severe granulomatous inflammation and myofiber necrosis associated with developing plasmodia and presporogonic life stages. Fresh myxospores were morphologically and molecularly consistent with Kudoa hypoepicardialis, being quadrate in apical view with 4 valves and 4 equal polar capsules. The spore body was 5.1-7.9 (mean: 6.0) µm long, 8.1-9.8 (8.7) µm wide, and 6.9-8.5 (7.7) µm thick. Polar capsules were 2.3-2.7 (2.5) µm long and 0.9-1.6 (1.3) µm wide. 18S small subunit rDNA sequences were 99.81-99.87% similar to sequence data from the original description of the species. Novel 28S large subunit rDNA and elongation factor 2 data, which did not match any previously reported species, were provided. This is the first account of a myxozoan parasite of P. volitans, a new host record and locality for K. hypoepicardialis, and one of few reports describing pathogen-associated lesions in invasive lionfish.

Morphological analysis of Rhynchospio aff. asiatica (Annelida: Spionidae) and comments on the phylogeny and reproduction of the family Spionidae

The genus Rhynchospio has fronto-lateral horns on prostomium, paired branchiae from chaetiger 2 to near the posterior end, capillary notochaetae only, and more than two pairs of pygidial cirri. Rhynchospio species are common in coastal soft bottom communities; nevertheless, many recorded Rhynchospio specimens around the world are currently undescribed. Here we described a Rhynchospio species based on specimens collected from Qingdao, China. Comparison with the reported DNA sequences of four gene markers (16S rRNA, 18S rRNA, 28S rRNA, and Histone H3) and brief morphological description of specimens collected from Jinhae Bay, South Korea, previously reported as Rhynchospio aff asiatica, indicated that they are conspecific. Morphologically, specimens of R. aff. asiatica from Qingdao are characterized by having neuropodial hooded hooks from chaetigers 14-17 (vs. 10-23 in R. asiatica) to near pygidial chaetigers, sperm from chaetiger 11 to 14 (vs. from chaetiger 11 to 21-22 in R. asiatica), oocytes from chaetigers 16-17 to 26-39 (vs. from 22-24 in R. asiatica), and 4-6 (vs. up to 6 in R. asiatica) pygidial cirri. Genetically, Rhynchospio aff. asiatica is most closely related to R. arenincola Hartman, 1936 from California, USA with the interspecific distances of 20.02% (16S rRNA), 4.50% (18S rRNA), 8.44% (28S rRNA), 2.74% (Histone H3), and 6.10% (concatenated sequences). Water flow across the dorsum created by ciliary beating of the branchiae and nototrochs, observed on live specimens, may help transport gametes from reproductive segments in anterior and middle parts to the posterior brooding segments. Phylogenetic trees based on concatenated sequences of four gene markers of 54 spioniform species in 25 genera revealed two clades, covering the two subfamilies Spioninae and Nerininae respectively. Two families (i.e., Poecilochaetidae and Trochochaetidae) in the order Spionida were clustered within Spionidae, supporting a morphology-based proposal that these families bearing a pair of prehensile, grooved palps should be grouped within a more broadly defined family Spionidae. Mapping morphological and reproductive characteristics to the phylogenetic trees indicated that the ancestor of spionids might lack branchiae, broadcast spawn thick-envelop oocytes and ect-aquasperm, and produce planktotrophic larvae.

A synergistic, global approach to revising the trypanorhynch tapeworm family Rhinoptericolidae (Trypanobatoida)

Since 2010, the trypanorhynch tapeworm family Rhinoptericolidae Carvajal & Campbell, 1975 has housed just two distinctive, monotypic genera (Rhinoptericola Carvajal & Campbell, 1975 and Nataliella Palm, 2010). However, global collections of tapeworms from sharks and rays over the last more than three decades brought to light the need for major revision of the family by suggesting a much greater species-level diversity for the nominal genus Rhinoptericola. Through synonymy and the description of new species, the number of species in the genus is increased from one to eight. A phylogenetic analysis of the D1-D3 gene region of 28S rRNA (28S), including seven of the now nine species of rhinoptericolids, and a broad sampling of the other Trypanobatoida is the first to recover a monophyletic Rhinoptericolidae. In addition to systematic revision, this study allowed for the first evaluation of the degree of intraspecific vs interspecific variation in 28S for adult trypanorhynchs across the various hosts and geographic localities from which they have been reported, suggesting a relatively consistent boundary for Rhinoptericola. It is further suggested that detailed scanning electron microscopy (SEM) images of both the basal and metabasal armatures greatly aid in the interpretation of hook arrangement and shape. A schematic to streamline determination of the tentacular surface presented in scanning electron micrographs and line drawings of trypanorhynchs is presented for species with both two and four bothria. In combination, these methodological refinements can now be used as a model to resolve issues of classification and non-monophyly within both major lineages of the Trypanorhyncha. As a result of the taxonomic work, Rhinoptericola megacantha Carvajal & Campbell, 1975 (previously only known from the American cownose ray from the Chesapeake Bay and the Ticon cownose ray from the Gulf of Mexico, Venezuela, and Brazil) is now known from an additional species of cownose ray and a species of stingray, and is revealed to have a transatlantic distribution. Data from SEM suggest a simpler interpretation of hook arrangement in the metabasal armature for Rhinoptercola and-in combination with 28S sequence data-support Shirleyrhynchus Beveridge & Campbell, 1988 (a former rhinoptericolid) as its junior synonym. The three species formerly assigned to Shirleyrhynchus are thus transferred to Rhinoptericola. Data from light microscopy on whole-mounted specimens and histological sections, SEM, and 28S showed the eutetrarhynchid Prochristianella jensenae Schaeffner & Beveridge, 2012b to be morphologically consistent with species of Rhinoptericola and it is thus transferred to the genus. The type series of P. jensenae was determined to be mixed, representing two distinct species which are here redescribed and described as new, respectively. Two additional novel species of Rhinoptericola are described from cownose rays from off Mozambique and the Gulf of California.

New data on Henneguya postexilis Minchew, 1977, a parasite of channel catfish Ictalurus punctatus, with notes on resolution of molecular markers for myxozoan phylogeny

Previous morphological and histological data are supplemented with molecular and ultrastructural data for a Henneguya sp. isolated from farm-raised channel catfish Ictalurus punctatus in Mississippi, USA. Myxospores were cryptic, encapsulated within a thin layer of epithelium in the gill lamellae with spore measurements consistent with the original description of Henneguya postexilis Minchew, 1977. Myxospores were 42.7-49.1 µm in total length with spore bodies 12.1-17.2 × 3.6-4.8 × 2.9-3 µm. Polar capsules were of unequal length, with the longer capsule being 4.4-6.7 × 1.1-1.6 µm and the shorter capsule being 4.4-6.4 × 1.1-1.6 µm. Polar tubules had 6-8 turns. Caudal processes were 25.7-38.1 µm in length. Spores were encapsulated in a thin layer of epithelium in the gill lamellae. Molecular data from the most commonly used markers for myxozoan identification and phylogeny, partial 18S small subunit ribosomal gene (SSU), partial 28S large subunit ribosomal gene (LSU), and elongation factor 2 (EF2) were generated for H. postexilis. Additionally, novel data for LSU and EF2 were generated for archived myxozoan specimens from farm-raised catfish (H. mississippiensis, H. ictaluri, H. exilis, H. adiposa, H. sutherlandi, H. bulbosus, Unicauda fimbrethilae), as well as archived specimens from wild fish (H. laseeae [from Pylodictis olivaris], Hennegoides flockae [from Aphredoderus sayanus], Myxobolus cloutmani [from Cycleptus elongatus]. These include the first EF2 sequence data for the genera Hennegoides and Unicauda. Phylogenetic analyses using these data placed H. postexilis in well supported clades with other ictalurid-infecting Henneguya species. Phylogenetic signal assessments on these analyses suggest that while SSU provided the greatest phylogenetic signal, LSU yielded comparable signal, supporting previous work implying this region may be underutilised in reconstructing myxobolid phylogenies.

Molecular Identification of Plerocercoids of Clistobothrium montaukensis (Cestoda: Phyllobothriidea) Parasitizing the King of Herrings Regalecus glesne

PURPOSE

Endo-parasites of the bathypelagic king of herrings Regalecus glesne and oarfish Regalecus russelii are only known from few specimens opportunistically examined. As a consequence, there are few records of parasites from either Regalecus species. We report plerocercoid larvae of phyllobothriidean cestodes parasitizing an adult R. glesne stranded in Bahía de La Paz, Baja California Sur, Mexico.

METHODS

Sixty-three plerocercoids were obtained from the intestine of R. glesne and characterized using morphological and molecular methods (nuclear 28S rDNA and mitochondrial cytochrome c oxidase I gene sequences).

RESULTS

Following the morphological diagnostic criteria of scolex and muscle bands in the strobila, plerocercoids specimens were preliminary assigned to the genus Clistobothrium. Mitochondrial and nuclear DNA sequences indicate these plerocercoids correspond to Clistobothrium montaukensis Ruhnke, 1993.

CONCLUSION

Regalecus glesne is a new host known for C. montaukensis and this report is a new geographical record of C. montaukensis parasitizing species of the genus Regalecus previously known only from California and Florida, USA.

Revision of the phylogeny of Placididea (Stramenopiles): Molecular and morphological diversity of novel placidid protists from extreme aquatic environments

Recent studies suggested that the diversity of microbial eukaryotes in hypersaline environments is widely underestimated. Placidids are a group of heterotrophic stramenopile flagellates that are frequently found in these environments, but up to now only very few species were isolated and fully described, mostly from marine or brackish water sites. In this study, we extend the known diversity of Placididea by three new genera (Allegra, Haloplacidia, and Placilonga) compromising nine new species, isolated from athalassic, mostly hypersaline environments (Allegra dunaii, Allegra atacamiensis, Allegra hypersalina, Haloplacidia cosmopolita, Suigetsumonas keniensis) and marine waters (Placilonga atlantica, Placidia azorensis, Placidia abyssalis, Wobblia pacifica) including a description of their morphology and molecular phylogeny. In total, 36 strains were comparatively analysed. Studies from athalassic waters revealed an especially high number of different genotypes. A multigene analysis based on a ten genes dataset revealed a clear separation into marine, athalassic and brackish water clades. Several representatives were found to cope with hypersaline conditions from 20 to 250 PSU, even up to 284 PSU, suggesting that they may form a halotolerant group.

Phylogenetic position of Acanthobothrium cleofanus (Cestoda: Onchoproteocephalidea) using molecular evidence

Despite the large number of species described to date for the onchoprotepcephalid genus Acanthobothrium (207), only 16 named species have a genetic sequence. With this background, specimens of adult cestodes of the stingray Hypanus longus were collected off San Blas, Nayarit, and onchoproteocephalid larvae in the carangid fish Trachinotus rhodopus from Puerto Ángel, Oaxaca, both located on the Pacific coast of Mexico. The objective of this work is to investigate the phylogenetic position of these adults and larvae using nuclear ribosomal markers (18S rDNA and 28S rDNA). Morphologically, adult specimens were identified as Acanthobothrium cleofanus; larvae were identified only to family level. The phylogenetic position of both taxa was investigated based on the information of two nuclear molecular markers analyzed under Parsimony (PA) and Bayesian Inference (BI) methods. The newly generated sequences of A. cleofanus from Nayarit are identical to the sequences of several samples of Acanthobothrium sp. collected in the Mexican Pacific, which sequence are available in GenBank; DNA sequences obtained from onchoproteocephalid larva clearly place this taxon within Acanthobothrium but representing an independent lineage. In the resulting phylogenetic trees, Uncibilocularis okei was found nested within Acanthobothrium with an unstable position depending on the optimality criteria, indicating the need for more molecular analyzes with a greater number of species of both genera prior to define its phylogenetic relationships.

A molecular and ecological study of Grillotia (Cestoda: Trypanorhyncha) larval infection in small to mid-sized benthonic sharks in the Gulf of Naples, Mediterranean Sea

AIM

Trypanorhyncha cestodes comprise a wide range of heteroxenous parasites infecting elasmobranchs as definitive hosts. Limited data exist on the larval infection of these cestodes and the role of intermediate and paratenic hosts in the life cycle of these parasites. We investigated the factors that determine the occurrence and the level of infection of Grillotia plerocerci in the skeletal muscles of various benthonic sharks and analyzed the parasites through an integrative taxonomic approach.

LOCATION

Mediterranean Sea.

METHODS

Sharks obtained as bycatch of commercial trawling activities (i.e., Etmopterus spinax, Galeus melastomus, and Scyliorhinus canicula) were used in this study. Data from a limited number of Dalatias licha and Scyliorhinus stellaris were also included. Grillotia plerocerci were molecularly characterized using the partial 28S large subunit rDNA. Boosted regression trees were used to model the relationship between the abundance of infection with both morphological and physiological predictors in each host.

RESULTS

Plerocerci of Grillotia were detected in all shark species except S. stellaris. Host species significantly differed in terms of parasite abundance, with the highest and lowest prevalence and abundance of infection detected in G. melastomus and E. spinax, respectively. The relative influence of the traits involved in explaining the parasite abundance was related to the host size in G. melastomus, while both morphology- and physiology-related traits explained the patterns observed in E. spinax and S. canicula. The 28S rDNA sequences shared an identity of ∼99.40% with a Grillotia species previously found in the Mediterranean Sea. At intraspecific level, two different genotypes were found. A first type was retrieved only from D. licha, whereas a second type was found in G. melastomus, E. spinax, and S. canicula.

MAIN CONCLUSIONS

Present results suggest that the two genotypes could be involved in different consumer-resource systems and confirm most of the examined shark species as transport hosts of Grillotia species for unknown larger top predators.

A NEW SPECIES OF MYXOBOLUS (CNIDARIA: MYXOSPOREA: MYXOBOLIDAE) FROM THE BLUE SUCKER, CYCLEPTUS ELONGATUS (LESUEUR) (CYPRINIFORMES: CATOSTOMIDAE: CYCLEPTINAE), FROM ARKANSAS

During 9-10 February 2018 and 21-22 February 2020, 7 adult Blue Suckers, Cycleptus elongatus, were collected by hoop nets from the Red River, Little River County (n = 3), and the Black River, Lawrence County (n = 4), Arkansas, and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. All 7 (100%) were infected with an unknown species of gill-infecting Myxobolus sp. Twenty formalin-fixed plasmodia (cysts) of Myxobolus cloutmani n. sp. were elliptoidal, 407 μm long × 270 μm wide. Formalin-fixed myxospores were orbicular to broadly elliptoidal, 8.7 μm long × 7.8 μm wide. Two polar capsules were pyriform and subequal in size, extending over halfway in the myxospore. The larger polar capsule was 5.5 μm long × 3.1 μm wide, while the shorter was 5.1 × 2.9 μm. A coiled polar filament possessed 5 or 6 coils. The myxospore was 3.7 μm thick in sutural view, with a distinct sutural ridge. Qualitative and quantitative morphological data were from formalin-fixed as well as ethanol-preserved spores, while molecular data consisted of a 2,010 base pair sequence of the partial 18S ribosomal RNA gene and a 2,502 base pair sequence of the partial 28S ribosomal RNA gene. Phylogenetic analysis grouped M. cloutmani n. sp. with the other catostomid-infecting myxobolids. This is the first myxozoan reported from C. elongatus.

A revision of the Rhoptrobothriidae (Cestoda: Tetraphyllidea)

The Rhoptrobothriidae are one of the more enigmatic families of cestodes of elasmobranchs. Opinions on the taxonomic status of the familys three original genera (i.e., Myzophyllobothrium, Rhoptrobothrium, and Myzocephalus) have varied over the 115 years since they were erected. Some authors have considered all three valid, others have considered Rhoptrobothrium to be a synonym of Myzopyllobothrium or a genus inquirendum, yet others have considered Myzocephalus to be a synonym of the phyllobothriid genus Thysanocephalum. All three genera were established for specimens collected from eagle rays off Sri Lanka. The erection of Mixophyllobothrium for two specimens from a cowtail stingray off India three decades ago added additional confusion to the situation, with some authors considering it valid and others a synonym of Myzocephalus. These disagreements stem largely from differences in interpretation of the complex morphology of the scolex of members of these genera. Furthermore, with the exception of Rhoptrobothrium comprising four species, each genus is monotypic. All but Rhoptrobothrium has not been considered in detail for nearly a century, largely because of a lack of available material. The taxonomic status of these genera is assessed here based on light and scanning electron microscopy, and molecular data generated from new material collected from eagle rays off Indonesian and Malaysian Borneo, Japan, Sri Lanka, and Viet Nam. Morphological work indicates that the genera differ largely only in the degree of folding of the four remi that extend from the cephalic peduncle. A molecular phylogeny based on sequence data for the D1D3 region of the 28S rRNA gene, which include new data for eight specimens of four species, indicates that Myzophyllobothrium, Myzocephalus, and Rhoptrobothrium are not mutually monophyletic. The latter two genera and Mixophyllobothrium are considered synonyms of Myzophyllobothrium and five species are transferred to that genus. Myzophyllobothrium okamuri n. comb. is considered a species inquirendum. Myzophyllobothrium nagasawai n. sp. is described from Aetobatus narutobiei off Japan. Myzophyllobothrium narinari n. comb. is re-described based on newly collected cestodes from the type host and locality (i.e., Aetobatus ocellatus off Sri Lanka). Despite consisting of only a single genus, the family status of the group is retained in recognition of the unusual configuration of the scolex, which bears four biloculate bothridia and four remi extending from the cephalic peduncle. The ordinal placement of the family remains uncertain, but affinities with the Phyllobothriidea, rather than Tetraphyllidea are considered.

Phylogeny of the supertribe Nebriitae (Coleoptera, Carabidae) based on analyses of DNA sequence data

The phylogeny of the carabid beetle supertribe Nebriitae is inferred from analyses of DNA sequence data from eight gene fragments including one nuclear ribosomal gene (28S), four nuclear-protein coding genes (CAD, topoisomerase 1, PEPCK, and wingless), and three mitochondrial gene fragments (16S + tRNA-Leu + ND1, COI ("barcode" region) and COI ("Pat/Jer" region)). Our taxon sample included 264 exemplars representing 241 species and subspecies (25% of the known nebriite fauna), 39 of 41 currently accepted genera and subgenera (all except Notiokasis and Archileistobrius), and eight outgroup taxa. Separate maximum likelihood (ML) analyses of individual genes, combined ML analyses of nuclear, nuclear protein-coding, and mitochondrial genes, and combined ML and Bayesian analyses of the eight-gene-fragment matrix resulted in a well-resolved phylogeny of the supertribe, with most nodes in the tree strongly supported. Within Nebriitae, 167 internal nodes of the tree (out of the maximum possible 255) are supported by maximum-likelihood bootstrap values of 90% or more. The tribes Notiophilini, Opisthiini, Pelophilini, and Nebriini are well supported as monophyletic but relationships among these are not well resolved. Nippononebria is a distinct genus more closely related to Leistus than Nebria. Archastes, Oreonebria, Spelaeonebria, and Eurynebria, previously treated as distinct genera by some authors, are all nested within a monophyletic genus Nebria. Within Nebria, four major clades are recognized: (1) the Oreonebria Series, including eight subgenera arrayed in two subgeneric complexes (the Eonebria and Oreonebria Complexes); (2) the Nebriola Series, including only subgenus Nebriola; (3) the Nebria Series, including ten subgenera arrayed in two subgeneric complexes, the Boreonebria and Nebria Complexes, with the latter further subdivided into three subgeneric subcomplexes (the Nebria, Epinebriola, and Eunebria Subcomplexes)); and (4) the Catonebria Series, including seven subgenera arrayed in two subgeneric complexes (the Reductonebria and Catonebria Complexes). A strong concordance of biogeography with the inferred phylogeny is noted and some evident vicariance patterns are highlighted. A revised classification, mainly within the Nebriini, is proposed to reflect the inferred phylogeny. Three genus-group taxa (Nippononebria, Vancouveria and Archastes) are given revised status and seven are recognized as new synonymies (Nebriorites Jeannel, 1941 and Marggia Huber, 2014 = Oreonebria Daniel, 1903; Pseudonebriola Ledoux & Roux, 1989 = Boreonebria Jeannel, 1937; Patrobonebria Bänninger, 1923, Paranebria Jeannel, 1937 and Barbonebriola Huber & Schmidt, 2017 = Epinebriola Daniel & Daniel, 1904; and Asionebria Shilenkov, 1982 = Psilonebria Andrewes, 1923). Six new subgenera are proposed and described for newly recognized clades: Parepinebriola Kavanaugh subgen. nov. (type species: Nebria delicata Huber & Schmidt, 2017), Insulanebria Kavanaugh subgen. nov. (type species: Nebria carbonaria Eschscholtz, 1829), Erwinebria Kavanaugh subgen. nov. (type species Nebria sahlbergii Fischer von Waldheim, 1828), Nivalonebria Kavanaugh subgen. nov. (type species: Nebria paradisi Darlington, 1931), Neaptenonebria Kavanaugh subgen. nov. (type species: Nebria ovipennis LeConte, 1878), and Palaptenonebria Kavanaugh subgen. nov. (type species: Nebria mellyi Gebler, 1847). Future efforts to better understand relationships within the supertribe should aim to expand the taxon sampling of DNA sequence data, particularly within subgenera Leistus and Evanoleistus of genus Leistus and the Nebria Complex of genus Nebria.

Extended divergence estimates and species descriptions of new craspedid choanoflagellates from the Atacama Desert, Northern Chile

In contrast to previous perspectives, hypersaline environments have been proven to harbour a variety of potentially highly adapted microorganisms, in particular unicellular eukaryotes. The isolated, hypersaline waterbodies in the Atacama Desert, Northern Chile are exposed to high UV radiation and deposition of toxic heavy metals, making them of great interest regarding studies on speciation and evolutionary processes. In the past two years, among a variety of other protist species, five new species of heterotrophic choanoflagellates were described and analysed from this area, showing an adaptation to a broad range of salinities. Morphological data alone does not allow for species delineation within craspedid species, additional molecular data is essential for modern taxonomy. In addition, molecular clock analyses pointed towards a strong selection force of the extreme environmental conditions. Within this study, we describe three additional craspedid choanoflagellate species, isolated from different aquatic environments. Phylogenetic analyses show two distinct clades of choanoflagellates from the Atacama, suggesting two independent invasions of at least two ancestral marine species, and, as indicated by our new data, a possible dispersal by Andean aquifers. The extended molecular clock analysis based on transcriptomic data of choanoflagellate strains from the Salar de Llamará, a hypersaline basin within the Central Depression of the Atacama Desert, reflects colonisation and divergence events which correspond to geological data of the paleohydrology.

High and specific diversity of protists in the deep-sea basins dominated by diplonemids, kinetoplastids, ciliates and foraminiferans

Heterotrophic protists (unicellular eukaryotes) form a major link from bacteria and algae to higher trophic levels in the sunlit ocean. Their role on the deep seafloor, however, is only fragmentarily understood, despite their potential key function for global carbon cycling. Using the approach of combined DNA metabarcoding and cultivation-based surveys of 11 deep-sea regions, we show that protist communities, mostly overlooked in current deep-sea foodweb models, are highly specific, locally diverse and have little overlap to pelagic communities. Besides traditionally considered foraminiferans, tiny protists including diplonemids, kinetoplastids and ciliates were genetically highly diverse considerably exceeding the diversity of metazoans. Deep-sea protists, including many parasitic species, represent thus one of the most diverse biodiversity compartments of the Earth system, forming an essential link to metazoans.

The pico-sized Mamiellophyceae and a novel Bathycoccus clade from the summer plankton of Russian Arctic Seas and adjacent waters

Global climate changes and anthropogenic activity greatly impact Arctic marine biodiversity including phytoplankton which contribute greatly to atmospheric oxygen production. Thus the study of microalgae has rising topicality. Class Mamiellophyceae is an important component of phototrophic picoplankton. To gain more knowledge about Mamiellophyceae distribution and diversity special studies were performed in such remote areas as the Russian Arctic seas. A metabarcoding of pico-sized Mamiellophyceae was undertaken by high-throughput sequencing of the 18S rRNA gene sequence V4 region from samples collected in July-September 2017 in the Barents, Kara and Laptev seas, and in the adjacent waters of the Norwegian Sea. Our study is the first to show that Mamiellophyceae among the summer picoplankton of Russian Arctic seas are diverse and represented by 16 algae species/phylotypes. We discovered a new candidate species of Bathycoccus assigned to a new Bathycoccus clade A-uncultured Bathycoccus Kara 2017. It was found that several Micromonas species can co-exist, with Micromonas polaris dominating north of 72°N. The presence of Ostreococcus tauri, Ostreococcus lucimarinus and Ostreococcus mediterraneus at high latitudes beyond 65°N was documented for the first time, similar to findings for some other taxa. Our results will be important for obtaining a global view of Mamiellophyceae community dynamics.

A new species of Grillotia Guiart, 1927 (Cestoda: Trypanorhyncha) from the spotted skate, Raja straeleni Poll, in South Africa

A new species of Grillotia Guiart, 1927 was recovered from the spotted skate (Raja straeleni Poll) from the south coast of the Western Cape, South Africa. Grillotia sasciae n. sp. is described based on morphological and molecular data. This species most closely resembles species in the subgenus Grillotia (viz., Grillotia borealis Keeney and Campbell, 2001, Grillotia brayi Beveridge and Campbell, 2007, Grillotia dollfusi Carvajal, 1971, Grillotia erinaceus Dollfus, 1969, Grillotia musculara Hart, 1936 and Grillotia patagonica Menoret and Ivanov, 2012) in having four hooks per principal row and intercalary hook rows in the metabasal region of the tentacular armature, a band of hooks on the external tentacular surface, numerous proglottids, and the presence of an uterine pore, a hermaphroditic sac, and internal and external seminal vesicles. The molecular phylogenetic analysis of the partial 28S rDNA gene, confirms the morphological data as it also groups Grillotia sasciae n. sp. within the G. erinaceus species complex. Grillotia sasciae n. sp. is distinctive among all other valid species in the complex by having two enlarged, uncinate hooks in the basal armature, of a different shape and size from the remaining hooks 1(1') in the metabasal armature. In addition, the retractor muscle of Grillotia sasciae n. sp. attaches at the posterior region of the tentacular bulb rather than the middle portion, continuing posteriorly as seen in most congeners (viz., G. erinaceus, G. borealis, G. brayi, G. musculara and G. pantagonica). The new species is the seventh species within the subgenus Grillotia and the first record of a species of Grillotia from southern African waters.

Fins infestation induced by Myxobolus xiantaoensis in yellow catfish Tachysurus fulvidraco Richardson, 1846: Some pathophysiological and molecular insights

The myxozoan parasite Myxobolus xiantaoensis is a fin pathogen of commercially important yellow catfish Tachysurus fulvidraco Richardson, 1846, in the freshwater ponds of China. In the present work, four geographical isolates of M. xiantaoensis were sampled from the fins of yellow catfish. It was found that the spores of four isolates exhibited few markable differences in morphometrics. The small subunit ribosomal DNA (SSU rDNA) sequences of four isolates were conspecific to the SSU rDNA sequence of M. xiantaoensis. No genetic level variation was observed, even in the characteristically more variable internal transcribed spacer (ITS) region. This absence of variability suggests high gene flow as a result of panmixia in the parasitic populations. ITS phylogeny placed four isolates of M. xiantaoensis in a clade together with myxozoans species infecting Siluriformes. The M. xiantaoensis infection inflicted severe hemorrhages on epidermis of ray-fins, which grew into inflammatory epithelial hyperplasia and lytic cartilage signs. The histochemical analysis of infected fins biopsies is characterized by damage of collagen components of cartilage, resulting in weakness, breaks, and missing fin rays. These tissue sections also had a remarkable inflammatory response around the fin cartilage, with the absence of mature spores and chondrocytes. These results indicate that the fin cartilage damage appeared before the development of tissue inflammation and the parasitic infestation of the fins. The present four geographical isolates of M. xiantaoensis were identified by a holistic approach of species characterization based on biological, morphological, and molecular evidence. These four isolates showed some morphological and genetic variations but within the intraspecific range.

Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

Background

Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, species richness and the molecular diversity and phylogeny of larval stages of strigeid trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. Here, we report our use of recently obtained sequences of several molecular markers to analyse some aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts.

Methods

From April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, the second internal transcribed spacer region (ITS2) region and the cytochrome c oxidase (COI) fragment.

Results

Among investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 individuals. The taxonomic generic affiliation of metacercariae derived from the leeches revealed the occurrence of two strigeid genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Taking currently available molecular data and our results into consideration, recently sequenced tetracotyle of Australapatemon represents most probably Au. minor; however, unclear phylogenetic relationships between Au. burti and Au. minor reduce the reliability of this conclusion. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host.

Conclusions

The results of this study suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius, with potential serious evolutionary consequences for a wide range of host–parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurus raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.

Wenyonia gracilis sp. n. (Cestoda: Caryophyllidea) from Synodontis zambezensis (Siluriformes: Mochokidae): the first native caryophyllidean tapeworm from southern Africa

Parasitological examination of freshwater fishes of the Phongolo River in north-eastern KwaZulu-Natal, South Africa resulted in the discovery and morphological and molecular characterisation of a new species of Wenyonia Woodland, 1923 (Cestoda: Caryophyllidea). The new species from the plain squeaker, Synodontis zambezensis Peters (Siluriformes: Mochokidae), is morphologically most similar to Wenyonia acuminata Woodland, 1923, a species reported from three species of Synodontis in north-eastern, western and central Africa (Sudan, Nigeria, Democratic Republic of the Congo). Both these species are markedly different from congeners by having a nematoform body and a digitiform scolex. Wenyonia gracilis sp. n. differs from W. acuminata in its general body size, length and width of main body regions (testicular and uterine regions), a posterior extension of the testes into the uterine region, numerous postovarian vitelline follicles filling the entire medulla, eggs c. 1/3 larger in size, and a scolex with an apical introvert but devoid of longitudinal furrows and a well-defined base. Wenyonia gracilis is the seventh species in the genus and the first autochthonous caryophyllidean ever reported and described from southern Africa (south of the Zambezi River).

New Parasite Records for the Sunfish Mola mola in the Mediterranean Sea and Their Potential Use as Biological Tags for Long-Distance Host Migration

Studies describing the parasite fauna of sunfish species from the Mediterranean Sea are to date limited, despite information gained through parasitological examination may reveal unknown ecological and biological aspects of both hosts and parasites. Moreover, recent molecular studies on sunfish taxonomy revealed the presence of two species belonging to the genus Mola in the Mediterranean basin, namely M. mola and M. alexandrini. These two fish taxa have long been synonymized or confused among them, which implies that the majority of the studies carried out so far reported the parasites infecting both species under a single host species, generally referred to as M. mola. We hereby investigated the parasite fauna of a 43 cm long M. mola specimen from the Mediterranean Sea, whose identification was confirmed by molecular tool, and provided the first evidence of the occurrence of the nematode Anisakis simplex (s.s.) and of the cestode Gymnorhynchus isuri in Mola species anywhere. The use of helminth species as biological tags for the sunfish is also discussed.

Species diversity, taxonomy, and phylogeny of Gymnosporangium in China

Gymnosporangium is a group of plant fungal pathogens that cause rust diseases on many economically important fruit trees. Most Gymnosporangium are heteroecious and demicyclic, producing four morphologically diverse spore stages on two taxonomically unrelated host plants, the Cupressaceae and Rosaceae. The complex life cycle and heteroecism make it difficult to investigate the species within Gymnosporangium. To determine the taxonomy, phylogeny, and species diversity of Gymnosporangium in China, a large collection of 672 specimens were analyzed using a combination of morphological observations and phylogenetic analyses. In total, 27 Gymnosporangium species from China are documented here, including 22 known species, one new combination, one new record, and three new species. The study also documents a novel aeciospore surface structure with an irregular surface that is described here as "surfy."