Lessepsian migration and parasitism: richness, prevalence and intensity of parasites in the invasive fish Sphyraena chrysotaenia compared to its native congener Sphyraena sphyraena in Tunisian coastal waters

New insights into two poorly known monogeneans (Platyhelminthes), gill parasites of the European barracuda Sphyraena sphyraena (Teleostei, Sphyraenidae) with notes on Chauhanea Ramalingam, 1953 and closely related genera

Two poorly known parasitic Platyhelminthes were collected from the gills of the European barracuda Sphyraena sphyraena in the western Mediterranean. Specimens of Chauhanea mediterranea Euzet & Trilles, 1960 and Rhinecotyle crepitacula Euzet & Trilles, 1960 (Polyopisthocotyla) are redescribed based on newly collected material. A careful examination of Ch. mediterranea revealed inaccuracies in previous interpretations of the female openings. The midventral opening, previously referred to as the 'vaginal opening' in Pseudochauhanea Yamaguti, 1965 and used to distinguish this genus from Chauhanea Ramalingam, 1953, is demonstrated to be the uterus, as confirmed by the presence of eggs in the thin-walled duct associated with this opening. The lateral position of the cirrus and vagina is also confirmed. Consequently, Pseudochauhanea is synonymized with Chauhanea, resulting in the following new combinations: Ch. elegans Fuentes-Zambrano, 1997 n. comb.; Ch. elongata Kritsky, Bilqees & Leiby, 1972 n. comb.; Ch. macrorchis Lin, Liu & Zhang in Zhang, Yang & Liu, 2001 n. comb.; Ch. mexicana Lamothe, 1967 n. comb.; Ch. sphyraenae Yamaguti, 1965 n. comb. A detailed investigation of the clamp sclerites of Ch. mediterranea indicates that both Chauhanea and Cotyloatlantica Bravo-Hollis, 1984 share the subdivision of the basal oblique sclerite, which is a continuation of the marginal sclerite in the anterior jaw, a key feature used to distinguish these genera. As a result, Cotyloatlantica is also synonymized with Chauhanea, and its species are transferred as follows: Ch. pretiosa (Bravo-Hollis, 1984) n. comb. The reinstatement of Ch. mediterranea Euzet & Trilles, 1960 as a valid name is supported, and an amended diagnosis of Chauhanea is provided. Additionally, R. crepitacula is accurately redescribed, with a new geographical locality record and an assessment of morphometrical and anatomical variations between Mediterranean and oceanic specimens.

EFSA Panel on Biological Hazards (BIOHAZ), Allende A, Alvarez‐Ordóñez A, Bortolaia V, Bover‐Cid S, De Cesare A, Dohmen W, Guillier L, Herman L, Jacxsens L, Nauta M, Mughini‐Gras L, Ottoson J, Peixe L, Perez‐Rodriguez F, Skandamis P, Suffredini E, Buchmann K, Levsen A, Mattiucci S, Mladineo I, Santos MJ, Guerra B, Goudjihounde SM, Hempen M, Bolton D. Re-evaluation of certain aspects of the EFSA Scientific Opinion of April 2010 on risk assessment of parasites in fishery products, based on new scientific data. Part 2

The objective of this opinion was to determine if any wild caught fish species, originating from specific fishing grounds and consumed in the EU/EFTA could be considered free of zoonotic parasites. In this Opinion the term 'fishery products' only refers to fresh finfish. As there are multiple fish species and numerous potential parasites, Anisakis sp. was used as an indicator of zoonotic parasites in marine areas. This parasite species is particularly suited as it is common in marine environments, capable of infecting multiple fish species and is the subject of the majority of published studies. On the rare occasion where Anisakis sp. data were not available, or all tests were negative, other parasites such as Contracaecum osculatum (s.l.) and/or Phocanema spp. were considered. In freshwater systems, all zoonotic parasites were investigated. Consumption, import and landing data were used to determine the most relevant fish species and, where possible, the source fishing areas were identified. The most commonly consumed wild caught fish species in the EU/EFTA include tuna, cod, Alaskan pollock, hake, herring, sardines, mackerel, trout and saithe. Although the majority of these fish are caught in the Atlantic Ocean, the Mediterranean and the Black Sea (37) as well as several areas in the Indian Ocean, imported fish may originate from any global fishing areas, with the exception of Antarctica. Based on the data, at least one zoonotic parasite has been reported in at least one fish species in each of the FAO marine fishing areas. Thus, due to relative low fish host specificity of the zoonotic parasites, the panel concluded that all wild caught fish species may be exposed to and infected with zoonotic parasites. The same applies to freshwater fishing areas, with many areas having multiple studies reporting the presence of zoonotic parasites in the wild caught fish species.

Parasites of pufferfish, Lagocephalus spp. and Torquigener flavimaculosus of the Israeli Mediterranean: A new case of Lessepsian endoparasites

With the opening of the Suez Canal as a link between the Red Sea and the Mediterranean Sea in 1869, the biogeographical event of the Lessepsian migration has been starting. Aided by beneficial conditions in the new habitat, almost 500 marine species have immigrated and often established themselves in the Mediterranean Sea, including several pufferfish species, with all of them extending their range and becoming important components of the local fauna. The parasitic fauna of these pufferfish has scarcely been examined in the Mediterranean Sea or in their native range, which provides the opportunity to study host-parasite interaction in a new habitat. The present study describes the parasitic fauna in four alien invasive pufferfish species (Lagocephalus guentheri, L. sceleratus, L. suezensis, and Torquigener flavimaculosus) of various sizes and ages on the Israeli Mediterranean coast. The parasite fauna of these species was diverse (Maculifer dayawanensis Digenea; Calliterarhynchus gracilis, Nybelinia africana and Tetraphyllidea larvae Cestoda; Hysterothylacium reliquens, Hysterothylacium sp. and Raphidascaris sp. Nematoda; Trachellobdella lubrica Hirudinea and Caligus fugu and Taeniacanthus lagocephali Copepoda) and consisted of mostly generalist species, most likely acquired in the new habitat, and specialist copepod ectoparasites, having co-invaded with the pufferfish. Additionally, the oioxenic opecoelid digenean Maculifer dayawanensis was found in two pufferfish species. The genus was previously only known from the Indo-Pacific Ocean, representing the eighth reported case of a Lessepsian endoparasite so far. Our results suggest a change in parasite fauna to native Mediterranean species in the pufferfish like previously reported in other Lessepsian migrant predatory fish species and a wider spread of co-invasion of fish endoparasites to the Mediterranean Sea than previously assumed. The study also provides several new host records and the first report for parasites in T. flavimaculosus.

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A comprehensive report of pufferfish parasites from Israeli Mediterranean Sea.

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Description of the parasitic fauna in four alien invasive pufferfish species on the Israeli Mediterranean coast.

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First report for parasites in T. flavimaculosus.

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Number of Lessepsian endoparasites is further increasing.

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First photographic record of Digenea from genus Maculifer Nicoll, 1915.

Under the radar: co-introduced monogeneans (Polyopisthocotylea: Gastrocotylinea) of the invasive fish Scomberomorus commerson in the Mediterranean Sea

The Levant Basin is in many ways the world's most invaded marine ecosystem owing to the existence of the man-made Suez Canal. The invasion of free-living organisms through this pathway is increasingly documented and monitored in the past two decades, and their ecological impact recognized. Nonetheless, while tremendous scientific effort is invested in documenting introduced fishes, co-introduction events of these fishes and their parasites have drawn relatively little interest. In our research, we examined the presence of gill parasites (Monogenea) on the invasive narrow barred Spanish mackerel Scomberomorus commerson which has been known in the Mediterranean Sea for 80 years. The gills of S. commerson supported numerous, relatively large monogeneans (Monogenea: Gastrocotylinea), reaching prevalence levels of 100% with a mean intensity of ~ 80 worms per host. Using an integrated molecular and morphological approach, four gastrocotylinean species were identified: Gotocotyla acanthura, Cathucotyle cathuaui, Pricea multae, and Pseudothoracocotyla ovalis. Two species, C. cathuaui and P. ovalis, are reported here for the first time from the Mediterranean. Sequences of the 28S rRNA gene of G. acanthura from native hosts, Pomatomus saltatrix and Trachinotus ovatus, differed from individuals collected from S. commerson by 1.8%. We therefore suggest that the taxonomic status and distribution of G. acanthura should be revisited, and we recommend an integrated approach as essential to accurately detect co-introductions.

Checklist of The Monogenea (Platyhelminthes) Parasitic in Tunisian Aquatic Vertebrates

153 species of monogeneans have been recorded in Tunisian aquatic vertebrates (89 hosts). A list of these species with hosts is presented. A comparison of the Monogenea diversity off the coast of Tunisia with other regions of the Mediterranean Sea and the world is provided. The number of parasites depends on the number of hosts examined and their diversity in the region. This list shows that Monopisthocotylea is the richest group. In addition, new records have been reported during a survey of the diversity of monogeneans fish in the southern coast of Tunisia (Gulf of Gabes) including: Benedenia monticellii (Parona and Perugia, 1895) Johnston, 1929, Lamellodiscus bidensEuzet, 1984, Lamellodiscus confusus Amine, Euzet & Kechemir-Issad, 2007, Lamellodiscus ergensi Euzet & Oliver, 1966, Lamellodiscus hiliiEuzet, 1984, Lamellodiscus imperviusEuzet, 1984, Lamellodiscus knoepffleri Oliver, 1969, Lamellodiscus theroni Amine, Euzet & Kechemir-Issad, 2007, Ligophorus acuminatus Euzet & Suriano, 1977, Ligophorus angustus Euzet & Suriano, 1977, Ligophorus heteronchus Euzet & Suriano, 1977, Ligophorus macrocolpos Euzet & Suriano, 1977, Ligophorus minimus Euzet & Suriano, 1977, Capsala maccallumi Price, 1939 and Pseudanthocotyloides heterocotyle (Van Beneden, 1871) Euzet & Prost, 1969.

Meridionalization as a Possible Resource for Fisheries: The Case Study of Caranx rhonchus Geoffroy Saint-Hilaire, 1817, in Southern Italian Waters

Climate change affects the shift range distribution of species, especially among mobile species, and this phenomenon can alter ecosystems and impacts human activities. Fishing is an anthropic activity that undergoes the effect not only of the introduction and increase of non-native species but also of native thermophilic ones. Some of these species can become a commercially exploitable resource. However, this information is often obscured by the negative effects these species can cause to the environment. We investigated how the thermophilic species Caranx rhonchus, neglected in Italy, could become a relevant resource. We studied the nutritional profile and the presence of heavy metal contamination and compared these traits with those of a similar common Mediterranean species, namely Trachurus trachurus. The proximate composition was determined following the AOAC procedure, while the fatty acid profile was determined by GC/MS, and the mineral component was obtained by mass spectrometer (ICP-MS). Caranx rhonchus is a nutritionally good species, although it is little consumed and exploited. Increasing the market supply with new commercially exploitable emerging species would benefit local communities and the environment. Therefore, it is necessary to investigate how a shift of the range caused by climate change can provide benefits within the human dimension.

Genera and Species of the Anisakidae Family and Their Geographical Distribution

Simple Summary

The parasites of the Anisakidae family infest mainly marine mammals; however, they have the ability to infest paratenic hosts such as mollusks, small crustaceans and fish. The consumption of meat from animals of aquatic origin favors the acquisition of the disease known as Anisakiasis or Anisakidosis, depending on the species of the infecting parasite. Currently, the identification of the members of this family is carried out through the use of molecular tests, which brings about the generation of new information. The purpose of this review was to identify the genus and species of the Anisakidae family by reviewing scientific papers that used molecular tests to confirm the genus and species. The adaptability of the Anisakidae family to multiple hosts and environmental conditions allows it to have a worldwide distribution. As it is a zoonotic agent and causes non-specific clinical symptoms, it is important to know about the different members of the Anisakidae family, as well as the hosts where they have been collected.

Abstract

Nematodes of the Anisakidae family have the ability to infest a wide variety of aquatic hosts during the development of their larval stages, mainly marine mammals, aquatic birds, such as pelicans, and freshwater fish, such crucian carp, these being the hosts where the life cycle is completed. The participation of intermediate hosts such as cephalopods, shrimp, crustaceans and marine fish, is an important part of this cycle. Due to morphological changes and updates to the genetic information of the different members of the family, the purpose of this review was to carry out a bibliographic search of the genus and species of the Anisakidae family identified by molecular tests, as well as the geographical area in which they were collected. The Anisakidae family is made up of eight different parasitic genera and 46 different species. Those of clinical importance to human health are highlighted: Anisakis pegreffi, A. simplexsensu stricto, Contracaecumosculatum, Pseudoterranova azarazi, P. cattani, P. decipiens and P. krabbei. The geographical distribution of these genera and species is located mainly in the European continent, Asia and South America, as well as in North and Central America and Australia. Based on the information collected from the Anisakidae family, it was determined that the geographical distribution is affected by different environmental factors, the host and the ability of the parasite itself to adapt. Its ability to adapt to the human organism has led to it being considered as a zoonotic agent. The disease in humans manifests nonspecifically, however the consumption of raw or semi-raw seafood is crucial information to link the presentation of the parasite with the disease. The use of morphological and molecular tests is of utmost importance for the correct diagnosis of the genus and species of the Anisakidae family.

The hidden companion of non-native fishes in north-east Atlantic waters

A tropicalization phenomenon of ichthyofauna has been described in the last decades in Galicia (north-eastern Atlantic), with increasing reports of tropical and subtropical fishes appearing northward this distribution range. A search for parasites was carried out in the digestive tract of two specimens first captured in Galician waters: the prickly puffer Ephippion guttifer (Tetraodontidae) and the African stripped grunt Parapristipoma octolineatum (Haemulidae). Examination of E. guttifer showed high intensity of nematodes, from three different genera: Cucullanus (Cucullanidae), Hysterothylacium (Raphidascaridae) and Anisakis (Anisakidae), with demonstrated pathogenicity to humans. Molecular identification allowed the identification of Anisakis pegreffii, already described in the area, and first reports for European waters of Cucullanus dodsworthi, Hysterothylacium reliquens and a new Hysterothylacium sp. P. octolineatum showed a far lower level of parasitization, with two Hysterothylacium larvae, genetically identified as Hysterothylacium deardorffoverstreetorum, also its first report in the eastern Atlantic. Thus, possible ecological impact of the occurrence of two non-native individual fishes in a new area could be remarkably higher if we see this issue through the lens of the parasitological perspective, as far as only two individual fish can harbour more of one hundred nematode parasites belonging to different species, most of them also new species for that area.