Freshwater fishes of Iraq: a revised and updated annotated checklist2023

The current status of the freshwater fishes of Iraq is revised, and an updated checklist is presented. The confirmed freshwater fishes of Iraq comprise 98 species belonging to 16 orders, 28 families, and 56 genera. Among these, 21 species (21.4%) are alien, and three species (3.0%) are considered endemic to Iraq. The orders with the largest numbers of species in the ichthyofauna of Iraq are Cypriniformes (57 species), followed by Siluriformes (12 species), Mugiliformes and Cyprinodontiformes (six species in each), Acanthuriformes and Cichliformes (three species in each), Centrarchiformes and Gobiiformes (two species in each), and the others represent only one species. At the family level, the Cyprinidae have the greatest number of species (28; 28.3% of the total species), followed by Nemacheilidae (16 species), Leuciscidae (eight species), Mugilidae (six species), Sisoridae (five species), and Xenocyprididae (four species in each). A total of 20 species that have been previously reported from Iraq have been excluded from the checklist. According to IUCN Red List criteria, among 77 naturally distributed species (alien species not included), 10 species (13.0%) are categorized as threatened extinctions, with three (3.9%) as CR, one (1.3%) as EN, and six (7.8%) as VU. A total of 38 taxa were assessed (49.4%) as LC, 27 species were not assigned NE (35.1%), and two species (2.0%) were classified as DD, i.e., with insufficient knowledge.

Fish Species Composition, Distribution and Community Structure in Relation to Environmental Variation in a Semi-Arid Mountainous River Basin, Iran

We analyzed spatial variation in fish species richness and community composition in the Karun River basin, Iran. Knowledge about fish diversity in the basin is incomplete and varies widely along spatial and temporal scales: The Karun is the longest river in Iran (950 km) with the largest drainage area (about 67,000 km²). Fish samples were collected from 54 sites from July through August 2019 using a backpack electro-fisher. Physico-chemical and habitat parameter data collected at each site included pH, conductivity (μS/cm), dissolved oxygen (mg/L), water temperature (°C), turbidity (NTU), stream width (m), stream depth (m), water velocity (m/s) and elevation (m). In total, 37 species were collected (5241 individuals weighing 110.67 kg). The species collected represented 12 families and 27 genera. A total of 13 endemic species (35.14%), 16 native species (43.24%), and eight non-native species (21.62%) were recorded. Diversity indices were calculated and used to measure the spatial variation in community composition. Relationships between native and endemic species assemblage structure and environmental descriptors were assessed using canonical correspondence analysis (CCA). The first two axes of the canonical correspondence analysis explained 62.57% of the variation in the data. Of the nine environmental descriptors analyzed, eight significantly affected species distribution; however, electrical conductivity and elevation were most influential. Our study provides up-to-date status information on the distribution of freshwater fishes in the Karun River basin. This information is essential for developing conservation and management strategies to support the long-term sustainability of fish populations in the Karun River basin.

A fish-based multi-metric assessment index in the Karun River basin, Iran

Large river systems are one of the most important water resources for human societies. However, the ecological integrity of large rivers has been altered greatly by human activities. To monitor and manage these ecosystems, multimetric indices (MMI) are considered as efficient tools. This study aimed to develop and validate a fish-based multimetric index for the Karun River basin, Iran (Karun fish-based multi-metric index [KFMMI]). Eighteen rivers and 54 sites in the basin were sampled in July-August 2019, and physico-chemical and habitat characteristics were used to identify reference sites based on principal components analysis (PCA). Of the 54 sites, 14, 26, and 14 sites were classified as least, moderate, and most disturbed sites, respectively. Fifty-four candidate metrics were evaluated for range, responsiveness, and redundancy with other metrics. This resulted in the identification of eight metrics (relative abundance of native and endemic taxa, relative richness of migratory taxa, relative richness of Leuciscidae taxa, relative richness of herbivorous taxa, relative abundance of cyprinid taxa, relative richness of vegetative inhabitant taxa, relative abundance of slow water flow, and relative richness of edge inhabitant taxa) that informed on species richness and composition, migratory status, functional feeding groups, and habitat preferences. The KFMMI showed excellent performance in separating least, moderate, and most disturbed sites in our study area. Regarding water quality, the KFMMI was classified 16, 5, and 29 sites as good, moderate, and bad, respectively. The discrimination efficiency of KFMMI was 81.6%, which makes it an effective management tool for directing restoration actions at most disturbed sites and intensifying protection of least disturbed sites.

Checklist of digenean trematodes of Iran

Digeneans are an important class of trematodes which infect variety of animals ranging from vertebrates (mainly final hosts) to invertebrates (mainly as intermediate hosts). Additionally, some of these parasites are zoonotic and one health importance. Diversity of digeneans in Iran and reports of several zoonotic cases show the importance of these parasites in this country. This is the checklist of digenean parasites reported from Iran representing a total of 118 species, from 105 genera, 43 families, 21 subfamilies, and 3 orders that are reported from 139 species of different hosts including humans. Some of the most important final number of families, genera, and species reported in Iran fauna include: Fasciolidae, Genus: Fasciola, Fasciola gigantica, Fasciola hepatica, Family: Dicrocoeliidae, Genus: Dicrocoelium, Dicrocoelium dendriticum, Family: Diplostomidae, Genus: Diplostomum, Diplostomum spathaceum, Family: Heterophyidae, Genus: Haplorchis, Haplorchis taichui, Family: Notocotylidae, Genus: Notocotylu, Notocotylus aegyptiacus, Family: Bucephalidae, Genus: Rhipidocotyle, Rhipidocotyle illense.

Therapeutic Response of Epimedium gandiflorum's Different Doses to Restore the Antioxidant Potential and Reproductive Hormones in Male Albino Rats

Current study was planned to explore the therapeutic response of different doses of hydroethanolic extract of Epimedium grandiflorum leaves in male albino rats. Phytochemical analysis, HPLC and FTIR spectroscopy results revealed the presence of wide range of phenolic compounds and functional groups, respectively. Further, extract not induced significant hemolysis (7.56 ± 1.297%) against PBS (3.65 ± 0.35%) as negative control; while have significant clot lysis (44 ± 5.2%) potential, exhibited DPPH (78.87 ± 5.427%) scavenging, H2O2 (31.82 ± 3.491%) scavenging, antioxidant and reducing power activities. In vivo experimentation in albino male rats' revealed that administration of different doses (50, 100, 200 mg/Kg b.w.) of extract orally for 42 days after CCl4 intoxication significantly (P < 0.05) restore the selected parameters including liver enzymes, renal profiles, and stress markers and significantly (P < 0.05) increased reproductive hormones like testosterone, luteinizing hormone, follicle stimulating hormone and prolactin while significantly (P < 0.05) decreased progesterone and estradiol toward normal in dose dependent manner. Significant (P < 0.05) improvement in the structural architecture of testicular tissue particularly in high dose group (200 mg/Kg b.w.) was also observed. Results revealed E. grandiflorum has significant therapeutic response to address the healthcare problems particularly of impotency.

DNA barcoding and species delimitation of the Old World tooth-carps, family Aphaniidae Hoedeman, 1949 (Teleostei: Cyprinodontiformes)

The fishes, which have currently named Aphanius Nardo, 1827 are the relict of the ancient ichthyofauna of the Tethys Sea. For a long time since 1827, the genus name has been subjected to revision by several researchers using mainly morphological features. Until recently, no comprehensive single- or multi-locus DNA barcoding study has been conducted on whole members of the family Aphaniidae. In the present study, by applying four conceptually different molecular species delimitation methods, including one distance-based method, one network-based and two topology-based methods, we examined a single-locus DNA barcode library (COI) diversity for the 268 sequences within the family Aphaniidae from the Old World (57 sequences are new in the present study and 211 sequences were retrieved from NCBI database). The molecular analyses revealed a clearer picture of intra-family relationships and allowed us to clarify the generic names, and also describe a new genus for the family Aphaniidae. Results supported distinction of three major clades related to three genera within this family: i) the first clade includes the A. mento group which are placed in a new genus, Paraphanius gen. nov., found in the Orontes (= Asi) and Tigris-Euphrates River drainage, the Levant in coastal waters and the Dead Sea basin, western Jordan, and in southern Turkey in the Mediterranean basins as well as in central Turkey. This clade positioned at the base of the phylogenetic tree, (ii) the second clade contains the A. dispar-like brackish water tooth-carps which are transferred to the genus Aphaniops Hoedeman, 1951 (type species, Lebias dispar), distributed in the coastal waters around the Red Sea and the Persian Gulf basins; and (iii) the third clade, the genus Aphanius Nardo, 1827 (type species Aphanius nanus = A. fasciatus) contains all the inland and inland-related tooth-carps, which are mainly distributed in the inland waters in Turkey and Iran and also in the inland-related drainages around the Mediterranean basin.

A new species of the genus Capoeta Valenciennes, 1842 from the Caspian Sea basin in Iran (Teleostei, Cyprinidae)

A new species of algae-scraping cyprinid of the genus Capoeta Valenciennes, 1842 is described from the Kheyroud River, located in the southern part of the Caspian Sea basin in Iran. The species differs from other members of this genus by a combination of the following characters: one pair of barbels; predorsal length equal to postdorsal length; maxillary barbel slightly smaller than eye's horizontal diameter and reach to posterior margin of orbit; intranasal length slightly shorter than snout length; lateral line with 46-54 scales; 7-9 scales between dorsal-fin origin and lateral line, and 6-7 scales between anal-fin origin and lateral line.

Capoeta coadi, a new species of cyprinid fish from the Karun River drainage, Iran based on morphological and molecular evidences (Teleostei, Cyprinidae)

As presently recognized, the genus Capoeta includes 24 species, nine of which are known to occur in Iran (Capoetaaculeata, Capoetacapoeta, Capoetabuhsei, Capoetadamascina, Capoetafusca, Capoetaheratensis, Capoetamandica, Capoetasaadii and Capoetatrutta) and are distributed in almost all Iranian basins except Sistan and Mashkid. Capoetacoadisp. n. is a new species from the Karun River, southern Iran, draining into the Arvand Rud (Shatt al-Arab) which drains into the Persian Gulf. It is distinguished from all other species of Capoeta by the combination of the following characters: elongate and usually cylindrical body; 8–9 branched dorsal-fin rays; last unbranched dorsal-fin ray weakly to moderately ossified and serrated along 1/3–2/3 of its length; scales small; 70-84 in lateral line (total); 12–17 scales between dorsal-fin origin and lateral line; 9-11 scales between anal-fin origin and lateral line; 26–32 circum-peduncular scales; 10–13 gill rakers on lower limb of first gill arch; 45–47 total vertebrae; one posterior pair of barbels; bright golden-greenish or silvery body coloration in life; length of the longest dorsal-fin ray 15–22% SL; head length 23–26% SL; mouth width 7–10% SL. Capoetacoadi is also distinguished from all other congeners in the Iranian drainages by fixed diagnostic nucleotide substitutions in the mtDNA COI barcode region and cyt b. It is nested in the Capoetadamascina species complex.

Iranocichla persa, a new cichlid species from southern Iran (Teleostei, Cichlidae)

Iranocichlapersasp. n. is described from the Shur, Hasanlangi and Minab River drainages flowing into the Persian Gulf at the Strait of Hormuz in southern Iran. It is distinguished from Iranocichlahormuzensis, from the Mehran River drainage, by nuptial males having a bright orange breast and lower part of the head (vs. black), a poorly developed or invisible (vs. distinctive) “Tilapia-mark” in the dorsal fin and very clear white spots making almost wavy bars or stripes on the caudal fin (vs. without or with very few white spots). Mitochondrial DNA sequence characters suggest that both Iranocichla species are closely related but form two distinct clades, diagnosable by several fixed mutations in ND2, D-loop and partially by COI sequences. Populations from Kol River drainage, which is situated in-between the Mehran and the Shur River drainages, are more similar to Iranocichlahormuzensis in terms of their male nuptial coloration but to Iranocichlapersasp. n. in their mitochondrial sequence characters. Their status requires further investigation.

Phylogenetic relationships of freshwater fishes of the genus Capoeta (Actinopterygii, Cyprinidae) in Iran

The Middle East contains a great diversity of Capoeta species, but their taxonomy remains poorly described. We used mitochondrial history to examine diversity of the algae‐scraping cyprinid Capoeta in Iran, applying the species‐delimiting approaches General Mixed Yule‐Coalescent (GMYC) and Poisson Tree Process (PTP) as well as haplotype network analyses. Using the BEAST program, we also examined temporal divergence patterns of Capoeta. The monophyly of the genus and the existence of three previously described main clades (Mesopotamian, Anatolian‐Iranian, and Aralo‐Caspian) were confirmed. However, the phylogeny proposed novel taxonomic findings within Capoeta. Results of GMYC, bPTP, and phylogenetic analyses were similar and suggested that species diversity in Iran is currently underestimated. At least four candidate species, Capoeta sp4, Capoeta sp5, Capoeta sp6, and Capoeta sp7, are awaiting description. Capoeta capoeta comprises a species complex with distinct genetic lineages. The divergence times of the three main Capoeta clades are estimated to have occurred around 15.6–12.4 Mya, consistent with a Mio‐Pleistocene origin of the diversity of Capoeta in Iran. The changes in Caspian Sea levels associated with climate fluctuations and geomorphological events such as the uplift of the Zagros and Alborz Mountains may account for the complex speciation patterns in Capoeta in Iran.

Molecular Phylogeny and Zoogeography of the Capoeta damascina Species Complex (Pisces: Teleostei: Cyprinidae)

Capoeta damascina was earlier considered by many authors as one of the most common freshwater fish species found throughout the Levant, Mesopotamia, Turkey, and Iran. However, owing to a high variation in morphological characters among and within its various populations, 17 nominal species were described, several of which were regarded as valid by subsequent revising authors. Capoeta damascina proved to be a complex of closely related species, which had been poorly studied. The current study aims at defining C. damascina and the C. damascina species complex. It investigates phylogenetic relationships among the various members of the C. damascina complex, based on mitochondrial and nuclear DNA sequences. Phylogenetic relationships were projected against paleogeographical events to interpret the geographic distribution of the taxa under consideration in relation to the area’s geological history. Samples were obtained from throughout the geographic range and were subjected to genetic analyses, using two molecular markers targeting the mitochondrial cytochrome oxidase I (n = 103) and the two adjacent divergence regions (D1-D2) of the nuclear 28S rRNA genes (n = 65). Six closely related species were recognized within the C. damascina complex, constituting two main lineages: A western lineage represented by C. caelestis, C. damascina, and C. umbla and an eastern lineage represented by C. buhsei, C. coadi, and C. saadii. The results indicate that speciation of these taxa is rather a recent event. Dispersal occurred during the Pleistocene, resulting in present-day distribution patterns. A coherent picture of the phylogenetic relationships and evolutionary history of the C. damascina species complex is drawn, explaining the current patterns of distribution as a result of paleogeographic events and ecological adaptations.

A molecular approach to the genus Alburnoides using COI sequences data set and the description of a new species, A. damghani, from the Damghan River system (the Dasht-e Kavir Basin, Iran) (Actinopterygii, Cyprinidae)

The molecular status of nine species of the genus Alburnoides from different river drainages in Iran and additionally by seven species from Europe was assessed. mtDNA COI gene sequences from freshly collected specimens and available NCBI data revealed four major phylogenetic lineages. Based on the results, a distinct taxon from the Cheshmeh Ali (Ali Spring), a Damghan River tributary in the endorheic Dasht-e Kavir basin, northern Iran, which is the closest sister to Alburnoides namaki (Namak Lake basin) + Alburnoides coadi (Nam River in the endorheic Dasht-e Kavir basin) is considered as a new species, Alburnoides damghani sp. n. It is distinguished from other Alburnoides species in Iran by a combination of character states including: a weakly-developed, variably-scaled, ventral keel from completely scaleless to completely scaled, a short snout with the tip of the mouth cleft on a level with the lower margin of the pupil or slightly lower, a small eye (eye horizontal diameter slightly to markedly less than interorbital width), commonly 8½ branched dorsal-fin rays, commonly 11-12½ branched anal-fin rays, 40-46(47) total lateral-line scales, 2.5-4.2 or 2.5-4.1 pharyngeal teeth, gill rakers short and widely spaced, 6-8 in total, 39-41 (commonly 40), total vertebrae, (19)20(21) abdominal vertebrae, 19-21 (most commonly 20) caudal vertebrae, abdominal vertebral region most commonly equal to or longer than caudal region, and most common vertebral formulae 20+20 and 21+19.

Genetic connectivity and phenotypic plasticity in the cyprinodont Aphanius farsicus from the Maharlu Basin, south-western Iran

Meristic and morphometric characteristics, including otolith data, of the Farsi tooth-carp Aphanius farsicus, which is endemic to the endorheic Maharlu Basin in south-western Iran, were analysed for a sample of 92 individuals from four spring-streams; DNA sequence data (cytochrome b gene) are presented for 29 specimens. Some phenotypic variation was detected but the genetic data clearly indicate connectivity between the populations. Possible links between phenotypic variation and environmental variables such as water temperature, habitat size and absence or presence of predators and competitors are discussed. Based on a literature survey and the new data, it is concluded that population connectivity is maintained during times of droughts via large aquifers that formed during the late Pliocene to early Pleistocene, when the extant endorheic Maharlu Basin was created. Based on new data presented here and previous work, it is apparent that plastic and constant characteristics are present in Aphanius species, and that, if a population becomes isolated, a given trend of evolution may give rise to a taxonomically useful characteristic.

A new fish-based multi-metric assessment index for cyprinid streams in the Iranian Caspian Sea Basin

A major issue for water resource management is the assessment of environmental degradation of lotic ecosystems. The overall aim of this study is to develop a multi-metric fish index for the cyprinid streams of the Caspian Sea Basin (MMICS) in Iran. As species diversity and composition as well as population structure in the studied streams are different to other regions, there is a substantial need to develop a new fish index. We sampled fish and environmental data of 102 sites in medium sized streams. We analysed human pressures at different spatial scales and determined applicable fish metrics showing a response to human pressures. In total, five structural and functional types of metrics (i.e. biodiversity, habitat, reproduction, trophic level and water quality sensitivity) were considered. In addition, we used 29 criteria describing major anthropogenic human pressures at sampling sites and generated a regional pressure index (RPI) that accounted for potential effects of multiple human pressures. For the MMICS development, we first defined reference sites (least disturbed) and secondly quantified differences of fish metrics between reference and impaired sites. We used a Generalised Linear Model (GLM) to describe metric responses to natural environmental differences in least disturbed conditions. By including impaired sites, the residual distributions of these models described the response range of each metric to human pressures, independently of natural environmental influence. Finally, seven fish metrics showed the best ability to discriminate between impaired and reference sites. The multi-metric fish index performed well in discriminating human pressure classes, giving a significant negative linear response to a gradient of the RPI. These methods can be used for further development of a standardised monitoring tool to assess the ecological status and trends in biological condition for streams of the whole country, considering its complex and diverse geology and climate.

Predicting presence and absence of trout (Salmo trutta) in Iran

Species distribution modelling, as a central issue in freshwater ecology, is an important tool for conservation and management of aquatic ecosystems. The brown trout (Salmo trutta) is a sensitive species which reacts to habitat changes induced by human impacts. Therefore, the identification of suitable habitats is essential. This study explores the potential distribution of brown trout by a species distribution modelling approach for Iran. Furthermore, modelling results are compared to the distribution described in the literature. Areas outside the currently known distribution which may offer potential habitats for brown trout are identified. The species distribution modelling was based on five different modelling techniques: Generalised Linear Model, Generalised Additive Model, Generalised Boosting Model, Classification Tree Analysis and Random Forests, which are finally summarised in an ensemble forecasting approach. We considered four environmental descriptors at the local scale (slope, bankfull width, wetted width, and elevation) and three climatic parameters (mean air temperature, range of air temperature and annual precipitation) which were extracted on three different spatial extents (1/5/10 km). The performance of all models was excellent (≥0.8) according to the TSS (True Skill Statistic) criterion. Slope, mean and range of air temperature were the most important variables in predicting brown trout occurrence. Presented results deepen the knowledge about distribution patterns of brown trout in Iran. Moreover, this study gives a basic background for the future development of assessment methods for riverine ecosystems in Iran.

Comparative morphology of the sagittal otolith in three species of south Caspian gobies

Sagittal otolith shapes were investigated in order to identify three sympatric species of south Caspian gobies (Caspian goby Neogobius caspius, deepwater goby Ponticola bathybius and bighead goby Ponticola gorlap). The sagittal otoliths in P. bathybius have a rectangular shape and are thick, whereas in N. caspius they are relatively round and thin. In P. gorlap, otoliths have an elongated shape and are relatively thick. The noticeable difference among the otoliths of the three species is the presence of one anterior and one posterior projection in the otoliths of N. caspius and P. gorlap. Among shape indices, form factor (irregularity of surface area), circularity, aspect ratio and rectangularity are the foremost that indicate interspecific variability. The canonical discriminant analysis correctly classifies 94·7% of the original group cases. The overall analyses show the relevance of applying otolith shape for interspecific distinction of the three species of Caspian gobies.

Mitochondrial Genetic Differentiation of Spirlin (Actinopterigii: Cyprinidae) in the South Caspian Sea basin of Iran

Background

Knowledge about Alburnoides remains lacking relative to many other species, resulting in a lack of a systematic position and taxonomic diagnosis. Basic biological information for Alburnoides has been constructed, and it is necessary to understand further and obtain more information about this species. Its phylogenetic relationships are still debated and no molecular data have been used to study this taxon in Iran. A holistic approach for genetic methods was adopted to analyze possible spirlin population differences at selected centers in the south Caspian Sea basin of Iran.

Methods

The phylogenetic relationships were determined based on 774 base pairs of the mitochondrial cytochrome b gene of 32 specimens of spirlin from nine locations in the south Caspian Sea drainage basin of Iran. The nucleotide sequences were subjected to phylogenetic analysis using the neighbor-joining, maximum parsimony, maximum likelihood, and Bayesian methods.

Results

The mitochondrial gene tree largely supports the existence of three major clades. The western populations (clade I) may be considered as Alburnoides eichwaldii, whereas the Talar river populations (clade II) are represented as Alburnoides sp.1 and the eastern populations (clade III) may be distinct taxa of Alburnoides sp.2.

Conclusion

This molecular evidence supports the hypothesis that A. bipunctatus does not exist in the south Caspian Sea basin of Iran, and that the western and eastern populations are distinct taxa.