Aphanius Species Research Articles

The occurrence, distribution and biology of invasive fish species in fresh and brackish water bodies of NE Morocco

Monitoring the presence and expansion of alien species and upgrading their biological and ecological knowledge seems crucial to mitigate their possible impact on native communities. Within inland superficial waters, alien fish represent an important threat to the biodiversity and studies on their impact on native communities have increased around the world in the last years. However, little is known about their occurrence, biology and influences in North Africa in general, and more specifically in Morocco. In the present work we aimed to: 1) investigate the presence of any native Aphanius species, especially the Mediterranean killifish Aphanius fasciatus recorded from the lower basin of the Moulouya River (NE Morocco); 2) monitor the presence and expansion of two invasive species, the eastern mosquitofish Gambusia holbrooki and the mummichog Fundulus heteroclitus; and 3) contribute to the understanding of the ecological and abiotic affinities that govern the distribution of these alien fishes in North Africa. To achieve these goals, several field sampling campaigns were carried out between 2014 and 2018 across eastern Morocco, comprising the administrative Oriental Region and the Moulouya River Basin and covering an area of 119,268 km2. No native Aphanius species were found. The eastern mosquitofish has invaded the freshwater hydrosystems of the northern part of Morocco, including the study area, while the mummichog is currently limited to the brackish and salty wetlands of Lower Moulouya. Our results show that the known ranges of these two alien species have expanded. Data published through GBIF (Doi:10.15470/2qed9o)

Is the hybridization phenomenon traceable in the otolith and scale of extant Aphanius species? – A case study on hybrid offsprings of Aphanius farsicus X A. sophiae (Teleostei: Aphaniidae)

AbstractThe otolith and scale were analysed in the hybrid offsprings between two Aphanius species, that is, A. farsicus and A. sophiae to evaluate if they are suitable to trace hybridization. An artificial reciprocal hybridization was performed between two species. The hybrids of A. farsicus♂ × A. sophiae♀ had otoliths with long and pointed rostrum with a narrow depression in the middle of the ventral rim. The otoliths of hybrids between A. farsicus♀ × A. sophiae♂ were more close to A. sophiae♂. As a result, the otolith contour of the hybrids was intermediate to those of the parents. Therefore, we suggest that some variations observed in the otoliths of Aphanius species may be resulted by hybridization particularly when they are sympatric or has geographic overlap. Also, no remarkable differences were found between the scales of hybrids and parents. This indicated that scale morphology and surface microstructures are not suitable for tracing the hybridization. If these species are sympatric due to possible translocation, it causes the genetic introgression of a native species through hybridization. This must be particularly considered in the conservation programme of endangered A. farsicus because artificial transplantation and consequent hybridization can lead to the extinction of this critically endangered species.

The First Complete Mitochondrial Genome Sequence in the Genus Aphanius (Teleostei)

In the present study, for the first time we isolated and characterized the complete mitochondrial genome sequence of the endangered Farsi killifish Aphanius farsicus by long polymerase chain reaction amplification, and primer walking methods. The circular mitogenome of A. farsicus consisting of 16 485 base pairs encodes 13 polypeptides (protein-coding genes), the 12S and 16S ribosomal RNAs, and 22 transfer RNAs and an 884 bp D-loop control region. These genes are ordered in the same way as most other vertebrates. The overall nucleotide composition of this genome was 27.09 for A; 27.87 for T; 16.89 for G; and 28.14% for C (GC content of 45%, and AT content of 55%). The genus Aphanius has already been in the family Cyprinodontidae. However, the name Aphaniidae has recently been proposed as valid family for the members of the genus Aphanius (the Western Palaearctic killifishes), while the family Cyprinodontidae is restricted to the New World genera such as Cyprinodon, Floridichthys and Jordanella. Based on the phylogenetic relationships achieved in the present study, we recommend that the validation of family Aphaniidae still needs more phylogenetic supports, and this can be investigated by adding more sequences of the Aphanius species. The availability of this mitogenome will also provide a set of useful data for studying on population genetic diversity and molecular evolution and facilitate evaluations of A. farsicus genetic structure for management and conservation of this endangered species.

Scale morphology and phylogenetic character mapping of scale-surface microstructures in sixteen Aphanius species (Teleostei: Aphaniidae)

Recent studies on the analysis of the evolutionary relationships between the various taxa of the teleost fishes are based on the evaluation of the efficacy of different approaches, verifying the taxonomical congruence between the hypotheses inferred from molecular data and those from morphological data. The first objective of this study was to investigate the macro- and microscopic characterization of the body key scales for the sixteen Aphanius species, and to discuss their taxonomic significance. In addition, to reveal the phylogenetic origins of particular adaptations and to identify a possible cases of convergent evolution in scales of Aphanius species, we used a phylogenetic character mapping procedure that uses an independent data source, namely molecular data that is presumed to be functionally independent of the scale traits. Comparison of the resulted phylogenetic trees and scale data dendrogram implied that neither scale shape/scale surface morphology, nor scale surface microstructure can be used for the species identification and inferring phylogenetic relationships in the genus Aphanius. This conclusion confirms previous studies, indicating that the scale shape and ornamentations varies with habitat, age and size of the fish. We also concluded that the polygonal state in the scales of Aphanius species was a primitive shared character state.

Detection ofContracaecum multipapillatum(Nematoda: Anisakidae) in the indigenous killifishAphanius hormuzensis(Teleostei; Aphaniidae) and its histopathological effects: A review of IranianAphaniusspecies parasites

The present study reports the occurrence of Contracaecum multipapillatum (Nematoda: Anisakidae) in an indigenous small killifish, Aphanius hormuzensis Teimori, Esmaeili, Hamidan, Reichenbacher, 2018 from Southern Iran and shows its histopathology. A total of 110 A. hormuzensis specimens were collected from Shur (Naband) River, Hormuzgan basin in Southern Iran and examined for their possible parasitic infections. Third‐stage larva of C. multipapillatum was extracted for the first time from the body cavity of 19 fish specimens (one male and 18 female) and identified by molecular and morphological methods. In comparison with non‐infected fishes, the melanomacrophage centers were detected in the tissue sections from liver, kidney and spleen of all the parasite infected fishes. To date, 16 parasites belong to nine families have been recorded from six Aphanius species (out of 15 known species) in Iran. Among them, eight and four parasites have been identified from A. vladykovi, and A. hormuzensis respectively. Since Aphanius species are living in different environments, therefore, they seem to be good hosts for the different types of parasites, and more new parasites are expected to be found in these fishes.

Comparative morphology of urohyal bone in brackish water species of the genus Aphanius Nardo, 1827 in the Persian Gulf and Southeastern Mediterranean Sea basins (Teleostei: Aphaniidae)

Among the skeletal elements in fishes, the urohyal bone which lies in the lower part of the head - the central part of the mandibular skeleton- has proved to be of special significance in fish systematics. The urohyal bone is considered to be a synapomorphic structure in teleostean fish. The urohyal bone of six brackish water Aphanius species (i.e., Aphanius hormuzensis, A. stoliczkanus, A. furcatus, A. ginaonis, A. mento, A. sirhani) was compared using morphological description and linear measurements to explore the effectiveness of urohyal bone morphology in the separation of the Aphanius species. Description of the urohyal bones and their morphological variation allowed identification of the A. furcatus, A. mento and A. sirhani from their relatives. Moreover, the UH.UL separates significantly A. dispar and A. ginaonis, and the MH.UL discriminates significantly A. mento from others studied relatives. Discriminant function analysis (DFA) separated the studied species with high classification success (overall mean 94.7%). These results suggest the power of urohyal bone morphology in separating of the Aphanius species analyzed, and highlighting the taxonomic value of the urohyal bone. By considering the phylogenetic relationships among the studied species, it can be concluded that the observed variation in their urohyal morphology is largely consistent with their phylogeny. This indicated that at least some morphological characters in the shape of urohyal bone in Aphanius are encoded probably by genetic factors, which can be used for species discrimination.

The scale characteristics of two Aphanius species from southern Iran (Teleostei: Aphaniidae)

Fish scales are morphologically diverse among species, within species, and even among individuals. The present study investigated macro- and micromorphology of the scales between two closely related Aphanius species in southern Iran including Aphanius hormuzensis, collected from Gotab/Mehran River and A. stoliczkanus, from Howba hot sulphuric spring. The results indicated clear interspecific differences in scale macromorphology and microstructures. The scales of A. hormuzensis are characterised by a rounded shape, 7–9 (mean 8.0±0.83) primary radii, and a relatively large focus with oblong shape that positioned centrally on the scale, while the scales of A. stoliczkanus are characterised by a polygonal shape with few spines in posterior region, 8–11 (mean 10.0±0.78) primary radii and a small rounded focus that positioned posterocentraly on the scale. These species are morphologically close but clearly distinguished by their scale morphology and habitat requirements (e.g. water depth and food availability). Therefore, it can be assumed that clear differences in their scale morphology have been resulted by the combination of both genetic and environmental factors.

Systematics and historical biogeography of theAphanius disparspecies group (Teleostei: Aphaniidae) and description of a new species from Southern Iran

Among the species of Aphanius Nardo, 1827, Aphanius dispar (Ruppell, 1828) is the most common taxon and has long been viewed as representing a species group rather than a single species. This study provides comprehensive data on the phylogenetic relationships, morphology, and otoliths within the A. dispar species group, including the description of a new species. Our data demonstrate that the true A. dispar is restricted to the Sea drainages and that all other populations hitherto identified as A. dispar actually represent separate species. Four main clades are defined and named for the geographic areas in which the respective species of Aphanius occur. The oldest one is the Red Sea clade, it comprises A. dispar. The Dead Sea clade is represented by A. richardsoni (Boulenger, 1907). It is sister to both the Hormuzgan clade in S Iran (containing A. hormuzensis sp. nov. and A. ginaonis (Holly, 1929)) and the Persian Gulf & Gulf of Oman clade (comprising A. stoliczkanus (Day, 1872)). The species separation within the A. dispar group is confirmed by the distinctive otolith morphology of each species. Moreover, we present a time-calibrated phylogeny (chronogram) for the A. dispar species group using dagger A. princeps (16-17 Mya) as a minimum age and the first appearance of dagger Prolebias (33-34 Mya) as a maximum age for the genus Aphanius. The evolution and historical biogeography routes are discussed based on the outcome of the chronogram and in the context of the geological and climatic history of the Near East in Pliocene-Pleistocene times.

Microstructural characterization of the body key scale morphology in six Iranian endemic Aphanius species (Cyprinodontidae): Their taxonomic and evolutionary significance

The microstructural characteristics of the body key scales were described for six Iranian endemic Aphanius Nardo, 1827 species. Among them, five species genetically belong to the “Iranian inland and inland-related Aphanius species, IIRAS” group, while A. ginaonis (Holly, 1929) belongs to the “brackish water species” group. General scale shape in the studied Aphanius species was cycloid with the exception of A. ginaonis, which has cycloid scales with few spinous-like structures present in the posterior edge of the scales. Considering phylogenetic relationships of the studied taxa, the most likely explanation for presence of the spinous scales in Aphanius species is the primary existence of these scales in this group. In addition, among the IIRAS group, the most different lepidont was recognized in scales of the A. isfahanensis Hrbek, Keivany and Coad, 2006 (pointed), which is similar to lepidonts in the A. ginaonis. The scales of these species are polygonal with similar typology. The similarity in lepidont morphology between A. ginaonis and A. isfahanensis can explained by (i) the primary existence of the rounded lepidont in this group, and (ii) since A. ginaonis and A. isfahanensis belong to two separate phylogenetic lineages, therefore, similarity in their lepidont morphology could be results of convergent evolution.

Sympatry and possible hybridization among species of the killifish genus Aphanius Nardo, 1827 (Teleostei: Cyprinodontidae) in Southwestern Iran

Studies of the taxonomy and present-day distribution of landlocked populations of the killifish Aphanius Nardo, 1827 (Cyprinodontidae) provide a key to understanding their zoogeographic history, and shape conservation strategies and habitat management. Here we report for the first time on the sympatric occurrence of the rare Mesopotamian tooth-carp A. mesopotamicus with a member of the widely distributed common tooth-carp (A. dispar group). Both were found in the Shadegan Wetland of the Mesopotamian drainage system (Southwestern Iran). External characters of individuals, otolith morphology and molecular data based on the cytochrome b gene confirm species identification. The otolith morphology of A. mesopotamicus, hitherto unknown, is strikingly similar to previously described otoliths of A. cf. pluristriatus from the Khonj stream (Southern Iran), which apparently reflects a close relationship between these recently diverged species. Several of the specimens recovered from the Shadegan Wetland showed intermediate characters in pigmentation, otolith morphology and some morphometric values. These specimens are interpreted as putative hybrids, which is additionally supported by a multivariate analysis of the morphometric data. Previous reports suggest that natural hybridization between species of Aphanius results largely from range overlap and range extension. A virtual distribution map derived from climatic modelling studies based on DIVA-GIS (7.5.0) indicates that sympatry of the A. dispar group and A. mesopotamicus is primarily determined by levels of precipitation during the warmest quarter, and is likely to occur only in Southwestern Iran.

Length-weight and length-length relationships of eight endemic Aphanius species from Turkey

Summary Length–weight and length–length relationships were assessed for eight endemic Aphanius species from Turkey. This study provides a new reference on length–weight and length–length relationships and new maximum sizes for all species examined.

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.

Herbivory and seasonal changes in diet of a highly endemic cyprinodontid fish (Aphanius farsicus)

Trophic ecology is essential to understand ecosystem functioning and structure and assist biological conservation. Here we investigate, for the first time, the feeding ecology of Aphanius farsicus, a cyprinodontid fish endemic of a single landlocked river basin in central Iran. We sampled monthly a population of this fish species during a year and examined differences in food across seasons, sexes and sizes. Similarly to other cyprinodonts, A. farsicus showed sexual dimorphism and more abundance of females. Size structure and individual condition varied across seasons, with larger fish in spring and better condition in summer and less in winter. We found no empty guts, suggesting that these fish feed all year round due to the warm climate of its native distribution. Farsi toothcarp diet was based on detritus, algae (particularly diatoms, green algae, and cyanobacteria), and small invertebrates. Seasonal variation in diet was more important than variation due to fish size and the Farsi toothcarp consumed more green algae in spring and early summer and more diatoms and insects the rest of the year. Herbivory was considerable, similarly to a few other cyprinodonts, and increased with fish size, particularly because of higher consumption of green algae. As with species composition in diet, season was more important than size in the variation of number, biovolume, mean size, and diversity of prey captured, with higher number, richness and size of prey captured in summer. The ontogenetic diet shift was less marked in this cyprinodont than in many other Aphanius species, probably due to its reduced size and the resource availability of its habitat, but was also shown by size-dependent feeding selectivity for a few invertebrates.

New data on the zoogeography of Aphanius sophiae (Teleostei: Cyprinodontidae) in the Central Zagros (Southwest Iran)

The clade of the Iranian freshwater Aphanius species from endorheic and exorheic drainage basins contains three subclades, of which the Aphanius sophiae subclade with seven species is the most specious one. Recently, two previously not known populations of Aphanius were discovered in two isolated basins; one in the Arjan Wetland (Helleh subbasin), and the other in the Semirom spring (Karun Basin), both are located in the Central Zagros Mountains (SW Iran). The objective of this study is to investigate their taxonomic status, to elucidate their phylogenetic relationships and to contribute to future conservation strategies and habitat management of the freshwater species of Aphanius in Iran. Methods include analysis of genetic data based on mtDNA ( cyt b ), combined with meristics, morphometrics, scale sizes ( J -indices) and otolith data. The results based on cyt b clearly indicate that two species are present in the Arjan Wetland, one is closely related to A. sophiae (currently thought to be restricted to the Kor Basin), the other represents Aphanius shirini (previously only known from its type locality Paselari spring). However, significant phenotypic differences are not present between these two species. The second population from the Semirom spring is sister to A. sophiae (Kor Basin) according to cyt b data, but differs significantly from this species with regard to the phenotype. The presence of A. shirini in the Arjan Wetland is most likely be explained by man-made introduction because of the recent droughts. The similarity of the two species present in the Arjan Wetland may be due to phenotypic plasticity, but also hybridization could have played a role. The isolation of populations of A. sophiae is discussed in the context of the active geological history and climate change, and it is likely that their divergence happened in the Early or Middle Holocene (c. 11,700–4000 y. ago). The presence of A. sophiae in the Helleh subbasin and Karun Basin extends the currently known zoogeographic range of this species, which previously has only been reported from the Kor Basin. Such knowledge is important for future conservation strategies and habitat management.

Aphanius marassantensis, a new toothcarp from the Kızılırmak drainage in northern Anatolia (Cyprinodontiformes: Cyprinodontidae)

Aphanius marassantensis, new species, is described from the Kızılırmak River drainage in northern Anatolia based on colouration, meristic and morphometric characters, and the mtDNA COI barcode region. It is distinguished from other Anatolian Aphanius by one or several of the following characters: a stout body shape (BD/SL 28.2-39.6%), complete scale cover, and 25-28 scales along the lateral line. Males have 8-13 dark-brown lateral bars, of which the antepenultimate bar anterior to the caudal-fin base is 0.9-1.8 times wider than the anterior white interspace, 2-3 vertical rows of spots on the caudal fin, a black dorsal fin, sometimes with a narrow whitish-grey base, a white anal fin with 1-3 rows of black spots, in some individuals with a black margin, and hyaline pelvic fins. Females do not have vertical rows of dark-brown spots on caudal or anal fins, but numerous dark-brown spots on the flanks, arranged in 1-3 lateral rows behind a vertical from the dorsal-fin base. Their dorsal fin is hyaline with tiny dark-brown spots on rays and membranes; pectoral fins, caudal and anal fins are hyaline, and one prominent large dark-brown blotch is situated in mid-lateral position on the hypural plate. The new species is also distinguished by 11 fixed, diagnostic nucleotide substitutions in the mtDNA COI barcode region. The description of this new species, which brings the number of Anatolian Aphanius species to 12, underlines the character of Anatolia as a region of extraordinarily high biodiversity.

Two new species of the tooth-carp Aphanius (Teleostei: Cyprinodontidae) and the evolutionary history of the Iranian inland and inland-related Aphanius species.

Two new species of Aphanius are described from the Kol drainage in southern Iran (Aphanius darabensis n. sp.) and the endorheic Kavir Basin in northern Iran (A. kavirensis n. sp.), and compared with eight closely related species. Aphanius darabensis n. sp. is sister to A. shirini, from which it is distinguished by molecular characters (cytochrome b) and the combination of three morphological characters: 9-18 flank bars in males (vs. 7-10), females with irregular vertical patches of brown color on the flank (vs. prominent dark brown blotches of round or irregular shape), and symmetrically-shaped triangular to trapezoid otoliths with a rostrum distinctly longer than the antirostrum (vs. quadrangular to trapezoid otoliths with short and equally sized rostrum and antirostrum). Aphanius kavirensis n. sp. is closely related to a group containing A. sophiae, A. mesopotamicus and A. pluristriatus, from which it is distinguished by cytochrome b characters and the combination of three morphological characters: females with irregularly arranged large blotches of dark brown color on the flank, short pectoral fin in both sexes (13.4-18.1% SL in males, 11.2-18.3% SL in females), and asymmetrically shaped triangular to trapezoid otoliths with a pronounced predorsal region. Our tree based on the cytochrome b data demonstrates that the Iranian inland and inland-related Aphanius species (IIRAS) form a monophyletic clade with three subclades (A. vladykovi -, A. shirini -, A. sophiae subclades). The A. sophiae subclade, which is the most diverse of the three subclades, can be further divided into three lineages (A. isfahanensis -, A. farsicus -, A. sophiae lineages). The temporal diversification of the IIRAS clade is discussed and two evolutionary groups of Aphanius are depicted. Aphanius vladykovi, together with A. shirini, A. darabensis n. sp. and A. isfahanensis characterize the "old" evolutionary group. Their divergences may have happened 10-5 m.y. ago (Late Miocene-Early Pliocene). Aphanius farsicus, A. arakensis, A. sophiae, A. mesopotamicus, and A. pluristriatus, together with Aphanius kavirensis n. sp., represent the "young" evolutionary group, which developed in the Late Pleistocene (100,000-11,700 y. ago) and Early to Middle Holocene (c. 11,700-4,000 y. ago).

A new and unique species of the genus Aphanius Nardo, 1827 (Teleostei: Cyprinodontidae) from Southern Iran: A case of regressive evolution

A primarily vicariance-based speciation has been suggested for the killifish genus AphaniusNardo, 1827, but ecological factors are likely to have promoted the speciation processes in addition. Here, we report on the discovery of a unique Aphanius species from Southern Iran and show that also regressive evolution has shaped the present-day diversity of Aphanius. The species is characterized by complete absence of scales and reduction in the biomineralization of hard structures, particularly of the caudal skeleton and jaw teeth. Based on mt-DNA sequences, morphometric and meristic data, osteology, jaw teeth and otoliths, it is described as Aphanius furcatus sp. n. The new species is sympatric with A. dispar (Rüppell, 1829) in salty rivers and hot sulphuric springs in the Hormuzgan Basin (Southern Iran), and is sister taxon to this species plus A. ginaonisHolly, 1929. Based on geological data we estimate that the divergence between the lineages of A. furcatus and A. dispar is about 12–14million years old. We conclude that the reductive phenomena observed in A. furcatus have evolved as an evolutionary response to the extreme habitat conditions in order to save energy (because storage of Ca2+ is not necessary), and to transport oxygen efficiently. The results confirm that regressive evolution is an important factor in speciation and occurs independently in separate lineages.

Phylogenetic analysis of Aphanius from the endorheic Kor River Basin in the Zagros Mountains, South-western Iran (Teleostei: Cyprinodontiformes: Cyprinodontidae)

Morphologically similar populations of Aphanius that are currently considered as A. sophiae inhabit the endorheic Kor River Basin in the Zagros Mountains. Using genetic analysis based on mtDNA (cytochrome b), combined with examination of morphology (morphometry, meristics, otoliths), we discovered that what is thought to be A. sophiae is actually two distinct species, one of which is described as A. shirini sp. n. The males of the new species can be distinguished from those of all other Iranian inland Aphanius species by having only 7–10 clearly defined white flank bars, which is the lowest number of flank bars among the Iranian inland Aphanius species. Both males and females differ from all other Iranian inland Aphanius species by having a significantly longer caudal peduncle and a smaller dorsal fin depth. Based on the PhyML and Bayesian likelihood trees, A. shirini is sister to A. vladykovi from the Karoun Basin in the Zagros Mountains. Our results indicate that an ancient exorheic Kor River Basin existed in the Late Miocene and Pliocene. The close phylogenetic relationship between A. shirini and A. vladykovi suggests that the pre-Pliocene drainage in the ancient Kor River Basin was directed to the north-west (to the Karoun Basin), and not to the south-east as in the present-day Kor Basin. Both A. shirini and A. vladykovi represent the highest altitude records for Aphanius. We conclude that the splits of A. shirini and A. vladykovi can be linked to tectonic events in the Middle to Late Miocene, which created the highest altitudes (>3000 m) in the Zagros Mountains, and led to isolation of populations. The present-day endorheic Kor Basin is known to have formed in the Late Pleistocene or Early Holocene, and the ‘young’ age of A. sophiae is clearly related to this history. Our results contribute to elucidate the link between geological history and the present-day species diversity in the tectonically still active Zagros Mountains of Iran.

Aphanius farsicus, a replacement name for A. persicus (Jenkins, 1910) (Teleostei, Cyprinodontidae)

Gaudant (2011) has shown that Brachylebias Priem, 1908 is a junior synonym of Aphanius Nardo, 1827 and that therefore the new name for the Late Miocene species Brachylebias persicus Priem, 1908 is Aphanius persicus (Priem, 1908). In addition, he stated that a new name has to be assigned to the extant A. persicus (Jenkins, 1910). However, before a new species name can be assigned, it is necessary to demonstrate that the two species, currently named A. persicus, are different. Here we show that slight differences are present in the meristic characters between the fossil A. persicus (Priem, 1908) and the extant A. persicus (Jenkins, 1910), and that clear differences are present with regard to the size and morphology of the scales and also with regard to the shape of the jaw teeth. We demonstrate that the epithets blanfordii and pluristriatus, both introduced for Aphanius species by Jenkins (1910), do not represent alternative names, and we introduce A. farsicus as replacement name for A. persicus (Jenkins, 1910).

The endangered cyprinodont Aphanius ginaonis (Holly, 1929) from southern Iran is a valid species: evidence from otolith morphology

Aphanius Nardo, 1827 (Actinopterygii, Cyprinodontidae) is a widely distributed genus in the Mediterranean and Persian Gulf area and includes several endangered species. The otolith morphology in Aphanius is known to represent a valuable tool for the taxonomy, and is also indicative for the genetic diversity of a particular population. The present study focuses on the otoliths of the endangered A. ginaonis (Holly, 1929), which is endemic to the Geno hot spring in southern Iran. The taxonomic status of A. ginaonis has repeatedly been questioned, and some scholars have argued that it merely represents a morphological variation of the widespread A. dispar. We present a comparison of the otolith morphology of A. ginaonis (52 specimens) with that of A. dispar (Ruppell, 1828) from the Mehran River Basin (southern Iran) (17 specimens) and an A. dispar population from the Persian Gulf coast of the United Arab Emirates (32 specimens). Our data obtained from SEM pictures, otolith morphometry and statistical analyses suggest that A. ginaonis represents a valid species. In A. ginaonis individuals with a standard length exceeding 23 mm, the otolith variables length–height and rostrum length represent useful complementary diagnostic characters discriminating this species from other Aphanius species. Besides ontogenetic variation, we found extremely high otolith form variability in A. ginaonis, including some otoliths with a morphology distinctly deviating from the basic morphology type. We hypothesize that these variations may be a result of the artificial introduction of A. dispar into the Geno hot spring during the last years and subsequent hybridisation.