Ponticola iranicus sp. nov. (Actinopterygii: Perciformes: Gobiidae) from the Caspian Sea basin

Abstract

Background. Five species of Ponticola have hitherto been recognized among freshwater gobies in the Ponto-Caspian basin. In 2014 a number of specimens representing this genus were collected in northern Iran. The detailed morphological and karyological study of those gobies collected revealed signifi cant differences between them and their known congeners. The aim of this study was to describe these fi sh as a new species from the Caspian Sea basin. Materials and methods. The fi sh specimens were collected in August 2014 at two localities of the Sefi d-Rud River drainage, and in the Gisum River, Guilan Province, northern Iran. In total, 18 specimens were used for karyological study following a previously described method. Both karyotyped and intact specimens were then morphologically investigated using characters developed for study on gobiids, and particular for freshwater Caucasian gobies. The comparative materials were specimens from museum collections, as well as published descriptions, illustrations, and measurements of other species. Results. Ponticola iranicus sp. nov. differs from its congeners in a set of the following features: D 1 VI, D 2 I/(14½) 15½-17½, A I/10½-13½; nape scaled completely, scales cycloid; cycloid scales covering upper part of opercle; lateral line system with posterior sub-orbital row d 2 continuous; predorsal area uniform, dark grey; fi rst dorsal fi n with oblique black stripe between fi rst two or three rays; short dark grey strip on upper part of pectoral fi n base; karyotype consisting of 46 acrocentric chromosomes. Conclusion. All known Ponto-Caspian gobies demonstrate mosaic pattern of morphological and karyological features that presumes their polyphyletic origins. Further phylogenetic studies by molecular genetic methods are necessary for identifi cation of their marine ancestors and clarifying of common trends in the evolution of the Ponto-Caspian goby group.

Taxonomic diversity and distribution of the genus Proterorhinus (Teleostei: Gobiidae) in the Caucasus biodiversity hotspot with conservation implications

“…Proterorhinus sp. and P. nasalis ), the CBH is also the stage of endemic evolution for another Ponto‐Caspian gobiid genus Ponticola Iljin, 1927: Ponticola iranicus and Ponticola patimari endemic to the Iranian part of the CBH, Ponticola cyrius endemic to the Kura River, Ponticola constructor and Ponticola rhodioni endemic to the south and north of the Bzyb Range, respectively, and Ponticola rizensis and Ponticola turani endemic to the İyidere and Aksu streams of Turkey, respectively (Miller, 2003; Kovačić & Engin, 2008; Vasil'eva, Mousavi‐Sabet & Vasil'ev, 2015; Eagderi, Nikmehr & Poorbagher, 2020). Apart from the fact that their conservation status, like other Caucasian freshwater fish, has been incompletely assessed (Freyhof et al, 2020; IUCN, 2021), the known genetic, biological, ecological and distributional data on these species are also insufficient and systematic observations are needed for taking steps towards conservation.…”

An integrative insight into the diversity, distribution, and biogeography of the freshwater endemic clade of the Ponticola syrman group (Teleostei: Gobiidae) in the Caucasus biodiversity hotspot

“…Ponticola kessleri (Günther, 1861) and P. gorlap (Iljin, 1949) are euryhaline and are able to inhabit the sea as well as a wide range of freshwater habitats. In addition, there are several real freshwater endemics including P. constructor (Nordmann, 1840), P. cyrius (Kessler, 1874), P. iranicus Vasil'eva et al, 2015 , P. patimari Eagderi et al, 2020 , P. rhodioni (Vasil'eva & Vasil'ev, 1994), P. rizensis (Kovačić & Engin, 2008 ), P. turani (Kovačić & Engin, 2008 ), and P. hircaniaensis Zarei, Esmaeili, Kovačić, et al, 2022a , all endemic to small areas in the Caucasus Biodiversity Hotspot (CBH). Ponticola cyrius is endemic to the Kura River drainage from headwaters in Turkey down to Azerbaijan, P. constructor and P. rhodioni are endemic to the south and north of the Bzyb Mountain Range, respectively, P. rizensis and P. turani are endemic to the İyidere and Aksu streams in Turkey, respectively, and P. iranicus , P. patimari , and P. hircaniaensis are endemic to small areas of the Iranian part of CBH (Eagderi et al, 2020 ; Kovačić & Engin, 2008 ; Miller, 2003 ; Vasil'eva et al, 2015 ; Zarei, Esmaeili, Kovačić, et al, 2022a ).…”

“…Neilson and Stepien ( 2009a ) placed P. iljini with P. gorlap in their revised phylogenetic systematic classification, however, Vasil'eva et al ( 2016 ) proposed the validity of P. iljini in a karyological analysis but also restricted its distribution to the west coast of Kazakhstan, northern Caspian Sea. Morphological and karyological examination of Ponticola specimens from the Sefidrud and Gisum rivers in Iran by Vasil'eva et al ( 2015 ) identified noticeable differences with other species of Ponticola including P. cyrius , which led to the description of P. iranicus . Phylogenetic and species delimitation analyses of the south Caspian gobiids by Zarei, Esmaeili, Schliewen, et al ( 2021b ) only supported the presence of two species, P. gorlap and P. iranicus in the freshwater habitats of the SCB, indicating that the fishes previously identified by Ahnelt and Holčik ( 1996 ) as P. cyrius and P. iljini were in fact conspecific with P. iranicus and P. gorlap .…”

Length-weight and length-length relationships for two gobiids from the Anzali Wetland, in the southern Caspian Sea basin

“…The Caspian Sea basin belongs to the Ponto–Caspian biogeographical region, encompassing the basins of the Black, Azov, Caspian, and Aral Seas (Coad, ). The native fish fauna of the Caspian Sea basin consists of an estimated 162 fish species, 100 of them being endemic species or subspecies (Miller, ; Vasil′eva, Mousavi‐Sabet, & Vasil′ev, ); many of them of commercial importance. The fishes of the family Gobiidae inhabiting the area are usually less important commercially and therefore knowledge on their biodiversity is far from being complete (Miller, ; Vasil′eva et al., ).…”