Garra mondica , a new species from the Mond River drainage with remarks on the genus Garra from the Persian Gulf basin in Iran (Teleostei: Cyprinidae)

A new bitterling from the Rhodeus amarus group is described based on morphological and molecular data. Rhodeus caspius sp. nov. from the Caspian Sea, Urmia Lake and the upper Tigris River drainages in Iran, is distinguished from its closest congeners (R. amarus and R. colchicus) by having short post-dorsal distance and caudal peduncle length and long head length. It is also characterized by one fixed diagnostic nucleotide substitutions and a K2P nearest neighbor distance of 1% to R. amarus and R. colchicus in the mtDNA COI barcode region.

This study uses mtDNA sequence data (cytochrome b) to explore the phylogenetic relationships between the tooth-carp Aphanius pluristriatus (Teleostei: Cyprinodontidae) in the Zarjan spring and two newly discovered Aphanius populations from the Khonj and Jahrom localities. All study sites are situated in the exorheic Mond River drainage of the Persian Gulf Basin in southwestern Iran. Maximum-likelihood and Bayesian-likelihood analyses reveal that A. pluristriatus and the two new populations represent a monophyletic clade, which is closely related to A. sophiae from the endorheic Kor River basin in the High Zagros and to A. mesopotamicus from the exorheic Tigris River system in southwestern Iran. However, comparative morphological analyses using morphometric and meristic characters indicate that the Khonj population differs slightly from the other two populations in the Mond River drainage, and the mtDNA data corroborate this conclusion. The Khonj population is therefore denominated as Aphanius cf. pluristriatus. These findings clearly indicate that A. pluristriatus has a wider distribution in the Mond River drainage than previously thought, and that intraspecific differentiation is present. The close phylogenetic relationships among A. pluristriatus, A. mesopotamicus and A. sophiae, their previously inferred recent ages of divergence, and the patterns of affinity among further freshwater fish species in the Persian Gulf, Tigris and Kor River drainage basins all suggest that these now isolated river systems were interconnected during the Last Glacial Maximum of the Late Pleistocene (21,000-18,000 y. BP) and remained so until the sea-level rise of the Early Holocene (11,000 y. BP).

Garra is the most species-rich genus of freshwater fishes in the Arabian Peninsula, including Oman, which has eight recognized, species restricted mainly to the Hajar and Dhofar mountains. Garra species from the Dhofar region in Oman are reviewed based on integrated morphological and molecular (COI) data of newly collected fishes from the type localities of G. sindhae and G. smartae, and a new population from Wadi Laggashalyon. No diagnostic character was found to distinguish the two species and the Laggashalyon population as distinct taxa. Garra dunsirei, another species endemic to a sinkhole at Tawi Attair, a very difficult area to access at a depth of about 211 m, was examined here based on the GenBank data and the diagnostic characters given in the original descriptions of the studied Garra species. In addition, the phylogenetic tree placed the sequenced Omani Garra fishes into nine groups with K2P sequence divergence of 0.8% (G. smartae and G. smartae_Laggasaylon); 1.2% (G. smartae and G. sindhae), and 14.5% (G. Shamal and G. dunsirei) in their COI barcode region. A molecular species delimitation approach using PTP, also detected one entity for Garra species from the Dhofar region (G. dunsirei, G. sindhae and the both populations of G. smartae), which is consistent with our morphological data. Therefore, based on absence of diagnostic characters, low genetic distance, and molecular species delimitation approach, we treat G. sindhae and G. smartae as junior synonyms of G. dunsirei.