Short communication: A study of food consumption of the deepwater goby, Ponticola bathybius (Kessler, 1877), during spring migration in the southern Caspian Sea

The gobies exhibit a main role in the general production of the Caspian Sea due to their species diversity and unexploited stocks. So, of the 80 fish species known from Iranian part of the Caspian Sea, 10 of them are gobies. The deepwater goby, Ponticola bathybius (Kessler, 1877), Gobiidae, is a native species in the Caspian Sea which settles on sandy and shelly substrates and, in a few numbers, on firm silt down to 75 meters. The presence of predators such as Acipenseridae and prey items as Clupeonella sp. could be effective in the abundance of gobies. Gobies fishes are known as the great consumers of food resources and the considerable competitors for other species. ... In Iranian coastal waters of the Caspian Sea, there are differences in some important ecological factors including substrate type, slope and light intensity which may affect the prey community. Therefore, this study was carried out to compare dietary composition of P. bathybius at three different localities (Bandar-e-Anzali, Salmanshahr and Miankaleh) along the southern Caspian Sea coastal waters.