5 research outputs found
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
Dressing down: convergent reduction of the mental disc in Garra (Teleostei: Cyprinidae) in the Middle East
In the Middle East, species of Garra are believed to have invaded the area in two independent waves from the Indo-Malayan biogeographic region. This hypothesis is based on the structure of the mental disc, a unique specialization of the lower lip, which is believed to be an adaptation to fast-flowing waters. While several species have such a mental disc, others completely lack a mental disc, being adapted to slow-moving water or to subterranean life. In this study, the phylogenetic relationships of Middle Eastern Garra species, including 16 described and 4 undescribed species, were analysed using mitochondrial cytochrome c oxidase I sequences. The results are concordant with traditional hypotheses on two invasion events; however, these invasion events are independent from the presence, absence or shape of the mental disc. We postulate convergent reduction of the mental disc in 5-6 independent lineages of Garra in the Middle East