Mülayim: Species composition and seasonal variation of peracarids (Crustacea: Peracarida) of the Istanbul Strait (Turkey) - 8321 - SPECIES COMPOSITION AND SEASONAL VARIATION OF PERACARIDS (CRUSTACEA: PERACARIDA) OF THE ISTANBUL STRAIT (TURKEY) MÜLAYİM, A. Department of Biology, Faculty of Science, Istanbul University, 34134 Vezneciler, Istanbul, Turkey (e-mail:
[email protected]; phone: +90-532-597-8093) (Received 18th Aug 2020; accepted 22nd Oct 2020) Abstract. The Istanbul Strait connects the Black Sea with the Sea of Marmara and it has a two-layered water system. In this study, we determined the diversity of the Peracarid Crustacean fauna and the ecological characteristics of the area. The data produced in this study revealed 76 peracarid species in the Istanbul Strait, of which five species (Animoceradocus semiserratus (Spence Bate.1862), Echinogammarus stocki G. Karaman, 1973, Leptocheirus bispinosus Norman, 1908, Cymodoce spinosa (Risso, 1816), Gnathia dentata (G. O. Sars, 1872)) were reported for the first time in the Sea of Marmara. The physicochemical properties of the seawater as well as total organic and inorganic carbon, and mud percentages of the sediment were analyzed at the sampling stations. In these stations, no significant relationship was determined between temperature, salinity, dissolved oxygen parameters and species or individual numbers. However, a positive relationship was found between the mud percentage and species and individual numbers. In contrast, at the hard bottom stations the number of individuals was positively associated with temperature and negatively with dissolved oxygen. Keywords: Crustacea, species diversity, hard and soft bottom habitats, ecology, Sea of Marmara Introduction The Istanbul Strait (also known as the Bosphorus) connects the Black Sea with the Sea of Marmara.