Decapod Crustacean Fauna of the Black Sea Coasts of Istanbul
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Crustaceana 85 (8) 897-908 DECAPOD CRUSTACEAN FAUNA OF THE BLACK SEA COASTS OF ISTANBUL BY H. BALKIS1,3),A.MÜLAYIM˙ 1) and F. PERÇIN-PAÇAL˙ 2) 1) Istanbul University, Faculty of Science, Department of Biology, TR-34134 Vezneciler, Istanbul, Turkey 2) Istanbul University, Institute for Experimental Medical Research, Department of Genetics, TR-34093 Sehremini, Istanbul, Turkey ABSTRACT This study was carried out as a survey of the species of decapod Crustacea found along the Black Sea coasts of Istanbul. It also aims to report on some of their ecological properties. Samples were collected at 36 stations during 2000 and 2001 from depths of 0.5-65 m using a scoop net, dredge, beam-trawl, or trammel net. A total of 15 species of decapod crustaceans was identified. One of these, Philocheras fasciatus (Risso, 1816), is herein reported for the first time from the Turkish coastal waters of the Black Sea. Primary hydrographic conditions such as temperature (range 8.0- 21.8°C), salinity (16.7-17.8h), and dissolved oxygen (4.5-9.0 mg/l) were recorded at each sampling occasion. RÉSUMÉ Cette étude a été réalisée pour recenser les espèces de Crustacés décapodes trouvés le long des côtes de la mer Noire à Istanbul. Elle avait aussi pour but d’établir certaines de leurs caractéristiques écologiques. Des échantillons ont été collectés dans 36 stations en 2000 et 2001 à des profondeurs de 0,5 à 65 m en utilisant un filet écope, une drague, un chalut à perche, ou un trémail. Un total de 15 espèces de crustacés décapodes ont été identifiées. L’une de celles-ci, Philocheras fasciatus (Risso, 1816), est mentionnée ici pour la première fois des eaux côtières turques de la mer Noire. Les caractéristiques hydrographiques principales telles que la température (intervalle 8,0-21,8°C), la salinité (16,7-17,8h), et l’oxygène dissous (4,5-9,0 mg/l) ont été mesurées à chaque échantillonnage. INTRODUCTION The Black Sea is an inland sea surrounded by land and connected to the Mediterranean through the Turkish Straits System (TSS), and its brackish waters 3) Corresponding author; e-mail: [email protected] © Koninklijke Brill NV, Leiden, 2012 DOI:10.1163/156854012X650278 898 H. BALKIS, A. MÜLAYIM˙ & F. PERÇIN-PAÇAL˙ with a salinity of about 17.6h flow through the Bosporus towards the Sea of Marmara, while Sea of Marmara waters of Mediterranean origin with a salinity of about 38.5h flow towards the Black Sea in a deeper layer (Ünlüata et al., 1990; Yüce & Türker, 1991). There is an intermediate layer of salinity and mixing between 100 and 200 m depth. This sea has a basin of nearly 2 million km2 and a surface area of 423 000 km2. Only the part extending from the surface down to 150 m depth is oxygenated. Below this depth the water contains hydrogen sulfide and almost no oxygen (Bat, 2007; Surugiu, 2010). Due to these factors, the biodiversity of the Black Sea is lower than one third of the biodiversity of the Mediterranean (Zaitsev et al., 2002). Besides, the ecosystem of the Black Sea is currently threatened by pollution, high eutrophication, constructions on the coastal shelf, invasion of alien species as well as excessive and destructive fishing (Öztürk, 1999). The Black Sea is important for Turkish fisheries, as 77.4% of the fishery in the country is carried out here (Gönener & Bilgin, 2006). Therefore, it is necessary to identify the species living in the Black Sea and conduct research on their biological features. Before this study, Holthuis (1961, 1987), Kocata¸s (1981, 1982), Mutlu & Ünsal (1991-1992, 1992), Ate¸s & Sezgin (1998), Öztürk (1999), Ate¸s (1999), Bat et al. (2001), Kocata¸s&Katagan˘ (2003), Bilgin & Çelik (2004), Engin et al. (2004), Gönlügür-Demirci & Katagan˘ (2004), Gönlügür et al. (2004), Kocata¸setal. (2004), Bilgin & Gönlügür-Demirci (2005), Gönlügür-Demirci (2006), Kırkım et al. (2006), Sezgin et al. (2007), Karaçuha et al. (2009) and Ate¸s et al. (2010) have already reported upon the decapod crustaceans in the Turkish waters of the Black Sea. The aim of this study is to determine the decapod crustacean species that live on the Black Sea coasts of Istanbul and to provide information about some of their ecological properties. MATERIAL AND METHODS This research was carried out along the Black Sea coasts of Istanbul between 2000 and 2001. Bottom samples were collected at 36 stations (fig. 1) from depths of 0.5-65 m using a scoop net, dredge, beam-trawl and trammel net. The bottom material was rinsed through sieves with 1 mm mesh size and decapod crustacean specimens were picked out. All specimens were preserved in a 5% formaldehyde solution in sea water. Some ecological parameters of the research area were determined. Temperature was measured using a thermometer on the water sampler, salinity by the Mohr- Knudsen method (Ivanoff, 1972), and dissolved oxygen by the Winkler method.