Mollusca fauna of Iğneada coast (Western Black Sea) and their bioecological features

In the present study the taxonomical and ecological characteristics of the mollusc species distributed along İğneada coasts (Western Black Sea region of Turkey) were determined. For this purpose, samplings were conducted using standard Van-Veen Grab at 9 research stations (at depths 5m, 10m and 20m) between November 2012 and October 2013. As a result of the study, 14 Bivalvia species belonging to 5 orders and 9 families and 26 Gastropoda species belonging to 7 orders and 15 families, consequently with a total, of 37188 individuals belonging to those taxa were identified. Among the families Rissoidae was found to include the highest number of species, followed by Veneridae ( 3 species), Retusidae, Mytilidae, Donacidae, Cardiidae, Trochidae, Pyramidellidae, Hydrobiidae. Nassariidae, Triphoridae ( 2 species), and Corbulidea, Lucinidae, Arcidae, Mactraidae, Tellinidae, Neritidae, Phasianellidae, Pyramidellidae, Calyptraeidae, Caecidae, Muricidae, Epitoniidae, Cerithiidae ( 1 species). Among the 40 identified species, B. reticulatum was found to have the highest dominance value with 21586 specimens (58%), followed by Caecum trachea with 6321 specimens (17%), Lucinella divaricata belonging to Lucinidae with 1859 specimens (5%) and Chamelea gallina with 1610 specimens (4%). For the relative importance of Mollusc species sampled from the study area, frequency index was calculated and 8 species were designated as very common, 11 as common and 24 as rare. The four species with, highest values and very common in the fauna were Bittium reticulatum (100%), Chamelea gallina (97%), Lucinella divaricata (91%) and Cyclope neritea (85%). As a result of the analyses, the highest number of species was found in spring and summer (37 species), followed by autumn (29 species) and winter (28 species).