Bilal Öztürk

Spatio-temporal distributions of zoobenthos in Mersin Bay (Levantine Sea, eastern Mediterranean) and the importance of alien species in benthic communities

Abstract Spatio-temporal variations of soft-bottom zoobenthic communites in Mersin Bay were examined at seven stations between February and October 2009. A total of 337 species were encountered, of which Polychaeta had the highest number of species (136 species), and Mollusca possessed the highest number of individuals (65% of total specimens) and biomass (59% of total biomass). The highest benthos density (max. 9760 ind. m−2) and biomass (max. 133 g m−2) were found at shallow-water stations, whereas the highest diversity index values were calculated at the deepest station. The molluscs Cerithidium diplax, Corbula gibba and Bittium reticulatum dominated the area. Changes of zoobenthic communities were spatial rather than temporal and were strongly correlated with depth and the sediment structures. A total of 40 alien species were found in the area, of which 15 species were possibly transported to the area by ships and the others were Lessepsian migrants. The most domiant alien species in the area were C. diplax, Finella pupoides, Notomastus mossambicus and Amphiodia obtecta. Alien species formed dense populations at shallow water stations, and accounted for 12% of total number of species and 31% of total number of individuals in the area. The community parameters estimated for alien species significantly differed among stations but not among sampling periods. The main factors negatively affecting the number of alien species and individuals were depth, the clay percentage and total organic carbon concentration in sediment. The number of native species and individuals in the area show moderate positive correlations with those of aliens.

On the occurrence of Mytilaster marioni (Locard, 1889) (Mollusca; Bivalvia; Mytilidae) in Bafa Lake (Turkey), with a redescription of the species

In the framework of the study performed in 1997 on the ecological conditions of Bafa Lake and its benthic fauna and flora, a dense population of Mytilaster marioni (Locard, 1889) was observed to have recently colonised the lake. In this study, the ecological changes of the lake induced by a modification of the freshwater inflow, as well as the ecological and taxonomical features of M. marioni, have been investigated. This is the first record of the species from the coastal lakes of the Aegean Sea.

The genus Chrysallida Carpenter, 1856 on the Turkish coasts

Abstract The examination of benthic material collected from different depths and habitats along the Turkish Levantine, Aegean, and Black Sea coasts between the years 1996 and 2010 revealed 19 species of Chrysallida Carpenter, 1856. Among them, Chrysallida palazzii Micali, 1984 is new to the Levantine Sea and Turkish mollusc fauna, C. terebellum (Philippi, 1844) is new to the Turkish Levantine, Aegean and Black Sea coasts, C. dollfusi (Kobelt, 1903) is new to the Turkish Levantine coast, 7 species [C. decussata (Montagu, 1803), C. flexuosa (Monterosato, 1874), C. incerta (Milaschewitsch, 1916), C. indistincta (Montagu, 1808), C. intermixta (Monterosato, 1884), C. jeffreysiana (Monterosato, 1874), and C. suturalis (Philippi, 1844)] are new reports for the Turkish Aegean coast, and C. fenestrata (Jeffreys, 1848) is new for the Turkish coast of the Black Sea. Two species [C. maiae (Hornung & Mermod, 1924) and C. micronana Öztürk & Aartsen, 2006] are alien species that entered the Mediterranean in last three decades. The identified species, apart from C. obtusa (Brown, 1827) and C. flexuosa, were found to be distributed at depth ranges from 0 to 100 m. The last two species were from deeper waters. C. obtusa was found to have a wide depth range from 5 m to 875 m, whereas C. flexuosa was significant as the deepest species, found at 875 m. Some ecological characteristics and taxonomic remarks, with distribution features of the identified species along the Turkish coasts, are also provided.

Polyplacophora (Mollusca) from the Aegean coast of Turkey

Abstract This study has been conducted in order to determine the Polyplacophoran species occurring along the Aegean coasts of Turkey. As a result of collecting carried out in different habitats at 21 selected locations, 11 species were identified: Lepidopleurus cajetanus, L. scabridus, Ischnochiton rissoi, Callochiton septemvalvis euplaeae, Lepidochitona cinerea, L. corrugata, L. monterosatoi, Chiton corallinus, Ch. olivaceus, Acanthochitona crinita, and A. fascicularis. Of these species, Lepidopleurus scabridus is reported for the first time from Turkey, and Chiton corallinus is new for the Aegean fauna of Turkey.

Macrobenthic fauna associated with the invasive alien species Brachidontes pharaonis (Mollusca: Bivalvia) in the Levantine Sea (Turkey)

The invasive alien mytilid species, Brachidontes pharaonis , forms a biogenic habitat in the mediolittoral and upper-infralittoral zones of the Levantine Sea, hosting a number of alien and native species. Examinations of samples taken from dense, continuous mussel beds at seven stations along the coast of northern Levantine Sea yielded 187 macro-benthic invertebrate species belonging to 11 taxonomic groups. Polychaeta accounted for 46% and 37% of the total number of species and individuals, respectively. The top three dominant species in the mussel beds were Stenothoe gallensis, Spirobranchus kraussi and Mytilaster minimus . The species with the highest frequency values on the mussel beds were Pseudonereis anomala, Phascolosoma stephensoni and Elasmopus pocillimanus . The highest density and biomass of the associated fauna were estimated as 42,550 ind m −2 and 1503 wwt g m −2 , respectively. The species number in samples varied between 14 and 47 species. The environmental variables best explaining variations in zoobenthic community structures were salinity, dissolved oxygen and total inorganic nitrogen in the water column. The biotic indices, TUBI and ALEX, classified the ecological status of one or two stations as moderate or poor, based on the relative abundances of ecological and zoogeographic groups, respectively. A total of 21 alien species were found to be associated with the mussel bed, of which Syllis ergeni is being newly considered as a new established alien species for the Mediterranean Sea. The maximum density of associated alien species was calculated as 30,300 ind m −2 . The alien species assemblages were greatly affected by salinity and total inorganic nitrogen.

On the presence of Pandora inaequivalvis (Bivalvia: Pandoridae) on the Levantine coast of Turkey

In a benthic study conducted in Iskenderun Bay, Turkey, in July 2007, the pandorid bivalve Pandora inaequivalvis was encountered at four stations having depths of 1.5–7.5 metres and muddy sand bottoms. This is the first record of this species for the Turkish part of the Levantine Sea.

Macrozoobenthic community structure of İğneada region in Turkey (the southwestern Black Sea)

Abstract The present study deals with macrozoobenthic species on soft substrates in İğneada (Turkish coast of the Black Sea). Benthic samples were collected seasonally at three stations between 2012 and 2013. A total of 155 species belonging to seven taxa (Turbellaria, Nemertea, Nematoda, Oligochaeta, Polychaeta, Crustacea, Phoronida, Mollusca, Hemichordata) were identified. Of these, four species are new records for the Black Sea fauna, 15 species are new to the Turkish coast of the Black Sea; and two species are new to the Turkish Seas. Polychaeta was the most representative taxon in the study area – it was represented by 58 species (39% of the total number of species). In terms of the number of individuals, Mollusca were the dominant taxon in all seasons (82% of the total number of individuals). The most dominant species were Bittium reticulatum and Caecum trachea and the most frequent species were Micronephtys stammeri, B. reticulatum and Chamelea gallina.

Temporal variation of the soft-bottom molluscan fauna in north-western İskenderun Bay (Levantine Sea)

Abstract The present study was performed to follow temporal variation of the soft-bottom molluscan fauna in north-western Iskenderun Bay. The benthic material was collected at a depth ranging from 3 to 37 m at 12 sampling locations by the van Veen grab sampler in the summer season of 2012, 2013 and 2014. A total of 133 species were identified in the study area through the examination of the collected material. Among the identified species, Corbula gibba (Olivi, 1792), Bittium reticulatum (da Costa, 1778), Nassarius pygmaeus (Lamarck, 1822), Cerithidium diplax (Watson, 1886) and Finella pupoides Adams, A., 1860 have the highest values of the frequency index. According to the Bray-Curtis similarity index, these species also have an important effect on the similarity between the stations. Furthermore, C. diplax and F. pupoides are alien species to the Mediterranean.