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Öğe Amathillina cristata Sars 1894, a Ponto-Caspian amphipod genus newly recorded from Turkey (Amphipoda: Gammaridae)(Max Kasparek Verlag, 2010) Ozbek, Murat; Ozkan, NurcanÖğe Amathillina cristata Sars 1894, a Ponto-Caspian amphipod genus newly recorded from Turkey (Amphipoda: Gammaridae)(Max Kasparek Verlag, 2010) Ozbek, Murat; Ozkan, NurcanÖğe Aspects of biology of the deep-water pandalid shrimp Plesionika martia (A. Milne-Edwards, 1883) from Sigacik Bay (eastern Mediterranean)(Tubitak Scientific & Technical Research Council Turkey, 2012) Kocak, Cengiz; Ozbek, Murat; Tosunoglu, ZaferSome aspects concerning the reproduction, growth, and population dynamics of Plesionika martia were studied. Individuals were collected monthly between May 2008 and April 2009 during surveys conducted using a commercial trawl vessel. Samples were collected from Sigacik Bay (Aegean Sea, eastern Mediterranean) at depths ranging from 494 to 550 m. A total of 2110 individuals (766 males and 1344 females) were caught during these monthly surveys. The carapace length (Cl,) of the males ranged from 12.4 to 22.1 mm, and in females the CL ranged between 11.5 and 24.9 mm. The values of both CL and weight in females consistently exceeded that of males throughout the year. Although ovigerous females were observed throughout the year, the main reproductive period is suggested to be from May to December. In all groups examined, the values of allometric coefficient b were less than 3. Estimates of the Von Bertalanffy growth parameters were L-Y = 26.25 mm and k = 0.38 year(-1) in females, and L-Y = 23.63 mm and k = 0.49 year(-1) in males.Öğe Assessing the Trophic Level of a Mediterranean Stream (Nif Stream, Izmir) Using Benthic Macro-Invertebrates and Environmental Variables(Central Fisheries Research Inst, 2019) Ozbek, Murat; Tasdemir, Ayse; Cil, Eylem Aydemir; Somek, Hasim; Yildiz, SerayThe study was conducted in Nif Stream (Izmir) and the aims of the study are (a) to determine the benthic macro-invertebrate composition of the stream, (b) to determine environmental features of the stream, (c) to investigate the relations between the determined species and the environmental variables and (d) to assess the trophic level of the stream which was under the pressure of industry, agriculture and settlement. Samplings of macrobenthic invertebrates were performed seasonally at eight stations between October 2013 and September 2014 in addition to measuring environmental variables of the localities. 11571 specimens were investigated and totally 77 taxa were determined. Chironomidae and Oligochaeta were the higher groups in terms of species richness with 25 and 17 species, respectively. Multivariate analyses indicate that pH, Ca2+ and NO3-N were the most effective variables and explained 48.6% of the variance in the distribution and abundance of benthic macroinvertebrates in Nif Stream. Along the measured physicochemical characteristics and scores of biological indices, the upper branches of the stream have good quality water while the middle and lower parts are heavily polluted.Öğe Assessment of a Shallow Montane Lentic Ecosystem (Lake Golcuk, Izmir, Turkey) Using Benthic Community Diversity(Foundation Environmental Protection & Research-Fepr, 2015) Yildiz, Seray; Ozbek, Murat; Tasdemir, Ayse; Topkara, Esat TarikThe macrobenthic invertebrate community of a shallow Mediterranean lake (Lake Golcuk, Izmir, Turkey) was studied in order to (a) describe the intra-annual and spatial variability in benthic communities, (b) relate possible community changes to environmental conditions and (c) evaluate the responses of the lake's ecological status on community indices. The benthic assemblage was sampled seasonally at six sites during a period of 2 years (June 2008-March 2010). Additionally, hypolimnetic water quality variables were monitored over the same period at each site. The benthic fauna of Lake Golcuk was found to be very limited with 16 species belonging to four taxonomic groups. Potamothrix hammoniensis was the dominant benthic species and represented more than 72% of the total benthic fauna. Depth, dissolved oxygen, pH, conductivity, transparency, and water temperature seemed to be the main environmental factors affecting community indices. Benthic communities are affected by human disturbances in Lake Golcuk shifting their composition to more tolerant taxa, reflecting also the eutrophic to hypertophic character of the lake.Öğe Determination of Pollution Level of Yuvarlak Stream (Koycegiz-Mugla) by Using Benthic Macro Invertebrates(Medwell Online, 2011) Topkara, E. Tarik; Ozbek, Murat; Tasdemir, Ayse; Yildiz, Seray; Balik, Suleyman; Ustaoglu, M. RusenIn order to determine the pollution level of Yuvarlak stream by using benthic macro invertebrates, monthly samplings were conducted between May 2001 and April 2002 at ten stations. Benthic macro invertebrates were sampled by sieving of mud samples collected by using a 500 pm mesh sized kick-net and an Ekman-Birge grab (at ninth and tenth stations) through a 500 pm mesh sized sieve. Collected materials were fixed in 4% formalin solution in field.Öğe Dikerogammarus istanbulensis sp. n., a new amphipod species (Amphipoda: Gammaridae) from Turkey with a key for the genus(Magnolia Press, 2011) Ozbek, Murat; Ozkan, NurcanA new amphipod species, Dikerogammarus istanbulensis sp. nov., is described. Specimens were collected from a reservoir, near Silivri district, Istanbul province, Turkey. The new species is similar to Dikerogammarus bispinosus Martynov, 1925 except for the presence of setae on inner surface of basal segment of pereopod 7 in both sexes and absence of long setae on the ventral side of second peduncle segment of antenna 1. In addition, epimeral plate 2 has many setae along the ventral margin in both sexes. A detailed morphological description and illustrations of the new species are given. Differences between the new species and related species are discussed. An identification key for the genus Dikerogammarus is presented.Öğe Distribution of aquatic oligochaetes (Annelida, Clitellata) of high-elevation lakes in the Eastern Black Sea Range of Turkey(Tubitak Scientific & Technical Research Council Turkey, 2012) Yildiz, Seray; Ozbek, Murat; Ustaoglu, Mustafa Rusen; Somek, HasimMany large and small lakes of varying depths are present in the Eastern Black Sea Range of Turkey, the nation's third most important glacial region following the Agri and Cilo-Sat mountain ranges. During the present study, 6 expeditions to collect aquatic oligochaetes from these lakes were conducted in July and August of 2005, 2006, and 2007; qualitative and quantitative samples were collected from 59 glacial lakes. We present and analyze the dominancy and distribution of aquatic oligochaete assemblages and their relation to environmental factors (temperature, dissolved oxygen, pH, electrical conductivity, salinity, turbidity, PO4-3-P, HCO3-, organic carbon, hardness, Ca2+, Mg2+, Si, water depth, and altitude) using classification and ordination techniques. Canonical correspondence analysis (CCA) was used to characterize the relationship between oligochaetes and the environmental variables. As a result, we determined the 4 most important environmental variables (elevation, water depth, dissolved oxygen, and temperature) affecting species distribution in general. Sampling localities were clustered into 8 groups with the unweighted pair-group method with arithmetic mean (UPGMA) based on physicochemical characteristics. The relationships between the total number of individuals and environmental measurements were determined by a simple analysis of variance (ANOVA) test. The results of our analyses suggest a significant positive correlation between altitude (P < 0.05; F = 2.994) and the total number of individuals.Öğe Diversity of benthic macroinvertebrates and water quality of Karasu Stream (Black Sea)(Ege Univ, Fac Fisheries, 2021) Cil, Eylem Aydemir; Ozbek, Murat; Yardim, Oztekin; Yildiz, Seray; Tasdemir, Ayse; Rasouli, Hamidreza; Gurbuzer, PinarThe study was conducted in Karasu Stream (Sinop Province, Black Sea Region of Turkey). The purpose of this study is, to determine the benthic macroinvertebrate composition of the stream, together with some of its environmental characteristics (water temperature, pH and dissolved oxygen) to evaluate the trophic level of the stream. Samplings of benthic macroinvertebrates and environmental variables were performed monthly at ten stations between February 2013 and January 2014. As a result, 18260 specimens were investigated and 175 taxa were determined. Chironomidae and Oligochaeta were the higher groups in terms of species richness with 48 and 38 taxa, respectively. The BMWP and ASPT indices indicate that all the stations belong to slightly polluted (Class II) or unpolluted (Class I) water quality levels.Öğe Echinogammarus Baliki sp nov., a new species of amphipod from Turkey (Amphipoda, Gammaridae)(Brill Academic Publishers, 2007) Ozbek, Murat; Ustaoglu, M. RusenEchinogammarus baliki sp. nov., a new species of gammarid amphipod, is described and illustrated based on samples collected from Lake Akgol, near Selcuk, Izmir province, Turkey. A detailed morphological description and illustrations of the new species are given. Differences between the new species and related species are discussed.Öğe Epigean amphipod fauna of Gonen Stream (western Anatolia, Turkey), with the description of Gammarus gonensis sp nov.(Tubitak Scientific & Technical Research Council Turkey, 2016) Ozbek, MuratGonen Stream, which is about 134 km in length, arises from the Ida Mountains near Balikesir and flows out near Misakca to the Sea of Marmara. In order to determine the freshwater amphipod species of Gonen Stream, 8 seasonal samplings were conducted between June 2010 and June 2012. Samplings were made at 16 stations located between the upper and lower parts of the stream. As a result of the study, 3 amphipod species were found, one of which is new to science: Gammarus gonensis sp. nov. The newly described species belongs to the Gammarus pulex- group. Gammarus gonensis resembles G. uludagi G. Karaman, 1975 by having long curled setae on the second gnathopods of the males. It differs from G. uludagi by having many long setae along the anterior margins of pereopods 5 to 7 in both sexes, and by having less setose peduncular segments of antenna 2. Some other characteristic features of the newly described species are also discussed, and detailed drawings of the extremities of holotype and allotype specimens are presented.Öğe First record of Spongilla lacustris (Porifera: Demospongiae) from the Eastern Black Sea (Uzungol Lake, Trabzon)(Ege Univ, 2017) Ozbek, Murat; Uluturk, EfeIn order to determine the benthic macro-invertebrate fauna of Uzungol Lake (Trabzon), colonies of the freshwater sponge (Spongilla lacustris L., 1759) were observed during the field study. The sponge colonies were sampled by standard macrophyte sampling equipment (rake) from the bottom of the lake (2 meters depth). This record is the first one of the species for Uzungol Lake and for the Eastern Black Sea Region.Öğe First records of two formerly overlooked Ponto-Caspian amphipods from Turkey: Echinogammarus trichiatus (Martynov, 1932) and Dikerogammarus villosus (Sovinsky, 1894)(Tubitak Scientific & Technical Research Council Turkey, 2016) Rewicz, Tomasz; Konopacka, Alicja; Bacela-Spychalska, Karolina; Ozbek, Murat; Grabowski, MichalTo date, 13 species of Ponto-Caspian amphipods have been reported from the inland waters of Turkey. Two, probably overlooked species, Echinogammarus trichiatus and Dikerogammarus villosus, are here recorded for the first time from this country. Due to the atypical morphology, the identity of E. trichiatus was also verified with molecular methods, based on the mtDNA COI barcode. Both species, along with five other co-occurring Ponto-Caspian amphipods, were collected from Lake Durusu in September 2007. Our finding reveals high diversity of amphipods in this water body. It also presents the southernmost known localities of both species, and expands the checklist of Ponto-Caspian amphipod fauna of Turkey to 15 species. Taking into account the geographical range of both species, we may conclude that they are native to Lake Durusu and their presence there was previously overlooked.Öğe Freshwater Amphipod Species of Western Anatolia, Marmara and Turkish Thrace Regions(Istanbul Univ Press, Fac Aquatic Sciences, 2022) Ipek, Mehmet; Ozbek, MuratTo determine the Amphipoda (Crustacea) fauna of the inland waters of Western Anatolia, Marmara and the Turkish Thrace Region, field studies were conducted between May 2014 and March 2019. Seven field studies were conducted. Samplings were conducted at 291 localities and amphipod specimens were found at 127 of them. As a result, 11 amphipod species (Echinogammarus stocki G. Karaman, 1970, Gammarus aequicauda (G. Karaman, 1970), Gammarus anatoliensis Schellenberg, 1937, Gammarus arduus G. Karaman, 1975, Gammarus balcanicus Schaferna, 1923, Gammarus dorsosetosus Mateus & Mateus, 1990, Gammarus gonensis Ozbek, 2016, Gammarus komareki Schaferna, 1923, Gammarus lacustris G.O. Sars, 1863, Gammarus pulex pulex (Linnaeus, 1758), Gammarus uludagi G.S. Karaman, 1975) were determined. The new records can be listed as: E. stocki for Ekinanbari, G. anatoliensis for Usak, G. arduus for Bolu and Duzce, G. balcanicus for Kocaeli and Sakarya, G. dorsosetosus for Bolu, G. gonensis for Istanbul and Manisa, G. komareki for Duzce and Kocaeli, G. lacustris for Istanbul, G. pulex pulex for Bolu, Kirklareli, Kocaeli, Sakarya and Usak, and G. uludagi for Aydin, Bilecik, Sakarya and Yalova provinces. The observed morphological features and the detailed drawings of the determined taxa are presented. Additionally, a map showing the distribution of the obtained species is also given.Öğe Freshwater and Brackish Amphipods (Crustacea: Amphipoda) from Turkish Thrace Region (Including Canakkale Province)(Inst Zoology, Bas, 2017) Ozbek, Murat; Ozkan, Nurcan; Camur-Elipek, BelginIn order to determine the fresh and brackish water amphipod species of the Turkish Thrace Region, specimens were sampled from 68 localities in Istanbul, Edirne, Tekirdag, Kirklareli and canakkale Provinces. Totally, 16 amphipod taxa were identified: Gammarus arduus G. Karaman, 1975, G. komareki Schaferna, 1922, G. pulex pulex (L., 1758), G. fossarum Koch, 1836, G. balcanicus Schaferna, 1922, G. aequicauda (Martynov, 1931), G. subtypicus Stock, 1966, G. uludagi Karaman, 1975, G. gonensis Ozbek, 2016, G. kesanensis Ozbek & camur-Elipek, 2010, Dikerogammarus istanbulensis Ozbek & Ozkan, 2011, Amathillina cristata Sars, 1894, Orchestia cavimana Heller, 1865, Synurella ambulans F. MOLLER, 1846, Pontogammarus robustoides Sars, 1894 and Niphargus sp. All the determined species were previously recorded-from Turkey. This is the first record of Gammarus gonensis in Europe. Information about the sampling localities and a distribution map of the species are presented.Öğe Gammarus baysali sp nov., a new freshwater amphipod species from Turkey (Amphipoda: Gammaridae)(Tubitak Scientific & Technical Research Council Turkey, 2013) Ozbek, Murat; Yurga, Levent; Kulkoyluoglu, OkanA new species of freshwater amphipod, Gammarus baysali sp. nov., collected from Cumayani Cave (Zonguldak Province, Turkey) is described and illustrated. The new species belongs to the Gammarus pulex-group. The most discriminant characters of this species are the minute eyes, densely setose fifth peduncle and flagellar segments of antenna 2, elongated pereopods, and setose anterior margins of pereopod 5 to 7. Additionally, the palp of right maxilla 1 has 4 setae along its outer margin. A detailed morphological description and illustrations of the new species are provided, and differences from related species are discussed.Öğe Gammarus baysali sp nov., a new freshwater amphipod species from Turkey (Amphipoda: Gammaridae)(Tubitak Scientific & Technical Research Council Turkey, 2013) Ozbek, Murat; Yurga, Levent; Kulkoyluoglu, OkanA new species of freshwater amphipod, Gammarus baysali sp. nov., collected from Cumayani Cave (Zonguldak Province, Turkey) is described and illustrated. The new species belongs to the Gammarus pulex-group. The most discriminant characters of this species are the minute eyes, densely setose fifth peduncle and flagellar segments of antenna 2, elongated pereopods, and setose anterior margins of pereopod 5 to 7. Additionally, the palp of right maxilla 1 has 4 setae along its outer margin. A detailed morphological description and illustrations of the new species are provided, and differences from related species are discussed.Öğe Gammarus izmirensis sp nov., a new species of freshwater amphipod from Turkey (Amphipoda, Gammaridae)(Brill Academic Publishers, 2007) Ozbek, MuratA new species of freshwater amphipod, Gammarus izmirensis sp. nov., belonging to the Gammarus pulex-group, is described. Specimens have been collected from a stream in the Kemalpasa district, Izmir province, western Anatolia. A detailed morphological description and illustrations of the new species are given. Differences between the new species and related species are discussed.Öğe Gammarus kesanensis sp nov., a new blind amphipod species from Turkey (Amphipoda, Gammaridae), with a key to eyeless Gammarus species of Europe(Magnolia Press, 2010) Ozbek, Murat; Camur-Elipek, BelginA new blind species of freshwater amphipod, Gammarus kesanensis sp. nov., collected from Erikli Fountain, Kesan, Turkey, is described and illustrated. The new species belongs to Gammarus pulex- group and is the fourth blind species of the group reported from Europe and Turkey. A detailed morphological description and illustrations of the new species are given and differences from related species are discussed. In addition, a key to the blind/eyeless species of Gammarus genus of Europe is presented.Öğe Gammarus komareki aznavensis subsp nov., a new amphipod subspecies from Iran (Amphipoda: Gammaridae)(Tubitak Scientific & Technical Research Council Turkey, 2014) Ozbek, Murat; Rasouli, HamidrezaA new subspecies of freshwater amphipod, Gammarus komareki aznavensis subsp. nov., collected from Aznav County (Khalkhal-Ardabil), northwestern Iran, is described and illustrated. The new subspecies belongs to the Gammarus pulex-group and has characteristic features similar to Gammarus komareki. Shorter flagellum of antenna 1, kidney-shaped and bigger eyes, more setose outer margin of the exopodite of uropod 3, and shorter endopodite of uropod 3 are the most obvious features that differ from G. komareki. A detailed morphological description and illustrations of the new subspecies are given and differences from related species are discussed.
