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Öğe Age, length-weight relationships and diet composition of scaldfish Arnoglossus laterna (Walbaum, 1792) (Pisces: Bothidae) in Izmir Bay (Aegean Sea)(2008) Bayhan B.; Sever T.M.; Taskavak E.The age, length-weight relationship and diet composition of Arnoglossus laterna from the Izmir Bay were examined in specimens caught on a seasonal basis from January 2002 to March 2003. The ratio of male to female of 1081 scaldfish captured by trawl netting was 1:1.62 and their total lengths varied from 5.6-15.7 cm and total weights from 1.2-31.51 g. The length-weight relationships were estimated as W = 0.0035 L3.301; W = 0.0066 L3.043; W = 0.0073 L3.011 for females, for males and for all individuals, respectively. Based on the otolith readings, the age distribution of the samples varied from I to V years. The von Bertalanffy growth parameters were calculated to be L? = 16.87 cm, k = 0.236 year-1, t 0 = -0.887 year. Stomach contents of A. laterna were filled with preys of 5 major taxonomical groups: Polychaeta, Crustacea, Mollusca, Chaetognatha and Teleostei. A total of 11 prey groups were identified in the diets of scaldfish with most abundant crustaceans. According to a Bray-Curtis similarity index in relation to ages, two groups are formed based on index percentage of relative importance of food item; I-II age groups constituted the first similarity and III-IV-V the second one. © Medwell Journals, 2008.Öğe Food habits of the hollowsnout grenadier, Caelorinchus caelorhincus (Risso, 1810), in the Aegean Sea, Turkey(2008) Sever T.M.; Filiz H.; Bayhan B.; Taskavak E.; Bilge G.Stomach contents of 148 hollowsnout grenadier, Caelorinchus caelorhincus (RISSO, 1810), were examined. Crustaceans were found to be most important prey group in the diet. Polychaetes constituted the second most important prey group. Chaetognathans were only occasionally eaten.Öğe Length-weight relationships for 47 fish species from Izmir Bay (eastern Aegean Sea, Turkey)(2006) Özaydin O.; Taskavak E.Length-weight relationships were calculated for 47 fish species from the Izmir Bay in the Aegean Sea, Turkey. A total of 13243 fish specimens were sampled with several fishing gears in 1998-2001. The sample size ranged from 11 individuals for Nerophis ophidion to 1197 for Boops boops. The r2 values ranged from 0.82 for Nerophis ophidion to 0.99 for Scorpaena scrofa, and all regressions were highly significant (p<0.001). Values of the exponent b in the length-weight regression (W = aLb) ranged 1.970-3.727. The median was 3.042 and over 50% of the values were within 2.9373.186. Information from the present survey may be used for fisheries management or other practical purposes.Öğe A morphometric approach to sexual dimorphism of black-striped pipefish syngnathus abaster in lake bafa (Mugla-Turkey)(Parlar Scientific Publications, 2020) Gurkan S.; Taskavak E.; Innal D.This study aims to determine the presence of sexual dimorphism based on morphometric characteristics in 69 (female: 44 male: 25) Syngnathus abaster specimens captured with seine-net from Lake Bafa's coasts (Mugla) between November 2014 and March 2016. Female/Male ratio of samples is 1/0.6. Based on morphometric measurements, the presence of sexual dimorphism was determined in among specimens pooled according to total length groups (I: 50-74 mm; II: 75-99 mm; III: 100-124mm IV: 125mm>). Thus, a statistical difference (p <0.05) is present between sexes in terms of body height (BH). Total length of males having a positive allometric growth is greater than that of female specimens, whereas females are higher than males. According to size groups, statistical sexual differences (p <0.05) were observed among length groups II and III of females and length group I of males. In conclusion, the species Syngnathus abaster, which is included in the Least Concern (LC) category of IUCN Red List, appears to have sexual dimorphism in the Lake Bafa's coasts in terms of body height. © by PSP.Öğe Range extension of three lessepsian migrant fish (Fistularia commersoni, Sphyraena flavicauda, Lagocephalus suezensis) in the Mediterranean Sea(2002) Bilecenoglu M.; Taskavak E.; Kunt K.B.Two Red Sea immigrant fish species, Fistularia commersoni (Fistularidae) and Sphyraena flavicauda (Sphyraenidae), are reported for the first time from the Anatolian coast (Turkey) and for the second time from the Mediterranean Sea. Occurrence of Lagocephalus suezensis (Tetraodontidae) at the southern Turkish coast is substantiated and a new record of this species in the Aegean Sea is presented.Öğe Seasonal food composition and prey-length relationship of pipefish Nerophis ophidion (Linnaeus, 1758) Inhabiting the Aegean Sea [Sezonski sastav hrane i odnos plijen-duzina kod šila nerophis ophidion iz egejskog mora](2011) Gurkan S.; Sever T.M.; Taskavak E.This study examined the gut content of 43 Nerophis ophidion individuals obtained from Izmir Bay, Eastern Aegean Sea. A four season sampling process provided 7 groups of prey: Ostracoda, Amphipoda, Gastropoda, Cirripedia, Decapod crustacea, bentic Cinideria and Copepoda (Calanoid, Harpacticoid, Cyclopoid-Sapphirina sp., E. acutifrons and Monstrilloid) Harpacticoid copepod, Cyclopoid copepod Cypris larvae and Ostracoda. Only 4 stomachs were empty. Gastropoda (9.47%), Amphipoda (37.22%) and Harpacticoid copepod (1.77%) are considered as dominant prey in the food composition of N.ophidion. On the other hand, Harpacticoid and Cyclopoid copepods are found in almost all sampling periods, and thus they are considered as major prey. Amphipoda was the most predominant prey in both spring (24.39%) and summer (12.82%), and Gastropoda (6.32%) in autumn. The presence of Harpacticoid copepods consumed by almost all lengths of fish indicates that their intake by pipefish derives from bentic vegetation rather than the water column. The ability to consume larger prey may be correlated with fish size. In our study, while larger Nerophis ophidion had an intake of relatively larger prey, they continued to catch smaller prey items as well. This result may imply that the bigger the fish in size, the more prey groups they could catch.Öğe A serological investigation of the bufo bufo (anura, bufonidae) populations in southern marmara (manyas, bahkesir) and eastern black sea (Çamhhemşin, rize) regions(2001) Tosunoğlu M.; Taskavak E.Conventional taxonomic treatment has resulted in uncertainty as to the taxonomic status of the two subspecies Bufo bufo spino sus and B. b. verrucosissimus in Turkey. Blood-serum proteins of the B. bufo specimens from Manyas and Çamhhemşin were com pared qualitatively and quantitatively by polyacrylamide-disc elec-trophoresis and densitometry. The Authors found no significant differences between the blood-serum proteins of the two popula tions examined, and therefore recommend that B. b. verrucosis simus be synonymized with B. b. spinosus. © 2001 Taylor & Francis Group, LLC.Öğe Some investigations on the taxonomic status of Emys orbicularis from the Aegean and Central Anatolian regions of Turkey(2006) Taskavak E.; Ayaz D.A total of 219 Emys orbicularis specimens collected at 7 localities featuring different ecological and geographical characteristics in western and central Anatolia were examined. We compared 25 different ratios to investigate the morphological differences and similarities among populations. Male-female sex ratios and growth parameters (W = aLb) were also considered. A discriminant analysis based on these 14 morphometric characters and 25 ratios clearly confirmed the differences between the E. orbicularis specimens from the Aegean and Central Anatolian regions. Considering differences in morphological characters found in both discriminant analyses and pair-wise comparison, we assume that the Boget specimens, an isolated population, are not an intermediate form between E. o. cf. hellenica in coastal areas of the Aegean region and Emys orbicularis luteofusca, from Eregli (Konya) in Central Anatolia. The Boget specimens also differentiate statistically from those in Mogan (about 180 km north of Boget) and Kayseri (about 230 km east of Boget). © 2006 Asian Network for Scientific Information.
