Dužinsko-maseni odnos 47 ribljih vrsta iz Izmirskog zaljeva (istočni dio Egejskog mora, Turska)

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 2.937- 3.186. Information from the present survey may be used for fisheries management or other practical purposes.Istraživan je dužinsko-maseni odnos za 47 vrsta u Egejskom moru (Izmirski zaljev). Ukupno je obrađeno 13243 jedinki uzorkovanim s nekoliko različitih ribarstvenih alata u razdoblju od 1998. do 2001. godine. Broj jedinki kolebao je od 11 za šilce gretenkljuno Nerophis ophidian do 1197 za bukvu, Boops boops. Vrijednosti koeficijenta determinacije r2 su kolebale u rasponu od 0.82 za šilce gretenkljuno N. ophidian do 0.99 za škrpinu, Scorpaena scrofa, dok su regresije bile statistički vrlo značajne (P<0.001). Vrijednosti eksponenata b kod dužinsko-masenih odnosa (W = aLb) su kolebale između 1.970-3.727. Srednja vrijednost je iznosila 3.042, dok se 50% svih vrijednosti kretalo u rasponu između 2.937 i 3.186. Dobiveni podatci iz ove studije mogu poslužiti svsishodno za potrebe gospodarenja ribljim bogatstvima kao i za neke druge praktične primjene

Dužinsko-maseni odnos 47 ribljih vrsta iz Izmirskog zaljeva (istočni dio Egejskog mora, Turska)

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 2.937- 3.186. Information from the present survey may be used for fisheries management or other practical purposes.Istraživan je dužinsko-maseni odnos za 47 vrsta u Egejskom moru (Izmirski zaljev). Ukupno je obrađeno 13243 jedinki uzorkovanim s nekoliko različitih ribarstvenih alata u razdoblju od 1998. do 2001. godine. Broj jedinki kolebao je od 11 za šilce gretenkljuno Nerophis ophidian do 1197 za bukvu, Boops boops. Vrijednosti koeficijenta determinacije r2 su kolebale u rasponu od 0.82 za šilce gretenkljuno N. ophidian do 0.99 za škrpinu, Scorpaena scrofa, dok su regresije bile statistički vrlo značajne (P<0.001). Vrijednosti eksponenata b kod dužinsko-masenih odnosa (W = aLb) su kolebale između 1.970-3.727. Srednja vrijednost je iznosila 3.042, dok se 50% svih vrijednosti kretalo u rasponu između 2.937 i 3.186. Dobiveni podatci iz ove studije mogu poslužiti svsishodno za potrebe gospodarenja ribljim bogatstvima kao i za neke druge praktične primjene

Sezonski sastav hrane i odnos plijen-dužina kod šila Nerophis ophidion iz Egejskog mora

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.U ovoj studiji su pregledana 43 želudca jedinki vrste Nerophis ophidion ulovljenih u Izmirskom zaljevu, istočni dio Egejskog mora. Nakon razdoblja jedne godine uzorkovanja (sve četiri sezone) utvrđeno je sedam grupa plijena: Ostracoda, Amphipoda, Gastropoda, Cirripedia, Decapoda, bentoski oblici Cnidaria i Copepoda (veslonošci) (Calanoid, Harpaticoid, Cyclopoid-Sapphirina sp., E. acutifrons i Monstrilloid), harpatikoidni kopepodi, cyclopodni veslonožac Cypris ličinke i Ostracoda. Samo su četiri želudca bila prazna. Gastropoda (9.47%), Amphipoda (37.22%) i harpatikoidni kopepodi (1.77%) su prevladavajući plijen vrste N. ophidion. S druge strane, Harpatikoidi i ciklopodini kopepodi su utvrđeni u gotovo svim razdobljima uzorkovanja i stoga se ubrajaju u glavni plijen. Amphipoda su najdominantniji piljen tijekom proljeća (24.39%) i ljeta (12.82%), a Gastropda (6.32%) tijekom jeseni. Nazočnost harpatikodinih kopepoda u svim dužinskim klasama ukazuje da njihova konzumacija vjerojatnije potiče sa bentoske vegetacije u odnosu na vodeni stupac. Mogućnost konzumacije većeg plijena je u korelaciji sa duljinom ribe. U ovoj studiji, veće jedinke uglavnom konzumiraju krupniji plijen no ne prestaju konzumirati i znatno sitniji plijen. Ovo može ukazivati i na to da što je veći grabežljivac to je njegova mogućnost ulova i konzumacije većeg broja različitih grupa plijena veća

Sezonski sastav hrane i odnos plijen-dužina kod šila Nerophis ophidion iz Egejskog mora

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.U ovoj studiji su pregledana 43 želudca jedinki vrste Nerophis ophidion ulovljenih u Izmirskom zaljevu, istočni dio Egejskog mora. Nakon razdoblja jedne godine uzorkovanja (sve četiri sezone) utvrđeno je sedam grupa plijena: Ostracoda, Amphipoda, Gastropoda, Cirripedia, Decapoda, bentoski oblici Cnidaria i Copepoda (veslonošci) (Calanoid, Harpaticoid, Cyclopoid-Sapphirina sp., E. acutifrons i Monstrilloid), harpatikoidni kopepodi, cyclopodni veslonožac Cypris ličinke i Ostracoda. Samo su četiri želudca bila prazna. Gastropoda (9.47%), Amphipoda (37.22%) i harpatikoidni kopepodi (1.77%) su prevladavajući plijen vrste N. ophidion. S druge strane, Harpatikoidi i ciklopodini kopepodi su utvrđeni u gotovo svim razdobljima uzorkovanja i stoga se ubrajaju u glavni plijen. Amphipoda su najdominantniji piljen tijekom proljeća (24.39%) i ljeta (12.82%), a Gastropda (6.32%) tijekom jeseni. Nazočnost harpatikodinih kopepoda u svim dužinskim klasama ukazuje da njihova konzumacija vjerojatnije potiče sa bentoske vegetacije u odnosu na vodeni stupac. Mogućnost konzumacije većeg plijena je u korelaciji sa duljinom ribe. U ovoj studiji, veće jedinke uglavnom konzumiraju krupniji plijen no ne prestaju konzumirati i znatno sitniji plijen. Ovo može ukazivati i na to da što je veći grabežljivac to je njegova mogućnost ulova i konzumacije većeg broja različitih grupa plijena veća

A Preliminary Study on the Determination of Reproductive Biology of European Pilchard, Sardina pilchardus (Walbaum, 1792) Distributed in the Aegean Sea

Sardina pilchardus is a multiple spawning fish, i.e., the species that spawns periodically during the spawning period. in order to examine the reproduction biology of the species, the specimens were obtained in the known spawning period indicated by the current literature obtained from fishers who were commercially fishing in December 2018 and January-February 2019. After the fork length and total length together with their weight measurements, the specimens were dissected in the laboratory. the adult females’ gonads were then fixed in 4% formalin solution for fecundity. A total of 170 individuals was examined and the values of their fork length, total length and weight were computed as 9.7-13.4 cm (mean: 11.16±0.81), 10.5-15 cm (mean: 12.3±0.89), 8.06-23.7 g (mean: 12.7±2.93), respectively. 44 of the supplied specimens were male (25.9%), 122 female (71.8%) and 4 (2.3%) uncertain, thus, the female: male ratio was determined as 2.77:1. According to ?2 test results, a statistically significant difference was observed among individuals. For the specimens examined, the fork length-weight relationship was calculated as W = 0.0098FL2.96, while total length-weight relationship was W = 0.0071TL2.97. in order to calculate the fecundity, sub-samples were taken from the anterior, median and posterior parts of 15 ovaries in the ration of 2 - 5% of the ovary weight and the mature oocytes were counted. As a result, the species’ fecundity was found to be between 4,600- 9,800 (6,110±1,755). the relationship between total length and fecundity was computed as W= 1,640.7 TL-13,907 and a linear relationship was determined

Length-weight relationships of three macrourid fishes in the eastern Aegean Sea, Turkey

Symposium on Grenadiers of the World Oceans - Biology, Stock Assessment, and Fisheries held at the 136th Annual Meeting of the American-Fisheries-Society -- SEP 11, 2006 -- Lake Placid, NYWOS: 000258525400013Length-weight relationships of three macrourid fishes (saddled grenadier Coelorinchus coelorhincus (formerly known as Caelorinchus caelorhincus), glass-head grenadier Hymenocephalus italicus and bluntsnout grenadier Nezumia sclerorhynchus from Sigacik Bay on the Turkish coast of the Aegean Sea are presented. Overall, 923 specimens of three different species of the family Macrouridae were weighed and measured. The sample size ranged from 43 for bluntsnout grenadier to 782 for saddled grenadier. The values of the exponent b in the length-weight regressions (W=aL(b)) varied between 2.51 (glasshead grenadier) and 3.49 (bluntsnout grenadier). Regressions of length-weight relationships were significant for all species. Positive allometry in weight vs. length for bluntsnout grenadier, isometry in saddled grenadier, and negative allometry for glasshead grenadier were observed.Amer Fisheries So

Population size and structure of the African Softshell Turtle, Trionyx triunguis, in Dalaman, southwestern Turkey

WOS: 000406791900004We assessed the size of the population of the African Softshell Turtle, Trionyx triunguis, in Dalaman (Mugla, Turkey), which is considered to be the largest population of the species in the Mediterranean, by using the Jolly-Seber mark-recapture method. A total of 415 individuals were caught during the summer months of 2009 to 2011, of which 148 were recaptures. From 267 marked individuals, 148 (55%) were male, 69 (26%) were female and 50 (19%) were juveniles and subadults of indeterminate sex. The male: female ratio was calculated to be 2.14:1. By using Model A' of the Jolly-Seber mark-recapture method, which includes deaths but no immigration, the mean population size in Kukurt and Kucukdalyan (Kargin) lakes, together with Tersakan and Taslicay creeks, were estimated to be 396 +/- 36. Based on this estimation, the population density was calculated to be 14 turtles/ha. Approximately 67.4 % of the estimated population was marked. The mean capture probability (p) and mean survival ratio (Phi) were 0.094 +/- 0.009 and 0.957 +/- 0.076, respectively. Our results showed that the species' population size is larger than previously estimated based on visual counts. The status "Vulnerable" C2a of the IUCN Red Data Book categories seems therefore more appropriate for the Mediterranean subpopulation of Trionyx triunguis than "Endangered" C2a.Ege University Funding Organization [07SUF005]This work was supported by the Ege University Funding Organization under Grant 07SUF005, and it was approved by the Local Commission on the Ethical Use of Laboratory Animals of Ege University. This study is part of the PhD thesis of Salim Can Akcinar

Length-weigth relationships for syngnathid fishes of the Aegean Sea, Turkey

WOS: 000250305900014In this paper we present length-weight relationships of three pipefishes, Syngnathus acus, Syngnathus typhle Nerophis ophidion, and two seahorse species, Hippocampus hippocampus, Hippocampus guttulatus from izmir Bay, on the Turkish coasts of the Aegean Sea. Overall, 1010 specimens of five different species of Syngnathidae were weighed and measured. The sample size ranged from 29 for H. hippocampus to 570 for S. acus. The values of the exponent b in the length-weight regressions (W=aLb) varied between 2.42 (N. ophidion) and 3.54 (S. acus). Linear regressions of length-weight relationships were significant for all species. Positive allometry in weight vs. length for S. acus, isometry in S. typhle and H. hippocampus and negative allometry for H. guttulatus and N. ophidion were observed

The reproductive biology of the Great Pipefish Syngnathus acus (Family: Syngnathidae) in the Aegean Sea

WOS: 000266997900019With the aim of determining the reproductive characteristics and mating periods specific to Syngnathus acus, a study was carried out from December 2001 to November 2002 in the Camalti Lagoon (Izmir Bay, Aegean Sea). Study material consisted of 605 individuals that were captured using a beach seine in areas with vegetation. 43% (n=261) of the captured individuals were female, 25% (n=154) were male and 31% (n=190) were juveniles that were not sexually mature. The female-male ratio was 1:0.58. Mean total length values in females and males were 113.1 and 111.4 mm, respectively. The abundance of females carrying oocytes and of pregnant males of the species was observed between March-August 2002, coinciding with the period of relatively warmer water temperatures in that year. Gonadosomatic index (GSI %) analyses of females found that the reproductive period was between March-September. The relationship of egg/embryo number with total length in pregnant males and the total length-batch fecundity relation in females was statistically insignificant. We found that there were three groups of oocytes in the ovaries of females. Average oocyte diameter varied between 0.4-1.8 mm (developing 0.4-0.5mm, 0.7-0.8mm and 1-1.8mm hydrated oocyte group); thus, there were three spawning events during a year. The ratios of annual fecundity (mean: 65) and partial fecundity (mean: 28) data support this result (three spawning a year). Average hydrated oocyte number of females was 28, average egg number in the pouch of a male was 24, and average embryo number was 31. Average egg diameter in pregnant males was 1.42 mm (min:1, max:1.85); average length value of pre-larva and post-larvae was 8.91 ram, (min:3, max:14.29) and 13.29 mm (min: 9.71 max:15.29).Ege UniversityEge University [2001 SUF 003]The material used in this study was gathered in the frame of the "Fishes and their reproductive periods in Tuzla Lagoon and Urla Coasts of Izmir Bay' project (Project No: 2001 SUF 003), financially funded by Ege University. We are grateful to the project staff