Contribution to some biological aspects of invasive marbled spinefoot (Siganus rivulatus, Forsskal 1775) from the Turkish coast of southern Aegean Sea

Cerim, Hasan/0000-0003-3025-1444WOS: 000535739700012Some biological aspects of marbled spinefoot (Siganus rivulatus) were determined from a southern Aegean Sea small-scale fishery. A total of 721 individuals were captured (335 females, 279 males and 87 immature) and sex ratio was found to be 1:1.27, female to male. Total lengths and ages of individuals ranged between 9.0-26.1 cm and 1-9 years. Asymptotic length (L-infinity), growth coefficient (K) and the theoretical age at zero length (t(0)) were estimated to be 27.7 cm, K = 0.162 y(-1) and t(0) = -1.87 y. Length at maturity value was determined as 16.6 cm for females and 16.84 cm for males. Although S. rivulatus is one of the target species for small-scale and recreational fishery in the Turkish coast of the southern Aegean Sea, especially in Gokova Bay, official landing data is lacking for Turkey. Results of the present study are of crucial importance for further fisheries management of this invasive species.Ege University Scientific Research Projects Coordination UnitEge University [2016/SuF/014]This study is supported by Ege University Scientific Research Projects Coordination Unit. Project Number: 2016/SuF/014

Maximum size of Marbled spinefoot (Siganus rivulatus Forsskal & Niebuhr, 1775) for Aegean Sea

WOS:000606513400008This study presents the maximum size record of Siganus rivulatus for the Aegean Sea with some additional biological information. The biggest individual of S. rivulatus was caught in Akbuk Bight, Gokova Bay (Southern Aegean Sea) at 15 m depth with trammel nets on 29.01.2018. Specimenof marbled spinefoot was 27.1 cm in total length and 414.8 g in total weight. The specimen was female with a gonad weight of 2.43 g and it was determined to be 9 years old. The total length of the mentioned individual is the longest for Aegean Sea among the reported studies so far and weight measurement displays the maximum value not only for Turkey but also for European waters.Ege University Scientific Research Projects Coordination UnitEge University [2016/SUF/014]This study was supported by Ege University Scientific Research Projects Coordination Unit. Project Number: 2016/SUF/014

MORTALITY AND EXPLOITATION OF MARBLED SPINEFOOT, SIGANUS RIVULATUS (ACTINOPTERYGII: PERCIFORMES: SIGANIDAE), FROM SOUTHERN AEGEAN SEA SMALL-SCALE FISHERY

WOS: 000553162900006Background. in the small-scale fisheries of the Gulf of Gokova (Turkish coast of the southern Aegean Sea) the marbled spinefoot, Siganus rivulatus Forsskal et Niebuhr, 1775, is a commercially important species. No sustainability study, however, has been carried out on the stock assessment and management of this species in the gulf. the aim of the presently reported study was to determine the mortality and biological reference points of Siganus rivulatus and suggest a proper fishery management plan for fishery regulations. Materials and methods. the sudy was conducted between July 2016 and June 2018. Fish samples were collected from the Gulf of Gokova small-scale fishery. the total mortality (Z), natural mortality (M), fishing mortality (F-curr), and exploitation rate (E-curr) were determined and compared with the biological reference points: the optimum fishing mortality (F-opt), fishing mortality limit reference point (F-lim), optimum exploitation rate (E-opt). Results. Total mortality (Z), natural mortality (M), fishing mortality (F-curr), and exploitation rate (E-curr) were found to be 0.67, 0.32, 0.35, and 0.52, respectively. Furthermore, biological reference points (F-opt, F-lim, E-opt) attained co values of 0.16, 0.21, and 0.33 cm, respectively. Conclusion. the fishing pressure for Siganus rivulatus stocks the Gulf of Gokova should decrease for the sake of the sustainability of this resource.Ege University Scientific Research Projects Coordination UnitEge University [2016/SUF/014]This study is supported by the Ege University Scientific Research Projects Coordination Unit. Project Number: 2016/SUF/014