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

Some 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.