Age, growth and food composition of Scorpaena porcus (Linnaeus, 1758) in the southeastern Black Sea

Samples of 525 Scorpaena porcus (Linnaeus, 1758) were collected from the southeastern Black Sea between January 2002 and May 2003 for information on age, growth, length weight relationships and stomach contents. Total length of sampled fish ranged from 4.6 to 22.9 cm and total weight from 1.3 to 220 g. The sex ratio (1 : 1.61) was biased toward females (P < 0.05). Positive allometric growth was determined in the collected samples. The length-weight relationship for all individuals was described by the parameters a = 0.0149 and b = 3.09, with r(2) = 0.99. The sample was composed of five age-classes (0-7 years). Three growth models were used to identify the growth characteristics: von Bertalanffy, L-t = L-inf[1 - exp(-k(t - t(0)))]; logistic, L-t = L-inf/[1 + ((L-a - L-0)/L-0)][exp(-rt)]; and Schnute and Richards, L-t = L-inf[1 + alpha exp(-at(c))]((-1/b)). Among these, the Schnute and Richards model was best fitted to the data as L-t = 21.34[1 + 2.38exp(-0.34t(1.58))]((-1/0.99)) The diet was composed of Carcinus mediterraneus (18.2%), Crangon crangon (12.1%), unidentified crab species (10.6%), Gobius sp. (4.6%), Palaemon sp. (4.5%), Macropipus sp. (4.5%), Engraulis encrasicholus (1.5%), Gastropoda (1.5%), and unidentified remains (34.9%).