Study on the population structure and reproductive biology of Black scorpionfish (Scorpaena porcus, Linnaeus, 1758) in the Eastern Black Sea, Turkey

In this study, it was aimed to determine population parameters of (age, length, sex composition, relationship between age and length, growing parameters, condition factor, feeding, HSI, GSI, mortality, reproduction) black scorpionfish (Scorpaena porcus, Linnaeus 1758) in the shore of Trabzon.For this reason, 1061 scorpion fish, at total, had been catched monthly by gill net between January-December 2012. Samples were ranged from 6,7cm to 25,5 cm. Age was ranged 0-8. 409 females (38,55%), 465 males (43,38%) were confirmed by the gender analysis, 37 individuals (3,4%) were determined as immature and sexes of the 157 (14.14%) individuals couldn?t be established. There was significant difference between lengths and sexes of all samples according to Khi-Square Test (?2=115,58; p<0,01). The smallest individual in females had a length of 11,7 cm while it was 12,8 cm in males.Average lengths and weights were measured 15,47±2,868 cm and 83,60±52,193 g respectively while equation of length- weight relationship was determined as W=0,0101*L3,2546 and (r=0.96). Growth constants were determined as L?=22,15cm, K=0,287year-1, t0=-1,577 year and W?=446,06 g. Von Bertalanffy growing equations of all samples were determined as Lt=22,15*(1-e-0,287(t+1,577)), Wt=240,03*(1-e-0,287(t+1,577))3,2546. Instantaneous rate of mortality, rate of natural mortality and rate of fishery mortality were determined as (Z)=0.503, (M)=0.371 and (F)=0.132 respectively. Feeding diet was intensified on fish in winter (33%), spring (38%) and intensified on crabs in summer (57%), autumn (50%).Reproduction period was determined between June and October by GSI, HSI and histological studies. Fecundity was determined as 153.500±95.708 averagely in sexually mature individuals.Key words: Black Scorpionfish, Scorpaena porcus, growing parameters, reproduction, Black Sea.