Determination of some biological characteristics and population parameters of the blotched picarel (Spicara flexuosa Rafinesque, 1810) distributed in the Eastern Black Sea (Rize - Hopa)

Abstract

This study was carried out in order to determine some biological characteristics of the fish species of Spicara flexuosa, which is distributed on the Eastern Black Sea coast, and to contribute to the management of the picarel in all the seas of our country. Between October 2015 and September 2016, 599 fish samples were obtained and examined in the laboratory. It was determined that the examined individuals were distributed between the ages of I-VII which 31.22% of the population was male and 68.78% was female. The minimummaximum total length values of the samples were between 8.7 and 21.8 cm; and the weight values ranged from 7.1 to 129.94 g. It has been determined that the mean total length of males is statistically different from that of females (P<0.05). Von Bertalanffy growth equilibrium was calculated as “L∞=22.71 cm TL, K=0.243 year-1, t0=-2.306 year-1; W∞=118.27 g” for females, “L∞=38.34 cm TL, K=0.063 year -1, t0 = -6.381 year-1; W∞=755.37 g” for males, and “L∞=33.42 cm TL, K=0.080 year -1, t0=-5.381 year-1; W∞=401.24 g” for all individuals. The length-weight relation of all individuals was found as W= 0.0118*L2.9727 (R2 =0.9487). When the ratio of gonadosomatic index (GSI) data and gonadal maturity stages were examined over the year, it was determined that the reproduction of the picarel in the Black Sea occurred between June and September