Determination of population parameters of four-spotted megrim (Lepidorhombus boscii Risso, 1810) from Saros Bay (Northern Aegean Sea)

The four-spotted megrim samples were collected between September 2006-2008 using a commercial bottom trawl net with 44 mm codend mesh size at depths ranging from 0 to 500 m in Saroz Bay. The average total length and total weight of the individuals were calculated as 21.5±0.452 cm and 118.82± 2.869 g, respectively. The average total length and total weight of the females, males and females-males were 25.6±0.323 cm, 202.68±7.352 g; 17.6±0.266 cm, 50.00±2.678 g; 23.2±0.273 cm, 157.15±5.783 g, respectively. The sex ratio was calculated as 1:0.424 (F:M). Length-weight relationships were calculated separately for females, males, females-males and all samples as: W=0.0032TL3.31, W=0.0069TL3.04, W=0.0035TL3.29 and W=0.0039TL3.25, respectively. Age distribution ranged from I to XIII years. The von Bertalanffy growth equations were computed as L?=49.8 cm, k=0.09 year-1, t0=-2.15 year for females; L?=39.1 cm, k=0.11 year-1, t0=-2.59 year for males; L?=50.6 cm, k=0.09 year-1, t0=-1.99 for all samples. The growth performance index (??) was found to be 2.35, 2.23 and 2. 36 for female, male and all samples, respectively.The size at first maturity was at 14.9 cm for females and 15.3 cm for males.Fecundity-length relationships, fecundity-weight relationships and fecundity-age relationships were estimated as F=1.487TL3.22, F=264.39W+14.103 and F=12.207A-11.279, respectively. Total (Z), natural (M) and fishing (F) mortalities of four-spotted megrim from Saros Bay were found as 0.31 year-1, 0.24 year-1 and 0.07 year-1, respectively. The exploitation rate (E) is 0.23 year-1. Maximum sustainable yield is 11.3 ton. Total length-otolith length is TL=4.9653OL+4.8915.