A study on growth, reproduction and stock assessment of stripped venus (Chamelea gallina Linnaeus 1758) in the Western Marmara Sea

The samples of C. gallina were captured 0-10 m of depth between October 2003 and September 2004 on Gelibohi-Cankaya coast, Marmara Sea. The mean lenght of C.gallina was measured 26,5 mm on October, 24,8 mm on November, 29,0 on December, 29,0 on January, 28,6 mm on March, 27,9 mm on April, 19,3 mm on May, 25,6 mm on June, 26,6 mm on August and 24,7 mm on September, respectively. The maximum and minimum height values were determinated as 10 mm and 35 mm, respectively. The maximum height frequency of individuals was % 73,6 with 20-30 mm. The total weight of C.gallina individuals ranged from 1,15 g to 22,16 g. Maximum density of total weight distribution were between 1 and 7 g. Mean height, weight, lenght of all samples values were 26,191 mm, 6,538 g, 23,447 mm, respectively. The height classes occurred the most frequent were % 8,5 with 26 mm, % 8,4 with 24 mm and % 8,1 witii 25 and 27 mm. The length-weight relationship of C.gallina was estimated as W=0,0005 * L2-8921. In this study, height-lenght, height-thickness and total weight-meat weight relationships were determinated as linear but, lenght-total weight and lenght-meat weight relationships were non-linear. Correlation analysis was constracted for established direction and strenght of the relationships between variables made regression analysis. Correlation values were determinated between 0,5 and 1,0. This data was showed that the relationships between biological parameters of C.gallina were positive and strong. Age was determined using 127 individuals which the surface shell rings read easly. Average length values of individuals in each groups were 13,25 mm in age group I, 22,24 mm in age group JJ, 25,52 mm in age group III, respectively. The maximum age group was VTJ (38 mm). Von Bertalanffy growth parameters of C.gallina was calculated L»= 43,80 mm, K= 0,214, to = -1,194 year. There was a little difference between observed and calculated.mean lengths. 43First gonadal maturity in the samples collected from Gelibolu-Çankaya coast. occurred on May. In this period, there was small eggs in the gonads and it was distributed seldomly. On June, mature sperm and eggs in the gonads were determined. On August, spawned and small gonads were determined. Biomass of C.gallina on Gelibolu-Çankaya coast between 3 and 10 m of depth was found 313,7 (±120) tones. In this period, average unit catch was calculated 125,1 kg/h, the lowest unit catch was (3,07 kg/h) on January 2004 and the highest unit catch was on August 2004. 44