Investigation catch composition and length frequency of s. putnamae caught by surface gillnet in the chabahar port waters(oman sea)

The purpose of this research was to investigate the catch composition and length frequency of S. putnamae using Four meshe sizes of 64, 83, 95 and 110 mm in gillnet in the February (winter) and June (Summer) 2022, in the coastal waters of Sistan and Baluchistan province. In the Sampling period, 22 species were caught, in the summer season, the highest catch rate was 33.04% for the S. putnamae and P. pelagicus was the least caught with 0.37% , and in the winter season, S. putnamae was the most caught with 35.68% and T. croaker the lowest catch rate of 0.31%. Also, The rate of by-catch was 17.10%, A. thalassinus the highest percentage of by-catch. The highest length frequency with 52.8% for 83 mm mesh size in the summer and the highest length with 57.2% for 95 mm mesh size obtained in winter. the comparison of the length frequency of S. putnamae caught by different mesh sizes in summer and winter season and the average length of S. putnamae in the different mesh sizes showed that there is a significant difference between them. Also, the comparison between the mesh sizes showed that the 83 mm mesh size in summer and the 95 mm mesh size in winter had a significant difference with the size of other and similar mesh size in other seasons. The results showed that more fish were Snagged in smaller mesh size and more fish were Gilled in larger mesh size.