Population dynamics of the Indian white prawn (Penaeus indicus H. Milne Edwards, 1837) in the Oman Sea (coastal waters of Sistan and Baluchistan)

Shrimp fishing is considered a precious industry among the fishing communities of Sistan and Baluchistan province, which is a part of the income of fishermen and related industries. Carapace length (CL) (mm) and total weight (g), and the catch data of Penaeus indicus were collected from the sampling sites in the eastern and western coastal waters of Sistan and Baluchestan. The samples were collected duringa period of 30 months, from 21 March 2018 to 22 September 2020, which come from the bottom gillnets made of nylon monofilament and stretched mesh sizes of 35 and 53 mm. The length ranged from 14 to 67 mm CL, averaging (±standard error) at 39.3±0.88 mm CL. Recruitment occurred in two periods,one in early spring and another in late summer. Growth parameters for males were calculated as L∞ = 62.75 mm CL, and K=1.57 year-1 andt0 =-0.0813 year-1, and for females the parameters wereL∞ = 71.01 mm CL, and K=1.23 year-1 andt0 =-0.101year-1. According to the Y/R model, the optimal mean length at first capture corresponding to the maximum yield per recruit (Lm50opt.) was estimated as Lc50 opt=47.2 mm CL for P. indicus, which showed the maximum fishing effort to harvest the stock. When the current fishing mortality is applied to the model, Lc50 was calculated as 45.4 mm, suggesting the maximum fishing effort is suggested the fishing fleet. The average CPUE showed that in the last week of September, its level is at its maximum value and reached the lowest level in late October. These results provide the parameters needed to establish the appropriate times of opening and closing the shrimp fishing period in the region for each year, aiming at harvesting the stock at an optimal fishing effort level.