Spawning biology and some biological parameters of the Indian white prawn Penseus indicus (Edwards, 1837) along Sistan and Baluchistan province (Oman Sea)

Indian white shrimp (Penaeus indicus) is the dominant species of shrimp with a high economic value in the coastal waters of Oman Sea. 

Materials & Methods:

 Biological data of gillnets fisheries were collected in two fishing grounds in the east (Pasabandar and Gwadar) and west (Pozim and Konarak) during the year 2018-2020.

By recording biological data on 2671 specimen of P. indicus, male to female sex ratio was obtained 1:1.17, which shows the predominance of female in the catch composition. The carapace length range (CL) was recorded at 14-58 mm for male, and 17-67 mm for female, with a mean length of larger female (40.1±1.22 mm) than male (38.4±1.26 mm). Data on CL and TL (Total length) by sex showed a significant linear relationship (p<0.05), which in general TL was 4.67 times larger than CL in females and 4.64 times larger than CL in males. The growth pattern was statistically negative allometric between CL and body weight (p<0.05), wherase it was isometric between TL and body weight )p<0.05). Spawning of P. indicus occurs throughout the year with two peaks; a major spawning in spring and a minor one in autumn. The smallest mature female was 31 mm CL, with a mean length at first maturity (Lm50%) of 37.7 mm.

Time closure on shrimp fishing during the main spawning season, and also catching shrimp with a mean length (CL) larger than Lm50% during the opening fishing season is necessary for optimal harvesting the stocks.