Fishery and population characteristics of the Indian squids Loligo duvauceli Orbigny, 1848 from trawl survey along the north-west Red Sea

摘要

Fishery and population characteristics of Loligo duvauceli along the northwestern part of the Red Sea were studied based on samples from trawl survey by Research Vessel “Salsabile” May 2011 to assess the stock status of the Indian squids. It was the most common and abundant species of the total survey catch. Mantel lengths (ML) of Loligo were different between males, 45.0–238.0 mm; (mean 117.0 ± 36 mm, S.E. 0.179, n = 442) and females 43.0–162.0 mm (mean 115.0 ± 22 mm, S.E. 0.180; n = 287).The length frequency distribution revealed attendance of 3, 2 and 3 year classes for males, females and pooled sex, respectively. Growth parameters L ∞ , K were estimated at 246.8 mm, 0.8/year for males, 173.3 mm, 0.92/year for females and 246.8 mm, 0.85/year for the pooled sex. The longevity was 3.54, 3.08 and 3.33 years for males, females and pooled sex, respectively. Annual total, natural and fishing mortality were investigated at 4.24 ± 0.223/year, 1.27/year and 2.97/year, respectively. The exploitation ratio ( E ) was calculated at 0.7. The maximum ( E max ) was 0.56 for the highest yield. Higher value of the current ( E ) indicated the over exploitation of the Loligo fishery resource in the surveyed area.