地理ジャーナルと自然災害
オープンアクセス

概要

Reproductive Biology of the Indian Oil Sardine Sardinella longiceps From Al-Seeb Waters off Oman

SM Al-Jufaili

The objective of this study is to examine the reproductive biology of the Omani-Indian oil sardine Sardinella longiceps from Al-Seeb area off the Omani waters. During the period January 2004–December 2008, a total of 1592 sardines were sampled. The lengths of the sampled fish ranged from 11.9 to 22 cm with a mean length of 16.5 ± 1.84 cm and modal length of 15.5 cm. Their weights ranged from 14 to 94.6 g with a mean weight of 42.43 ±15.19 g and modal weight of 43.7 g. The length–weight relationship equations analyzed for the combined sex, female, and male sardines were 2.99 W ? 0.009? L , 2.94 W ? 0.011?L , and
2.94 W ? 0.001?L , respectively. The length at 50% maturity for combined sex, female, and male
sardines was 16.35, 16.46, and 16.28 cm, respectively. During the study, the Omani sardines were observed to spawn in October, June, and July, September, June, and January and September during the years 2004, 2005, 2006, 2007, and 2008, respectively. During the sampling period, the relative condition factor Kn varied from one year to another and ranged from 0.36 to 1.46 with a mean of 0.9 ± 0.08. An overall mean sex ratio of 0.68 ± 0.02 proved to be significantly different from the expected theoretical sex ratio of 0.5 (?2 = 200; df = 1; P ? 0.05).