西南大西洋阿根廷滑柔鱼生物学年间比较

将2007年2—5月、2008年3—5月、2010年1—3月我国鱿钓船在西南大西洋公海海域采集的阿根廷滑柔鱼样本,比较其不同年间的生物学特性。结果表明,渔获物雌雄比为1.14—1.50:1;3a雌性个体的胴长(体重)分别为188—346mm(110—856g)、200—364mm(145—950g)、124—276mm(72—425g),雄性个体的胴长(体重)为178—298mm(102—703g)、193—314mm(145—680g)、104—335mm(70—374g)。2010年渔获个体明显比2007和2008年小。各年间及雌、雄个体间的体重与胴长关系均存在差异(P<0.001),渔获物中年间性成熟组成差异明显,此外各年3月份渔获个体也存在显著差异。雌、雄个体的胴长平均生长率分别为0.53—1.07 mm/d、0.47—0.68 mm/d,相对生长率分别为0.24—0.41%d-1、0.23—0.33%d-1;雌、雄个体的体重平均生长率在1.70—5.25 g/d、1.64—4.59 g/d,相对生长率分别为0.92—1.37%d-1、0.86—1.40%d-1。渔汛期间,胴长、体重与时间的关系均符合指数生长曲线,但生长指数年间差异明显。综合分析认为:2007年渔获物基本上为南巴塔哥尼亚种群;2008年以南巴塔哥尼亚种群为主,但也有少量较小个体的夏季产卵种群;2010年则以夏季产卵种群为主,并有少量的南巴塔哥尼亚种群。

Annual variability in biological characteristics of Illex argentinus in the southwest Atlantic Ocean

Based on the samples from Chinese squid jigging vessels in the high sea waters of Southwest Atlantic in 2007, 2008 and 2010, the annual biological characteristics of squid Illex argentinus were studied and compared. The results showed that the sex ratio of catch was between 1.14~1.50:1 in three years. The mantle length (body weight) of female squid in three years ranged from 188 to 364 mm (110-856g), 200-364mm (145-950g), and 124-276mm (72-425g) respectively; the mantle length (body weight) of male squid in three years ranged from 178-298mm (102-703g), 193-314mm (145-680g) and 104-335mm (70-374g) respectively. The size of catch in 2010 were distinctly smaller than that in 2007 and 2008. The relationship between mantle length and body weight had significant difference in different sexes and years (P<0.001), and it also had significant difference in the composition of sexual maturity in three years. The average growth rates of mantle length for female and male were 0.53-1.07 mm.d-1 and 0.47-0.68 mm.d-1 respectively, and the average instantaneous relative growth rates for female and male were 0.24-0.41%d-1 and 0.23-0.33%d-1 accordingly. The average growth rate of body weight for female and male were 1.70-5.25 g.d-1 and 1.64-4.59 g.d-1 respectively, and the average instantaneous relative growth rates for female and male were 0.92-1.37%d-1 and 0.86-1.40%d-1 accordingly. The relationship between mantle length or body weight and time was suitable described by the exponential growth curve during the fishing seasons, but the growth index had significant difference among the three years. In conclusion, the individuals of the catch in 2007 almost belonged to the South Patagonic Stock (SPS), the individuals of the catch in 2008 mainly consisted of SPS, but had a few small individuals of the Summer-Spawning Stock (SSS), while in 2010 the SSS was the main part of catch and also a few small of SPS existed.