北部湾剑尖枪乌贼生物学特征及资源状况变化的初步研究

根据2007年北部湾4个季度的调查资料,进一步对北部湾渔场剑尖枪乌贼（Loligo edulis）的生物学特征及资源状况进行分析。结果表明,调查期间剑尖枪乌贼的最大平均胴长、体质量和优势胴长组、体质量组出现在秋季。雌性个体数量明显高于雄性,性成熟度以Ⅱ期为主。雌、雄性开始分化的最小胴长为56 mm,性成熟最小胴长为67 mm。全年摄食强度不高,以1级为主。幼体终年存在。与1997～1999年和2000～2002年的调查相比较,渔获率的季节间变化显著。该调查中剑尖枪乌贼的出现率和平均渔获率较1997～1999年有所上升,较2000～2002年均有下降,显示该海域剑尖枪乌贼的资源量波动较大,因此,对剑尖枪乌贼资源应加以合理利用和保护。

Biological characteristics and stock changes of Loligo edulis in Beibu Gulf,South China Sea

Based on the data collected from Beibu Gulf,South China Sea in four seasons of 2007,the biological characteristics and stock changes of Loligo edulis were analyzed.The results show that individuals at the biggest mantle length and body weight as well as the dominant mantle length and body weight groups of L.edulis occurred in autumn.Female squids outnumber males significantly and mature stageⅡ dominats the population.The smallest mantle length for sex-differentiation and sexual maturation are 56 mm and 67 mm,respectively.The feeding intensity（grade 1） is low and larval swordtip squids are found throughout the year.Compared with the results of 1997~1999 and 2000~2002,the seasonal changes of the catch rate are evident.The occurrence rate and average catch rate of L.edulis in 2007 increase compared with the data of 1997~1999,while decrease compared with that of 2000~2002.The results indicate that the stock of L.edulis in Beibu Gulf fluctuates rather greatly and should be appropriately used and protected.