基于体长和复眼直径的南极大磷虾种群年龄结构分离研究

基于2013年2—3月南极普里兹湾南极大磷虾(Euphausia superba)样品的复眼直径和体长数据,使用Normsep方法对大磷虾种群年龄结构组成进行分离研究,结果表明:利用复眼直径和体长数据分离出的大磷虾年龄组均为1+—4+龄,群体年龄以2+龄为主;复眼直径的分离效果优于体长,其结果更为可靠;1+—3+龄磷虾复眼直径平均值分布范围为1.21—1.40 mm、1.59—1.76 mm和1.93—2.08 mm,4+龄复眼直径约为2.23 mm;从20世纪80年代至今,普里兹湾附近海域大磷虾各年龄组的平均体长分布变化不大,表明大磷虾种群体长特征稳定,其资源状况较好。

ANTARCTIC KRILL AGE STRUCTURE BASED ON BODY LENGTH AND EYE DIAMETER

Antarctic krill (Euphausia superba) population age structure was determined using the Bhattachaya method, with data on compound eye diameter and body length taken from krill collected from Prydz Bay between February and March 2013. Of four apparent age groups, the most dominant was 2⁺, with eye diameter measurements better differentiating age cohorts than body length. Average eye diameter of 1⁺–3⁺ krill ranged 1.21–1.40 mm, 1.59–1.76 mm and 1.93–2.08 mm respectively, with those of 4⁺ krill being approximately 2.23 mm. Since the 1980s, body-length characteristics of Antarctic krill have remained stable, suggesting krill resources around Prydz Bay have not been over-explored.