南大洋极锋以南常见磷虾类生殖特性研究进展

Reproductive traits of common Euphausiids in the south of Antarctic Polar Front

磷虾是南大洋生态系统的基本组成部分,它们在南极海洋食物网中扮演着关键角色。磷虾可能是人类未开发的最大动物蛋白质来源,人类对磷虾资源开发的兴趣日趋增加,但目前关于这些种类的基础生物学,尤其是除南极大磷虾以外的其他磷虾类繁殖特性的了解极为匮乏。本文对已有相关研究进行梳理,揭示了不同种磷虾卵巢发育经历相似的生理步骤;磷虾卵母细胞大小存在区域性差异;通过观察第二性征和卵巢形态可以划分雌性磷虾的发育阶段;磷虾种间产卵期具有纬度差异,种内具有区域差异;多数调查发现样本中雌性磷虾个体占优。在此基础上,本文对今后的研究重点提出展望:1)加强南极大磷虾之外磷虾生殖特性的研究,探索磷虾生殖特点的季节性、区域性对磷虾环南极分布的影响;2)重点关注实验生物学研究,厘清磷虾的产卵次数及机制,以期准确估算繁殖力以评估磷虾资源开发可能产生的影响。

Euphausiids(krill) is a basic component of the Southern Ocean ecosystem, with a key role in the Antarctic marine food web. Krill may be the largest unexploited animal protein source for human beings. There is a great deal of interest in exploiting krill resources. Our understanding is poor about the biology of those species, particularly the reproductive traits of krill species, expect for Euphausia superba. Here, we reviewed related studies and revealed that different species of krill undergo similar physiological steps during ovary development. There are regional variations in the size of krill oocytes. The sexual maturity stages of female krill could be classified by observing the thelycum and ovarian morphology. There are latitudinal variations in spawning periods among species and regional variations within species. Most observations showed that krill samples are dominated by females. Future research should be conducted, i.e.,(1) strengthening the study on the reproductive traits of krill, besides Euphausia superba, and further to explore the effects of seasonal and regional reproductive traits on the distribution of krill around Antarctica,(2) focusing on experimental biology in order to clarify the mechanism of spawning times of krill and further to calculate accurately the fecundity to evaluate the impacts of exploiting krill resource.