2020年夏季南极南奥克尼群岛裘氏鳄头冰鱼胃含物组成及食性分析

Stomach content and diet of mackerel icefish (Champsocephalus gunnari) in South Orkney Islands, Antarctic during summer 2020

摘要:

裘氏鳄头冰鱼(Champsocephalus gunnari)作为南大洋冰鱼科(Channichthyidae)的代表,不仅具有重要的经济价值,同时也是南大洋生态系统中的重要物种。裘氏鳄头冰鱼主要摄食南极磷虾,同时也是高营养级生物的捕食对象。研究裘氏鳄头冰鱼的食性,对于了解南极磷虾种群资源变动,预测高营养级生物的生存和发育至关重要。对南奥克尼群岛裘氏鳄头冰鱼的胃含物分析表明,该鱼种的饵料分为南极磷虾(Euphausia superba)和长脚虫戎(Themisto gaudichaudii)两大类,其中:南极磷虾在裘氏鳄头冰鱼食物组成中占绝对优势,其出现频率和数量百分比分别为100%和99.9%;剩余饵料为长脚虫戎。广义线性模型(Generalized linear model,GLM)分析结果显示,空间因素(经度)有显著影响,即裘氏鳄头冰鱼摄食南极磷虾的数量与距南奥克尼群岛的距离成正比。裘氏鳄头冰鱼体长-胃含物质量关系为S_M=6.639 6e^{0.017 9L},胃含物质量和日消化量随着体长的增加而增加,而日消化率为 0.98%~2.08%。研究结果可为了解裘氏鳄头冰鱼摄食生态学提供基础信息,为南奥克尼群岛裘氏鳄头冰鱼资源养护提供参考。

Abstract:

As a representative of the Channichthyidae in Southern Ocean, Mackerel icefish (Champsocephalus gunnari) not only has important economic values in fishery, but also plays a vital role in the Antarctic marine ecosystem. C. gunnari feeds mainly on Antarctic krill (Euphausia superba) and is also the prey of higher predators. It is very important to study the feeding habits of C. gunnari for understanding the variations in E. superba resources and predicting the survival and development of high-trophic organisms. The results of this study showed that the diet of C. gunnari can be divided into two groups, of which E. superba was dominant in the diet composition, and the frequency and quantity percentage were 100% and 99.9% respectively. The remaining diet was Themisto gaudichaudii. The results of Generalized Linear Model showed that the number of E. superba in the stomach of C. gunnari increased with the distance of sampling locations to the South Orkney Islands. The relationship between standard length and stomach content mass of C. gunnari was S_M=6.639 6e^{0.017 9L}. Stomach content mass and daily consumption increased with the increased standard length, while daily consumption percentage remained between 0.98% and 2.08%. The results of this study can provide basic information for understanding the feeding ecology of C. gunnari and provide data for resource conservation of C. gunnari in the South Orkney Islands.