Trophic ecology of Humboldt squid, Dosidicus gigas, in conjunction with body size and climatic variability in the Gulf of California, Mexico
Trophic ecology of Humboldt squid, Dosidicus gigas, in conjunction with body size and climatic variability in the Gulf of California, Mexico
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DOI：
10.1002/lno.11343
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发表时间：
2019-10
影响因子：
4.5
通讯作者：
Elan J. Portner;U. Markaida;C. Robinson;W. Gilly
中科院分区：
文献类型：
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作者：
Elan J. Portner;U. Markaida;C. Robinson;W. Gilly
在过去的二十年里，加州湾（GOC）经历了三次强烈的厄尔尼诺事件（1997-1998年，2009-2010年和2015-2016年），每次事件之后都是成熟的洪堡鱿鱼（Dosidicus gigas）的地幔长度急剧减少（从>60厘米到<20厘米）。然而，目前尚不清楚与强厄尔尼诺事件相关的海洋学变化如何影响D. gigas饲料，限制了我们的能力，以评估相对重要性的温度和食物供应的表型反应的D。对环境变化的影响我们对D.在过去三次厄尔尼诺事件之前，期间和之后，GOC中的gigas发现，尽管其饮食在大范围的身体大小（8-85厘米）中变化不大，但在海面温度和叶绿素a浓度方面观察到显著和可预测的饮食变化。在相对凉爽的环境中（蛹）和相对温暖的环境中（蕈蚊）消耗大量相对较小、高热量的猎物，可能是在成熟前生长到大体型所必需的。当温暖，非生产性的条件下盛行的GOC，只有小鱿鱼存在，并以磷虾和翼足类，猎物与相对低的热量值占主导地位的饮食。使用一个时间序列的饮食数据，这项工作提供了独特的见解的中层水饲料社区的海洋变化和环境变化对海洋捕食者的营养生态的影响。
Over the past two decades, the Gulf of California (GOC) has experienced three strong El Niño events (1997–1998, 2009–2010, and 2015–2016), each of which was followed by a drastic reduction in mantle length of mature Humboldt squid, Dosidicus gigas (from >60 cm to <20 cm). However, it is unclear how the oceanographic changes associated with strong El Niño events affected the midwater organisms on which D. gigas feed, limiting our ability to assess the relative importance of temperature and food availability in the phenotypic response of D. gigas to environmental variability. We quantified the diet of D. gigas in the GOC before, during, and following the past three El Niño events and found that although its diet varied little across a large range of body sizes (8–85 cm), significant and predictable diet variability was observed with respect to sea surface temperature and chlorophyll‐a concentration. Consumption of large numbers of relatively small, high calorie prey in both relatively cool (anchovies) and relatively warm, productive conditions (myctophids) is likely necessary to support growth to large body sizes before maturation. When warm, unproductive conditions prevailed in the GOC, only small squid were present and had diets dominated by euphausiids and pteropods, prey with relatively low caloric value. Using a time series of diet data, this work provides unique insights into the response of a midwater forage community to oceanographic variability and the effects of environmental variability on the trophic ecology of an oceanic predator.