东太平洋赤道海域茎柔鱼的营养生态位和肠道微生物组成

掌握海洋生物的营养生态位特征及其应对环境变化的响应机制,对于评估渔业和气候变化对海洋生态系统功能的影响至关重要.茎柔鱼(Dosidicus gigas)是东太平洋重要的渔业经济物种,在生态系统中具有承上启下的重要生态作用.在气候变化的大背景下,掌握茎柔鱼应对气候变化的响应过程将有利于合理把控其资源状况.本研究采用稳定同...

Trophic niche and gut microbiota of Dosidicus gigas in the eastern equatorial Pacific Ocean

Understanding the adaptation of important marine species to environmental changes is critical for evaluating the effects of fisheries and climate change on marine services. The jumbo squid, Dosidicus gigas, is a keystone species in the eastern Pacific, which plays an intermediate role in the marine food web. Better understanding of their responses to climate change would be a big step to understand their population dynamics. In this study, stable isotope and high-throughput 16 S rRNA sequencing were used to compare the variation of trophic niche, gut length, and gut microbiota of D. gigas in the eastern equatorial water during normal and El Nino periods. The results showed a significant variation in δ¹³C values for D. gigas in different periods, indicating differences in their food sources. The main phylum-level gut microbiome included Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Proteobacteria, and Tenericutes. There was no significant difference in the gut microbial composition during normal and El Nino periods, but differences in gut microbial diversity and relative abundance of some phyla bacteria. El Nino events could decrease the trophic niche breadth of D. gigas, and positively impact gut length and gut microbial diversity and richness. Firmicutes, Bacteroidetes, Spirochaetes, WPS-2, and Kiritimatiellaeota had a significant increase in the gut microbiota of D. gigas combined with a more concentrated intraspecific rank of distance during El Nino, suggesting that the changes of habitat and food sources caused by El Nino events could limit the distribution range of D. gigas. D. gigas might change their digestive system to improve the digestive and absorption capacity and enhance their immunocompetence. Such a climate-driven alteration might help D. gigas rapidly adapt to the changes of environmental conditions and food resources under El Nino.