Sight unseen: Elucidating the trophic role and metapopulation structure of Southern Ocean gelatinous zooplankton using DNA metabarcoding

未见之景：利用 DNA 宏条形码阐明南大洋凝胶状浮游动物的营养作用和复合种群结构

• 批准号: 463092495
• 负责人: Dr. Charlotte Havermans, Ph.D.
• 金额: --
• 依托单位: Arbeitsgruppe Marine Zoologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/463092495?language=en
• 关键词: Sight; unseen; Elucidating; trophic; role

Gelatinous zooplankton (GZP) including pelagic ctenophores, cnidarians and salps are reputed to be climate change winners. In several marine ecosystems worldwide, they significantly increased in numbers over recent decades. This so-called “jellification” also holds for the warming region of Southern Ocean, with its notorious shift from a krill-based to a salp-based ecosystem. Besides salps, other Antarctic gelatinous zooplankton are barely studied, since this elusive component of the pelagic realm remained undetectable due to artefacts of traditional net sampling, overlooking GZP diversity and underestimating their abundances. Considering that GZP compose a large fraction of the pelagic biomass and will become even more central, their ecosystem impact as prey may similarly increase. Until recently, GZP were considered as a “trophic dead end”. This biased view finds it origin in the rapid digestion of the watery, soft tissues of GZP, making them “invisible” in predators’ stomachs for traditional microscopy, in the same way many are “invisible” in plankton samples. However, new approaches have shown that many taxa routinely consume GZP throughout the World Ocean. Here, we want to validate this paradigm shift for Southern Ocean pelagic and demersal ecosystems. To do so, we will investigate the spatio-temporal variation in diet composition and the occurrence of GZP predation for amphipod and fish species using a DNA metabarcoding approach. Subsequently, based on the millions of DNA reads obtained with this method and bioinformatic denoising, we want to conduct a metaphylogeographic study. By this, we aim to explore the genetic structure and population connectivity of the otherwise difficult to sample gelatinous zooplankton species.

胶状的浮游动物（GZP），包括上载体，CNIDARIAN和SALPS，被认为是气候变化的赢家。在全球几个海洋生态系统中，它们在近几十年来的数量大大增加。这种所谓的“果冻”也适用于南大洋的变暖地区，其臭名昭著的转变从基于磷虾的生态系统。除萨尔普斯外，其他南极凝胶浮游生物几乎没有研究，因为由于传统的净采样，忽略GZP多样性并低估了它们的丰富性，因此，由于传统的净采样，这种难以捉摸的层型组成部分仍然无法检测。考虑到GZP占上层生物量的很大一部分并将变得更加中心，因此随着猎物的影响可能会增加它们的生态系统影响。直到最近，GZP被认为是“营养的死胡同”。这种有偏见的观点发现它起源于水的快速消化，GZP的柔软尖端，使它们在掠食者的摊位中“看不见”用于传统显微镜的摊位，就像浮游生物样品中许多人一样，许多人都是“不可见的”。但是，新方法表明，许多分类单元在世界海洋中经常食用GZP。在这里，我们要验证南大洋山脉和塞尔萨尔生态系统的这种范式转变。为此，我们将使用DNA metabarcoding方法研究饮食组成的空间变化以及两亲和鱼类GZP捕食的发生。随后，基于使用这种方法和生物信息学获得的数百万个DNA读取，我们希望进行一项地层地理学研究。这样，我们旨在探索原本难以采样胶质浮游动物的遗传结构和种群连通性。