Larvae of deep-sea invertebrates harbor low-diversity bacterial communities

Microbial symbionts are a common life-history character of marine invertebrates and their developmental stages. Communities of bacteria that associate with the eggs, embryos, and larvae of coastal marine invertebrates are species-specific and correlate with aspects of host biology and ecology. The richness of bacteria associated with the developmental stages of coastal marine invertebrates spans four orders of magnitude from single mutualists to 1,000s of unique taxa. If the developmental stages of coastal species are broadly representative of marine invertebrates then we may expect deep-sea species to associate with bacterial communities that are similar in diversity. To test this, we used amplicon sequencing to profile the bacterial communities of invertebrate larvae from multiple phyla (annelids, molluscs, crustaceans) collected from 2,500 to 3,670 meters depth in near-bottom waters near hydrothermal vents in three different regions of the Pacific Ocean (East Pacific Rise, Mariana Ba...微生物共生体是海洋无脊椎动物及其发育阶段常见的生活史特征。定殖于近岸海洋无脊椎动物卵、胚胎及幼虫体内的细菌群落具有物种特异性，且与宿主的生物学及生态学特性密切相关。近岸海洋无脊椎动物发育阶段相关细菌的物种丰富度跨度达四个数量级，从单一互利共生菌到数千个独特分类单元不等。若近岸物种的发育阶段可广泛代表海洋无脊椎动物类群，则可推测深海物种所共生的细菌群落多样性水平与之相近。为验证这一推测，本研究采用扩增子测序（amplicon sequencing）技术，对太平洋三个不同区域（东太平洋海隆、马里亚纳海盆[原文未完结]）热液喷口附近水深2500至3670米的近底层水域中采集的多门类（环节动物门、软体动物门、甲壳动物门）无脊椎动物幼虫的细菌群落进行了解析。