The activity of deep-burrowing macrofauna strongly influences all biogeochemical processes in sublittoral soft sediments. Despite this key role, these organisms are difficult to sample and, thus, often remain ignored in environmental studies. This study is the first in comprehensively exploring the diversity of the macrosymbiotic communities associated with the dominant subtidal deep-burrowing invertebrates from the southern part of the Russian coast of the Sea of Japan, represented by the species of the genera Upogebia Leach, 1814 (Arthropoda: Crustacea: Decapoda) and Urechis Seitz, 1907 (Annelida: Polychaeta: Echiura). The associated symbiotic communities mostly consist of obligate, host-specific species, while those species found in burrows of both hosts are probably using them just as refuges. Most symbionts occurred solitary or in heterosexual pairs, likely due to aggressive and strictly territorial behavior. This is certainly a hidden biodiversity, as more than half of the species reported here were not previously known from these “relatively simple and well-studied” boreal marine ecosystems. Our findings also allowed us to describe a new species belonging to the symbiotic genus Hesperonoe Chamberlin, 1919 (Annelida: Polychaeta: Polynoidae), based on morphological and molecular evidences, the latter being here presented for this genus for the first time.

中文翻译：

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隐藏的洞穴同伴：日本海北部潮间带深洞穴无脊椎动物的大型共生组合

深埋大型动物区系的活动强烈影响沿岸软沉积物中的所有生物地球化学过程。尽管起着关键作用，但这些生物很难取样，因此在环境研究中经常被忽略。这项研究是首次全面探索与日本海俄罗斯海岸南部潮汐深潜无脊椎动物相关的大型共生群落的多样性，该物种以1814年Upogebia Leach属的物种为代表：甲壳纲：十足目）和Urechis塞兹（1907年，安妮莉达（Annelida）：波利查塔（Polychaeta）：埃希拉（Echiura）。相关的共生群落主要由专性的寄主特异性物种组成，而在两个寄主的洞穴中发现的那些物种可能会将它们用作避难所。大多数共生体可能是由于侵略性和严格的领土行为而单独或成对发生。这肯定是一个隐藏的生物多样性，因为以前从这些“相对简单且经过充分研究”的北方海洋生态系统中不了解这里报告的物种的一半。我们的发现还使我们能够根据形态和分子证据描述属于1919年Hesperonoe Chamberlin共生属的新物种（Annelida：Polychaeta：Polynoidae），该物种首次在此被提出。