Table_1_Diversity of Pacific Agathotanais (Peracarida: Tanaidacea).pdf

Agathotanais is one of the seven genera classified into the family Agathotanaidae. So far, 12 species have been described for the genus, seven of which are known from the Pacific. However, considering the present poor state of knowledge on deep-sea environments, a much higher number of Agathotanais species than currently known can be suspected. Among the studied material, collected from below 1,000 m during five deep-sea expeditions in different parts of the Pacific Ocean, we identified eight species: two of them were already known to the science and five species were identified as new to knowledge and their formal description is presented in the paper: two from the North West Pacific (the Sea of Okhotsk and Kuril-Kamchatka Trench), two from the Central Pacific (Clarion-Clipperton Fracture Zone), and one from the Australian slope. The eighth Agathotanais species in our material was determined using a molecular approach, but it was represented by only one partially destroyed individual and could therefore not be formally described. The proportion of Agathotanais collected at the Sea of Okhotsk was the highest (22%), whereas the numbers were substantially lower for the Kuril-Kamchatka Trench, and the Central and the Southern Pacific. Molecular analyses confirmed the monophyly of Agathotanais and Paragathotanais and a close relationship between both genera. Moreover, a close relationship between the two Australian species was revealed. As a result of our findings, the number of species known from the Pacific increased from 5 to 11, with the total number of species in this genus increasing from 12 to 17. An updated identification key for Agathotanais species is given.

阿加托塔纳虫属（Agathotanais）是阿加托塔纳虫科（Agathotanaidae）下的7个有效属之一。截至目前，该属已被正式描述的物种共计12种，其中7种记录于太平洋海域。然而，鉴于当前人类对深海环境的认知仍存在较大空白，阿加托塔纳虫属的实际物种数量大概率远超目前已报道的水平。本次研究的样本采集自太平洋不同海域的1000米以深水域，依托5次深海科考任务获取。经鉴定，这批样本共包含8个物种：其中2种为科学界已知物种，5种为新发现物种，本文将对这5个新种进行正式描述——它们分别采自西北太平洋的鄂霍次克海与千岛-堪察加海沟（各2种）、中太平洋的克拉里昂-克利珀顿断裂带（Clarion-Clipperton Fracture Zone，2种），以及澳大利亚大陆坡（1种）。本次样本中的第8个阿加托塔纳虫属物种通过分子生物学方法完成鉴定，但该物种仅存1只部分破损的标本个体，因此无法进行正式分类描述。鄂霍次克海采集到的阿加托塔纳虫属样本占比最高，达22%；而千岛-堪察加海沟、中太平洋与南太平洋的采集占比则显著较低。分子生物学分析证实，阿加托塔纳虫属与副阿加托塔纳虫属（Paragathotanais）均为单系群，且二者亲缘关系密切。此外，本研究还揭示了两个澳大利亚物种间存在紧密的亲缘关系。经本次研究更新，太平洋海域已知的阿加托塔纳虫属物种数量从5种增至11种；该属的全球已知物种总数则从12种提升至17种。本文同时提供了更新版的阿加托塔纳虫属物种分类检索表。