Research Associate, Royal British Columbia Museum, 675 Belleville Street, Victoria, British Columbia, Canada V8W 9W2..
Zootaxa. 2021 Mar 30;4950(2):zootaxa.4950.2.1. doi: 10.11646/zootaxa.4950.2.1.
Fourteen species of hydroids, collected during August 2019 by ROV SuBastian of the Schmidt Ocean Institute, are reported from the Emperor Seamount chain in the western North Pacific Ocean. Two others, Candelabrum sp. and Eudendrium sp., were observed only on videos taken by the ROV. From collections and video observations, eight species of hydroids were found at Jingū Seamount, three at Yomei, Nintoku, and Annei seamounts, and one at Koko Seamount and Hess Rise. At Suiko and Godaigo seamounts, hydroids were seen in videos but they could not be identified. Latebrahydra schulzei, an endobiotic associate of the hexactinellid sponge Walteria flemmingii Schulze, 1886 from Annei Seamount and Hess Rise, is described as a new genus and species tentatively attributed to Hydractiniidae L. Agassiz, 1862. Another new species, Hydractinia galeai, is described from Jingū Seamount. Among its distinctive characters is a zooid termed a sellectozooid, likely serving in both food capture and defence. Hydroids examined from Yomei, Nintoku, and Jingū seamounts are elements of a cold-water fauna occurring in the North Pacific Boreal Bathyal province, while those of Annei and Koko seamounts, and Hess Rise, are part of the biota of the Central North Pacific Bathyal province. Hydroids identified as Bouillonia sp., from Nintoku Seamount, represent the first record of this predominantly deep water tubulariid genus in the North Pacific Ocean. Bonneviella superba Nutting, 1915, from Jingū Seamount, is reported for the first time outside the Aleutian Islands. Bonneviella cf. gracilis Fraser, 1939, known elsewhere only from Dease Strait in the western Canadian Arctic, was also collected on Jingū. In addition to hydroids, medusae of Ptychogastria polaris Allman, 1878 were observed on videos from Nintoku, Jingū, Annei, and Koko seamounts at depths between 2423-1422 m. An unidentified siphonophore was observed near bottom at 2282 m on Nintoku Seamount.
十四种水螅虫，由施密特海洋研究所的 ROV SuBastian 于 2019 年 8 月采集，来自西太平洋的皇帝海山链。另外两种，Candelabrum sp. 和 Eudendrium sp. 仅在 ROV 拍摄的视频中观察到。从采集和视频观察中，在 Jingū 海山发现了八种水螅虫，在 Yomei、Nintoku 和 Annei 海山各发现了三种，在 Koko 海山和 Hess Rise 发现了一种。在 Suiko 和 Godaigo 海山，水螅虫仅在视频中可见，但无法识别。Latebrahydra schulzei，一种内共生的六放海绵 Walteria flemmingii Schulze，1886 的伴生物，来自 Annei 海山和 Hess Rise，被描述为一个新属和种，暂时归属于 Hydractiniidae L. Agassiz，1862。另一种新种，Hydractinia galeai，来自 Jingū 海山。其独特的特征之一是一种被称为 sellectozooid 的水螅虫，可能同时用于食物捕获和防御。从 Yomei、Nintoku 和 Jingū 海山采集的水螅虫是北太平洋北部冷水动物群的一部分，而 Annei 和 Koko 海山以及 Hess Rise 的水螅虫是中北太平洋深水动物群的一部分。在 Nintoku 海山发现的被鉴定为 Bouillonia sp. 的水螅虫代表了这个主要生活在深海中的管水母目 Tubulariidae 属在北太平洋的首次记录。来自 Jingū 海山的 Bonneviella superba Nutting，1915，报告了该物种在阿留申群岛以外的首次记录。Bonneviella cf. gracilis Fraser，1939，已知仅在加拿大北极西部的迪斯海峡，也在 Jingū 被采集到。除了水螅虫，还在 Nintoku、Jingū、Annei 和 Koko 海山的视频中观察到 Ptychogastria polaris Allman，1878 的水螅水母，深度在 2423-1422 米之间。在 Nintoku 海山 2282 米深处的底部附近观察到一种未识别的水螅水母。
