GEOMAR, Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany.
Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, 20013, USA.
Sci Rep. 2022 May 18;12(1):8282. doi: 10.1038/s41598-022-11844-y.
Gill parasites of coleoid cephalopods are frequently observed during remotely operated vehicle (ROV) dives in the Monterey Submarine Canyon. However, little knowledge exists on the identity of the parasite species or their effects on the cephalopod community. With the help of ROV-collected specimens and in situ footage from the past 27 years, we report on their identity, prevalence and potential infection strategy. Gill parasites were genetically and morphologically identified from collected specimens of Chiroteuthis calyx, Vampyroteuthis infernalis and Gonatus spp. In situ prevalence was estimated from video footage for C. calyx, Galiteuthis spp., Taonius spp. and Japetella diaphana, enabled by their transparent mantle tissue. The most common parasite was identified as Hochbergia cf. moroteuthensis, a protist of unresolved taxonomic ranking. We provide the first molecular data for this parasite and show a sister group relationship to the dinoflagellate genus Oodinium. Hochbergia cf. moroteuthensis was most commonly observed in adult individuals of all species and was sighted year round over the analyzed time period. In situ prevalence was highest in C. calyx (75%), followed by Galiteuthis spp. (29%), Taonius spp. (27%) and J. diaphana (7%). A second parasite, not seen on the in situ footage, but occurring within the gills of Gonatus berryi and Vampyroteuthis infernalis, could not be found in the literature or be identified through DNA barcoding. The need for further investigation is highlighted, making this study a starting point for unravelling ecological implications of the cephalopod-gill-parasite system in deep pelagic waters.
头足类海龙鱼的寄生甲壳动物经常在蒙特雷海底峡谷的遥控潜水器 (ROV) 潜水过程中被观察到。然而，对于寄生虫的种类或它们对头足类生物群落的影响，我们知之甚少。在过去 27 年的 ROV 采集标本和现场录像的帮助下，我们报告了它们的身份、流行率和潜在的感染策略。从收集的 Chiroteuthis calyx、 Vampyroteuthis infernalis 和 Gonatus spp. 标本中，通过遗传和形态学鉴定了鳃寄生虫。通过其透明的套膜组织，从视频片段中估计了 C. calyx、Galiteuthis spp.、Taonius spp. 和 Japetella diaphana 的原位流行率。最常见的寄生虫被鉴定为 Hochbergia cf. moroteuthensis，这是一种未解决的分类等级的原生动物。我们提供了这种寄生虫的第一个分子数据，并显示它与腰鞭毛目属 Oodinium 有姐妹群关系。Hochbergia cf. moroteuthensis 最常见于所有物种的成年个体中，在分析期间的全年都有观察到。C. calyx 的原位流行率最高 (75%)，其次是 Galiteuthis spp. (29%)、Taonius spp. (27%) 和 J. diaphana (7%)。第二种寄生虫，虽然没有在现场录像中看到，但在 Gonatus berryi 和 Vampyroteuthis infernalis 的鳃中发现，在文献中没有找到，也无法通过 DNA 条形码识别。需要进一步调查，这使得本研究成为揭示深海浮游水域头足类-鳃-寄生虫系统生态影响的起点。
