Simple harpacticoid composition observed at deep hydrothermal vent sites on sea knoll calderas in the North-west Pacific. (7th September 2021)

• Record Type: Journal Article
• Authors: Nakasugi, Futa; Shimanaga, Motohiro; Nomaki, Hidetaka; Watanabe, Hiromi Kayama; Kitahashi, Tomo; Motomura, Yusuke; Iseda, Koki
• Is Part Of: Journal of the Marine Biological Association of the United Kingdom. Volume 101:Number 6(2021)
• Page Start: 947
• Page End: 956
• Publication Date: 2021-09-07
• Subjects: Chemosynthesis -- chimney -- community composition -- copepod -- deep sea -- meiofauna; Biology -- Periodicals; Marine biology -- Periodicals; 578.77
• DOI: 10.1017/S0025315421000874
• Languages: English
• ISSNs: 0025-3154

Abstract

Abstract: Dirivultid copepods (Siphonostomatoida), one of the most successful meiobenthic organisms found at deep-sea hydrothermal vents, have been the focus of most previous ecological studies among meiofauna in these habitats. The ecology of Harpacticoida, a major benthic copepod group in typical deep-sea floor, however, is not well understood in terms of variations in community structure and controlling factors at venting sites. The spatial heterogeneities in benthic harpacticoid composition and their association with environmental parameters were investigated at hydrothermal vent chimney structures in the calderas of three neighbouring sea knolls (Bayonnaise Knoll, Myojin Knoll and Myojin-sho Caldera) in the western North Pacific. While a previous study had reported the distribution of dirivultids was strongly associated with spatial differences in stable carbon isotopic signatures (δ 13 C) of organic matter in the detritus on active chimneys in the field, multivariate analyses detected no significant corelation between the parameter and harpacticoid composition in this study. Instead, high associations of the harpacticoid composition with differences in water depth and total organic carbon (TOC) concentration were detected. Ectinosomatidae dominated at vent sites with lower TOC values in the shallowest Bayonnaise Knoll, while they were less prevalent at deeper vent fields in the other knolls, where Miraciidae was the most abundant family. This study indicated the availability of vent chemoautotrophic carbon is not a primary factor controlling the composition of harpacticoids even in the habitats on the hydrothermal vents, but instead by the food amount, regardless of its resources (including marine snow from the sea surface), in the study area.