Journal of the Marine Biological Association of the United Kingdom

Research Article

Biodiversity in midwater cnidarians and ctenophores: submersible-based results from deep-water bays in the Japan Sea and north-western Pacific

Dhugal J.  Lindsay a1c1 and James C.  Hunt p1
a1 Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, 237-0016, Japan

Article author query
lindsay dj   [PubMed][Google Scholar] 
hunt jc   [PubMed][Google Scholar] 


Biodiversity of cnidarian and ctenophore forms in Toyama Bay, Japan Sea, was lower than that in Sagami Bay, north-western Pacific, according to all the indices investigated. Highest richness of forms occurred in the 400—600 m depth layer in Sagami Bay, while in Toyama Bay richness was low in most layers. New forms continued to occur with increasing depth in Sagami Bay but not in Toyama Bay and species composition differed remarkably between the two bays. Putative secondary deep-sea gelatinous forms were identified. Horizontal patchiness in normalized abundances was the rule rather than the exception and for accurate calculations of biodiversity indices incorporating evenness or equitability, the necessity for multiple submersible dives in a single area and survey period was noted. Vertical migration and predation were identified as possible factors contributing to the higher diversity in the 400—600 m depth layer in Sagami Bay.

(Received August 30 2004)
(Accepted March 24 2005)

c1 e-mail:
p1 Department of Biology, University of New England, 11 Hills Beach Road, Biddeford, ME 04005, USA