Vol. 43 No. 2, 2004
Deep-sea Benthopelagic Calanoid Copepods and their Colonization of the Near-bottom Environment
Janet M. Bradford-Grieve
National Institute of Water and Atmospheric Research, P.O. Box 14901, Kilbirnie, Wellington 6001, New Zealand
Janet M. Bradford-Grieve (2004) We
are still in a discovery phase with respect to the deep-sea
benthopelagic fauna and its ecology. New species are being described
every year, and our knowledge of the physical and sedimentary
environments of the benthic boundary layer is currently being
extensively researched by a number of groups. Deep-sea, strictly
benthopelagic copepod populations (composed mainly of Calanoida) differ
in species composition from those in shallow and shelf waters and
probably all represent reinvasions of the benthopelagic environment
from the water column. The reasons for this difference are explored,
including the possible evolutionary paths of organisms that live in
this environment, and the physical conditions in which they live.
Oxygen availability was probably a limiting environmental factor in
geological time for benthopelagic calanoids. The low oxygen
requirements and low weight-specific respiration rates of benthopelagic
copepods are suggestive of a Permian reinvasion of the deep
benthopelagic environment. That is, they were selected for low oxygen
demand by the timing of their reinvasion of the deep benthopelagic
environment. It is possible that these hypotheses may be testable using
genetic information in the near future.
Key words: Arietelloidea, Clausocalanoidea, Paleoenvironment, Evolution, Colonization.
*Correspondence: Tel: 64-4-3860300. Fax: 64-4-3862153. E-mail: j.grieve@niwa.co.nz
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