Systematics, ecology and biology of cirrate octopods: a workshop report

Cirrate octopods are conspicuous members of the benthopelagic and bathypelagic communities and include some of the largest invertebrates of the deep-sea. Although they have often been considered to be rare members of deep-sea communities, recent trawling has shown that the relative abundance of some cirrates, especially opisthoteuthids, may be locally or regionally high (e.g., Boyle et al., 1998). Cirrates also are presumed to be primitive, morphologically similar to ancestral octopods (Young et al., 1998), although recent observations indicate unexpected adaptations such as bioluminescence (Johnsen et al., 1999) and possibly diverse feeding modes (Vecchione and Young, 1997). Therefore, knowledge of cirrates may contribute substantially to understanding cephalopod evolution as well as deep-sea biology and ecology. However, because they are fragile, the condition of specimens collected up until the past decade generally has been very poor, and our knowledge of the group is rudimentary. New methods, such as videotapes recorded in-situ and gentle collection by submersibles, have allowed substantial new observations and renewed interest in the group.

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