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Natural history of ctenophores in the Resolute Passage area of the Canadian High Arctic with special reference to Mertensia ovum

1992; Inter-Research; Volume: 86; Linguagem: Inglês

10.3354/meps086133

1616-1599

TD Siferd, RJ Conover,

Marine and environmental studies

The natural h~story of ctenophores from the Resolute Passage area of the Canadlan High Arctic was examined in 1985 and 1986 The seasonal abundance of 3 ctenophore species, Mertensia ovum, Beroe cucums, and Bolinopsis infundibulum, are reported M ovum was by far the most abundant accounting for 88 9 % of all ctenophores collected, and because of its abundance received the most study The M ovum population developed similarly in both years reaching a maximum abundance of 911 m-2 in early June 1986 The lipofuscin age-pigment technique suggested that M ovum can l ~v e for at least 3 yr Gut contents showed A4 ovum to be a n opportunistic feeder, but the copepods Pseudocalanus acuspes Calanus glacialis and C hyperhoreus and the amphipod Parathemlsto libellula formed most of the d ~e t M ovum was estimated to consume between 4 and 10 % d.' of the standlng crop of macrozooplankton in Resolute Passage ' Contribution Number 16 from the Resolute Bay Marine Laboratory of dissolved nutnents through excretion into the water column (Biggs 1977, Park & Carpenter 1987).In the Canadian Arctic, a single ctenophore species, Mertensia ovum, makes up 60 to 95 % of the total calories in the macrozooplankton community (Percy & Fife 1985).However, until fairly recently the ecology of this important predator had not been investigated.Percy (1989) found a population in Frobisher Bay that varied little in abundance over the year, although it was considerably smaller than populations offshore in Baffin Bay (Huntley et al. 1983, Percy 1989).Swanberg & BAmstedt (1991) have recently modelled the predation potential of M. ovum in the Barents Sea, estimating that this population could consume between 1 and 5 % d -' of the copepods in the water colun~n.Here, we examine the role of ctenophores in a high arctic marine ecosystem, first by giving a brief account of the natural history of the ctenophores in Resolute Passage (Northwest Territories, Canada), and second by describing the feeding ecology of the dominant gelatinous zooplankter, the cydippid ctenophore Mertensia ovum.