New Zealand Journal of Marine and Freshwater Research abstracts
Distribution, growth rate, and death from octopod and gastropod predation of Tawera bollonsi (Bivalvia: Veneridae) at the Auckland Islands
PENELOPE A. LUCKENS
New Zealand Oceanographic Institute
DSIR Marine and Freshwater Research
Department of Scientific and Industrial Research
Private Bag, Kilbirnie, Wellington, New Zealand
Abstract
Tawera bollonsi, originally described from five valves whose colour suggested their derivation from a comparatively late fossiliferous deposit, is a common bivalve living at the Auckland Islands. Discoloration occurs during life and not after death. Its shell is more inflated than in any other
Tawera species. It lives in mud, sandy mud, and fine sand in the inlets and harbours, often with the crustaceans
Callianassa filholi and
Heterosquilla tricarinata and the bivalve
Chione aucklandica. The size frequency of both living specimens and valves is bimodal. For the living specimens the main peak is at 6-8 mm, with a secondary peak at 38-40 mm. The main peak for valves is at 25-37 mm with a secondary peak at 5 mm. Growth rate is very variable and may be genetically determined. Predation rates for both octopus and gastropod predation varied considerably but, with one exception, were less than 20%. Octopus predation, not previously been reported from waters as cold as the subantarctic Auckland Islands, is a more common cause of death than gastropod predation.
Keywords Tawera bollonsi; Bivalvia; Veneridae; distribution; size frequency; growth; octopus predation; gastropod predation; subantarctic; Auckland Islands
New Zealand Journal of Marine and Freshwater Research, 1991, Vol. 25: 255-268 0028-8330/2503-0255 $2.50/0 © Crown copyright 1991
Received 25 February 1990; accepted 30 July 1991
PDF file of entire paper: medium quality (1429K); (scanned from paper original: notes about this process)
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