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Observations on swimming, posture and buoyancy in the giant oceanic ostracods, Gigantocypris mulleri and Macrocypridina castanea
Published online by Cambridge University Press: 11 May 2009
Abstract
Gigantocypris is a good swimmer, capable of moving fast enough to overtake a variety of zooplanktonic Crustacea and chaetognaths. It swims smoothly without violent accelerations and decelerations. Previous reports of unstable weak swimming in this species stem from the study of overheated animals; Gigantocypris is stenothermal, adversely affected at temperatures above about 15°C. Gigantocypris is nearly neutrally buoyant (sinking speed 0·2 mm s−1) and is capable of hovering for long periods with the aid of slight movements of the propulsive antennae. When swimming quickly Gigantocypris achieves an average speed of 164 mm s−1 (9·6 mm body length; 391 antennal beats min−1) at 12·5°C. It is unlikely that Gigantocypris performs significant diurnal vertical migrations. The heart of Gigantocypris is large and beats at ca 100 beats min−1. Macrocypridina is a faster swimmer (<52·3 mm s−1 (8·3 mm body length) at 12·5°C with an antennal frequency of 583 beats s−1), but each beat is accompanied by great accelerations and decelerations. Macrocypridina is dense, sinking at 40 mm s−1. Macrocypridina is eurythermal, its swimming speed increasing steadily between 11·5 and 20°C.
- Type
- Research Article
- Information
- Journal of the Marine Biological Association of the United Kingdom , Volume 70 , Issue 1 , February 1990 , pp. 43 - 55
- Copyright
- Copyright © Marine Biological Association of the United Kingdom 1990
References
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