IX.—The Biology of the Euphausiid Crustacean, Meganyctiphanes norvegica (M. Sars).

Synopsis Analyses of winter and summer vertical migrations of Meganyctiphanes norvegica are given and the differences in behaviour pointed out. A vertical layering of size classes, larger specimens occurring deeper than smaller ones, is shown to exist during the day and night. Four potential methods...

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Bibliographic Details
Published in:Proceedings of the Royal Society of Edinburgh. Section B. Biology
Main Author: Mauchline, J.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1959
Subjects:
Online Access:http://dx.doi.org/10.1017/s0080455x00000734
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0080455X00000734
Description
Summary:Synopsis Analyses of winter and summer vertical migrations of Meganyctiphanes norvegica are given and the differences in behaviour pointed out. A vertical layering of size classes, larger specimens occurring deeper than smaller ones, is shown to exist during the day and night. Four potential methods of feeding were found. The inter-relationships between vertical migration, feeding method used, and type of food eaten are discussed. The relationship of carapace length to total length was found to depend on the state of maturity of M. norvegica . M. norvegica matures at the age of 1 year, transference of the spermatophores taking place in January-February, the eggs being laid in March-April. The larvae take 2–3 months to reach adolescence and little growth in size takes place in the winter when the gonads are maturing. An age of 3 years may be attained but most only survive 1½—2 years. The distribution within the Clyde Sea throughout the year is described. Most of the population were found to move to the North-east Arran Area for egg-laying. A 24-hr. and annual periodicity of luminescence is described and correlated with the period of swarming of this species prior to spermatophore transference.