Seasonal changes in the calcium content of the blood of arctic cod

A well-marked seasonal cycle in the total calcium content of the plasma was shown to occur in adult cod, Gadus morhua L., of both sexes: these changes were not found in juvenile, immature cod. The changes in concentration of plasma total calcium appeared to be associated with gonadal maturation, the...

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Bibliographic Details
Published in:Journal of the Marine Biological Association of the United Kingdom
Main Author: Woodhead, P. M. J.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1968
Subjects:
Online Access:http://dx.doi.org/10.1017/s0025315400032434
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315400032434
Description
Summary:A well-marked seasonal cycle in the total calcium content of the plasma was shown to occur in adult cod, Gadus morhua L., of both sexes: these changes were not found in juvenile, immature cod. The changes in concentration of plasma total calcium appeared to be associated with gonadal maturation, the period of hypercalcaemia coinciding with the maturation cycle and the plasma calcium falling to a resting level again after spawning. Seasonal changes were greatest in the female cod and it is suggested that the raised level of calcium is associated with vitellogenesis in the ripening ovary, probably under the influence of oestrogens. The cycle in the male is not yet fully understood.