Effects on temperature on spontaneous and thyroxine‐stimulated locomotor activity of Atlantic cod

Spontaneous locomotor activity of cod Gadus morhua maintained at 6° C tripled from February to May. In contrast, locomotor activity of cod held at 2° C was significantly lower than at 6° C (between 25 and 65% lower) and the seasonal increase was smaller. Plasma levels of both thyroxine (T 4 ) and tr...

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Bibliographic Details
Published in:Journal of Fish Biology
Main Authors: Castonguay, M., Cyr, D. G.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1998
Subjects:
Online Access:http://dx.doi.org/10.1111/j.1095-8649.1998.tb00982.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1998.tb00982.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1998.tb00982.x
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Summary:Spontaneous locomotor activity of cod Gadus morhua maintained at 6° C tripled from February to May. In contrast, locomotor activity of cod held at 2° C was significantly lower than at 6° C (between 25 and 65% lower) and the seasonal increase was smaller. Plasma levels of both thyroxine (T 4 ) and triiodothyronine (T 3 ) did not differ between 2 and 6° C. T 4 injection increased locomotor activity by 10% for both temperature regimes. These data indicate that low water temperature reduces locomotor activity associated with migration in cod and that thyroid hormones are not involved in this decrease. This study provides a possible mechanism through which cold waters may affects migration and distribution of cod via its Effects on locomotor activity and swimming speed.