Ontogenetic changes in temperature preference of Atlantic cod

• Published in: Journal of Fish Biology
• Main Authors: Lafrance, P., Castonguay, M., Chabot, D., Audet, C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: atlantic cod; Gadus morhua
• Online Access: http://dx.doi.org/10.1111/j.0022-1112.2005.00623.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0022-1112.2005.00623.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0022-1112.2005.00623.x

Final thermal preferendum ( T ) experiments were conducted in a horizontal thermal gradient tank from the beginning of August 2001 to mid‐November 2001 using Atlantic cod Gadus morhua from 6·5 to 79·0 cm fork length ( L F ). The value of T varied significantly ( P < 0·005) with L F ( T = 7·23–0·054 L F ), with smaller (younger) fish choosing higher temperatures than larger (older) fish. The preferendum varied from 6·9° C for fish of 6·5 cm to 3·0° C for those of 79·0 cm. Experiments comparing fish positions in the gradient tank between thermal gradients of 0·5–11·0 and 4·5–14·5° C demonstrated that fish positions were determined by temperature selection instead of undesirable tank effects. This study is the first to demonstrate the effect of ontogeny on temperature preferences of a marine fish species.