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Fish growth, physiological stress, and tissue condition in response to rate of temperature change during cool or warm diel thermal cycles

Author:
Eldridge, William H., Sweeney, Bernard W., Law, J. Mac
Source:
Canadian journal of fisheries and aquatic sciences 2015 v.72 no.10 pp. 1527-1537
ISSN:
1205-7533
Subject:
Catostomus commersonii, Clinostomus, Cyprinella spiloptera, Ictalurus punctatus, Micropterus dolomieu, Pimephales notatus, Sander vitreus, animal growth, chronic exposure, cortisol, energy metabolism, fish, models, stress response, temperature, triacylglycerols, warm season
Abstract:
The effect of the rate of temperature change on fish was studied by exposing a variety of North American fish species to diel temperature cycles containing rates of change of 0.8, 1.1, 2.2, or 4.4 °C·h⁻¹. During a simulated cool season (3.9–11.7 °C), bluntnose minnow (Pimephales notatus), spotfin shiner (Cyprinella spiloptera), and white sucker (Catostomus commersonii), but not smallmouth bass (Micropterus dolomieu), gained mass in response to 0.8, 1.1, or 2.2 °C·h⁻¹ but not constant mean temperature. White sucker did not grow under 4.4 °C·h⁻¹, which was slower than expected based upon bioenergetics models. Physiological indicators of acute stress (day 1 cortisol), chronic stress (day 44 cortisol and triglycerides), and histomorphological measures suggested no effect of treatment. During a simulated warm season (20.0–27.8 °C), growth by channel catfish (Ictalurus punctatus), rosyside dace (Clinostomus funduloides), smallmouth bass, and spotfin shiner was not altered by any rate of temperature change; however, walleye (Sander vitreus) and white sucker grew slower than expected under 4.4 °C·h⁻¹. Physiological indicators of acute stress (day 1 cortisol), chronic stress (day 29 cortisol and triglycerides), and histomorphological measures suggested no effect of treatment. Chronic exposure to temperature change of 4.4 °C·h⁻¹ may not induce an acute or chronic stress response but may slightly impair growth for some species.
Agid:
5158129