Effects of fluctuating temperature on mortality, stress, and energy reserves of juvenile coho salmon

Journal Article · Wed Jan 01 00:00:00 EST 1986 · Trans. Am. Fish. Soc.; (United States)

DOI:https://doi.org/10.1577/1548-8659(1986)115<52:EOFTOM>2.0.CO;2· OSTI ID:5003097

Thomas, R E; Gharrett, J A; Carls, M G; Rice, S D; Moles, A; Korn, S

The effects of fluctuating diel temperature cycles on survival, growth, plasma cortisol and glucose concentrations, liver weight, and liver glycogen of juvenile coho salmon Oncorhynchus kisutch were determined. Temperature cycles (10-13/sup 0/, 9-15/sup 0/, 8-17/sup 0/, and 6.5-20/sup 0/C) were selected to stimulate observed temperatures in clear-cuts of southeastern Alaska. Different levels of feeding, including starvation, were used in each of the tests. LT50s (peak temperature within a cycle producing 50% mortality) were 28/sup 0/C for age-0 fish (350 mg) and 26/sup 0/ for age-II fish (22-g presmolts). Cyclic temperatures for 40 d, averaging 11/sup 0/C daily, did not influence growth of age-0 fish on any food ration as compared to controls held at a constant 11/sup 0/C. Plasma cortisol and glucose concentrations were significantly greater in fish maintained for 20 d in the 6.5-20/sup 0/C cycle but not different in fish in 10-13/sup 0/ and 9-15/sup 0/ cycles or a constant 11/sup 0/C. These elevated concentrations may be indicators of long-term stress. Plasma cortisol concentrations were lower in starved fish than in fed fish at all temperature regimes; however, fluctuating temperature did not enhance starvation effects on cortisol levels. Diel temperature cycles did not affect liver weights or liver glycogen concentrations.

• Research Organization: National Marine Fisheries Service, Auke Bay, AK
• OSTI ID: 5003097
• Journal Information: Trans. Am. Fish. Soc.; (United States), Vol. 115:1
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
HYDROCORTISONE
BLOOD CHEMISTRY
SALMON
TEMPERATURE EFFECTS
ALASKA
BIOLOGICAL STRESS
DAILY VARIATIONS
GLUCOSE
GROWTH
JUVENILES
ADRENAL HORMONES
ALDEHYDES
ANADROMOUS FISHES
ANIMALS
AQUATIC ORGANISMS
CARBOHYDRATES
CORTICOSTEROIDS
FEDERAL REGION X
FISHES
GLUCOCORTICOIDS
HEXOSES
HORMONES
HYDROXY COMPOUNDS
KETONES
MONOSACCHARIDES
NORTH AMERICA
ORGANIC COMPOUNDS
PREGNANES
SACCHARIDES
STEROID HORMONES
STEROIDS
USA
VARIATIONS
VERTEBRATES
560205* - Thermal Effects- Vertebrates- (-1987)