摘要:

Larval paddlefishPolyodon spathulawere raised in tanks from hatching to metamorphosis at four constant water temperatures (16, 20, 24, and 28°C) and fed three salmonid diets with different physical densities. Larvae reared at 20°C and fed either of the two diets with the slower sinking rates had the best growth and survival at 30 d posthatch; survival ranged from 65 to 81%, and body weight ranged from 838 to 850 mg. A temperature of 24°C was sublethal and 28°C was lethal, whereas 16°C depressed survival and growth. Dietary nutrient content affected the proximate composition of larvae.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1992)121<0538:EOWTAF>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The relationship between predator avoidance deficits induced by a simple handling stress and the level of plasma corticosteroids was determined for juvenile coho salmonOncorhynchus kisutch. Groups of fish were held out of water for 1 min, then allowed to recover from this stress for 1, 90, or 240 min. After each recovery period, some unstressed and stressed fish were sampled for plasma cortisol, and others were subjected to predation by lingcodOphiodon elongatus. Levels of corticosteroids in stressed fish remained high throughout the 240-min period of recovery, but predator avoidance returned to control levels in less than 90 min. Results suggest that juvenile coho salmon quickly recover basic survival skills of predator avoidance after mild stress, even though cortisol levels continue to indicate a stressed condition.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1992)121<0544:NCOPAC>2.3.CO;2

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659-121.4.548

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659-121.4.555

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor