摘要:

The effects of dissolved oxygen (DO) on incubating salmonid embryos have been studied extensively in the laboratory but there is little information on levels experienced by salmon embryos in complex natural channels. We monitored 33 natural egg pockets of chum salmonOncorhynchus keta, from shortly after spawning until emergence, and found that DO levels varied considerably among and within egg pockets over time. Egg pocket DO levels varied from 2–10 mg l−1at the time of spawning and generally declined during incubation but the declines did not occur in all pockets and were not always steady. Much of the variability may be attributed to local channel topography. Pool tailouts had the highest and least variable DO levels whereas levels in lateral bars were generally lower and more variable. Levels in glides and riffles tended to be intermediate between those in pool tailouts and lateral bars. In spite of the variation in DO levels and habitats used by chum salmon, DO levels were not correlated with egg pocket sediment composition (per cent of the sample<1.0 or 4.0 mm diameter) or with the egg pocket's de

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1996.tb01424.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

A female Atlantic salmon × brown trout hybrid was backcrossed to a male brown trout. Electrophoretic analysis of diagnostic enzymes showed that the progeny were triploid. However, a few individuals were partially diploid

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1996.tb01425.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Rainbow trout under low pH conditions acquire heavy infections withTrychophrya intermedia, not secondary to gill damage, which suggests that the parasite may have a primary effect on gill function in fish Under acid Conditions.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1996.tb01426.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Hypervariable minisatellite DNA single‐locus profiling and mitochondrial DNA analysis revealed that 18.48% of juvenile Atlantic salmonSalmo salarin Troutbeck, a stream in the R. Leven catchment of the English Lake District, were hybrids between Atlantic salmon and brown troutS. trutta, and that hybridization was bidirectiona

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1996.tb01427.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1996.tb01428.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY