摘要:

Brook trout fry in Lawrence Creek consumed more chironomids, simuliids, and ephemeropterans than trichopterans or amphipods during their first 6 months of life. Diets of fry from different sections of the stream were similar. Fry captured from upstream sections were consistently longer (5 to 12 mm) than those taken from downstream sections. This differential is explained on a basis of preferential upstream migration of larger fry during the period of the study.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<130:TFOBTS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

After a 24-hr exposure to sublethal mercury concentrations of 0.1, 0.05 and 0.01 ppm Hg++, the ability of mosquitofish to avoid predation by bass was impaired. Fish exposed to 0.005 ppm Hg ++ were not affected. The degree of effect showed positive correlation with mercury concentrations.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<134:BAIASP>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Preservation of cisco (Coregonus artedii) and yellow perch (Perca flavescens) for 72 hr in 10% formalin or by freezing reduced median total length by 0.7–2.1% for both species and increased median condition factor by 6.3–9.4% for cisco and 4.8–8.8% for yellow perch. Formalin increased median weight by 1.8% for cisco and 5.0% for yellow perch; freezing and thawing reduced weight by 1.7–2.0% for each species. Changes in length, weight, and condition factor were not significant for unpreserved fish remeasured after 72 hr, suggesting that the above changes were not entirely due to errors in measurement. The study revealed that even small changes in length or weight due to preservation can produce large errors in condition factor.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<136:EOFAFO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The breathing and swimming activity rates of four bluegills in a laboratory version of a pollution monitoring apparatus increased when the diurnal temperature cycle changed from a control cycle of 24.8–26.0 C to a treatment cycle of 24.8–29.2 C. The latter cycle simulated the temperature regime reported for the Potomac River in June 1961, at a location free of extraneous thermal effluents. If a bluegill response is being used to detect industrial pollution, critical response values must be determined so that a diurnal temperature change does not cause a false warning signal. The results of this investigation suggest that this can be accomplished.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<138:TROBLM>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A suitable technique for marking large numbers of small fish is subcutaneous injection of acrylic polymer emulsions. Nine of 15 colors used in mark-recapture studies were discernible for 4 mo or longer.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<140:ATATEO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The astomous condition of a carp Cyprinus carpio from Texas resulted from healing of a recent injury. The specimen is emaciated and probably survived primarily off its own tissue reserves.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<142:AMCFT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

An artificial spawning substrate for brook trout (Salvelinus fontinalis Mitchill) was developed for use in laboratory bioassay studies involving reproduction. The substrate consisted of a glass spawning box containing a compartmented screen egg retainer on top of which was placed a coarse screen with attached gravel to simulate the stream bottom. Egg viability from wild and hatchery trout spawning on this substrate averaged 96%. This new substrate design reduces considerably the time required to determine daily spawning activity in laboratory brook trout experiments.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1974)103<144:ALSSFB>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1974.10492864

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1974.10492870

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1974.10492871

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor