摘要:

One hundred eleven active and 71 standard metabolic rate estimates were made on 90-g cutthroat trout Salmo clarki at five temperatures. Active metabolism was lowest at 5 C (363 mg O2kg-h) and highest at 15 C (597 mg O2kg-h). At 20 C and 24 C it was 559 and 491 mg/kg-h, respectively. Scope for activity ranged from a low of 316 mg O2kg-h at 5 C to a high of 486 mg O2kg-h at 15 C then down to 374 mg O2kg-h at 24 C. Standard metabolisms at 5, 10, 15, 20, and 24 C were 47, 73, 111, 129, and 117 mg O2kg-h respectively.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<552:TIOTOS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Eggs of lake whitefish (Coregonus clupeaformis) were incubated in a constant-flow incubator at constant temperatures of 0.5, 2.0, 4.0, 5.9, 7.8, and 10.0 C. The time from fertilization to median hatch was inversely related to temperature, and ranged from 41.7 days at 10.0 C to 182 days at 0.5 C. The percentage hatch was highest (70.9-73.3%) at 4.0, 5.9, and 7.8 C, and was greatly reduced (6.0-28.4%) at 0.5, 2.0, and 10.0 C. The mortality of embryos was greatest during the early stages of development. Abnormally developed fry were most frequent (85.9% of the hatch) at 10.0 C, and least frequent (2.8%) at 4.0 C. Mean lengths of fry at hatching were shorter at 7.8 and 10.0 C (12.4 and 8.8 mm, respectively) than at lower temperatures (13.1 to 13.5 mm). The optimum temperature range for incubation of lake whitefish eggs was 3.2 to 8.1 C. Equations were derived for predicting development time to 20 successive stages, and to hatching, at constant incubation temperatures and at fluctuating daily mean water temperatures.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<555:EODCIT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A 3n factorial experiment to evaluate the effects of an abrupt transfer of striped bass, Morone saxatilis, from a closed system rearing facility into a variety of experimental temperature and salinity combinations demonstrated a considerable hardiness of juvenile fish. Striped bass less than two months old had over 80% survival during seven days subsequent to acute introduction from the rearing facility into temperatures of 18 C or 24 C and salinities of 4 ppt or 12 ppt. Relative growth in these treatments was monitored, and the results suggest a degree of flexibility for stocking programs into estuaries.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<560:SAGOJS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Short-term bioassays were conducted with adult fathead minnows and hexavalent chromium, phenol, and sodium pentachlorophenate at 2 temperatures to determine the relationship of the 96-hour LC50to the lethal threshold concentration.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<567:TROTHL>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Toxicities were determined for two crude oils, one from the Persian Gulf (Iran) and one from the Sinai Peninsula (Gulf of Suez), to rabbitfish, Siganus rivulatus, an economically important species of teleost from the Red Sea. Also tested for toxicity were ST 5, a chemical oil dispersant, and oil-ST 5 mixtures in the ratio 10:1 vol/vol. Static tests conducted in small (3-liter) jars at 41‰ salinity and 23 C produced LC50(168 h) values of 0.74 ml/liter for Iranian crude, 14.5 ml/liter for Sinai crude, and 0.010 ml/liter for ST-5; LC50values for oil-ST 5 mixtures reflected biocidal properties of ST 5 alone. Iranian oil became less toxic with increasing time in seawater over a period of 168 hours; the reverse was observed for Sinai crude. ST 5 exhibited a dramatic reduction in lethality after 2 hours in the assay medium. The most toxic component tested of Iranian crude was the lowest-boiling fraction; with Sinai crude it was the highest-boiling fraction; with ST 5 the volatile surfactant component accounted for almost all deaths. Liver enlargement in rabbitfish was linked with exposure to comparatively high concentrations of crude oil. High sublethal levels of ST 5 caused reductions in blood hematocrit. Rabbitfish survival at a given petrochemical concentration was highest at intermediate salinities of 30-50‰ in the salinity range tested of 20 to 60‰. Rabbitfish were more resistant to crudes and oil-dispersant mixtures in continuous flow bioassays conducted in large tanks than in static jar bioassays. Tank tests also suggested that mortalities were higher among toxicant-stressed fish confined 0.2 to 1.0 meters from the surface than among fish held 1.0 to 1.8 m from the surface.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<571:TOCOAO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The 96-h LC50's for potassium permanganate (KMnO4) ranged from 0.750 mg/liter with channel catfish, Ictalurus punctatus, to 3.60 mg/liter with goldfish, Carassius auratus, in laboratory tests. The toxicity of KMnO4to fish is greatest in water of lower temperatures, in harder water, or in higher pH water. KMnO4is effective for detoxifying the fish toxicant antimycin in laboratory waters of pH 6.5 to 9.5. The half-life for antimycin exposed to 1.0 mg/liter of KMnO4ranges from 7 to 11 minutes in the different pH waters at 12 C.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<579:TOPPTF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

We investigated the toxicity of Aroclor 1016 to, and uptake by, fry and juvenile and adult sheepshead minnows (Cyprinodon variegatus) in intermittent-flow bioassays lasting 28 days. Survival of eggs, of fry hatched from them, and of juvenile and adult fish apparently was not affected by 0.1, 0.32, 1.0, 3.2, or μg/liter of Aroclor 1016 added to aquaria, but 32 and 100 μg/liter killed newly hatched fry and juvenile and adult fish. Sheepshead minnows accumulated the chemical in proportion to its concentration in the test water. Fry contained 2,500 to 8,100 X the concentration of Aroclor 1016 added to the test water, adults 4,700 to 14,000 X, and juveniles 10,000 to 34,000 X. As much as 77 μg/g of Aroclor 1016 in eggs from exposed adults apparently did not affect survival of embryos and fry.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<584:EOAROE>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Most uses of computers in fisheries science can be categorized as: (1) data tabulation, processing, and analysis; (2) automated and semi-automated monitoring systems; (3) educational, especially at the university level; (4) simulation to evaluate management strategies; (5) simulation to learn basic system properties, especially ecological interrelationships; or (6) facilitation of numerical analysis. A problem in renewable natural resource management is determining when and how the use of computer technology is warranted.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<589:CAIFS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

We describe a linear modeling technique that derives functions (parameters) of the predictor variables in a tabular form using a Fourier transformation technique. The result is a complex multiple regression model that is actually a series of models independently describing each parameter. This technique (1) provides an approximation to nonlinear modeling that is not restricted to a small number of variables, (2) does not require precisely formulated theoretical functions for each variable, and (3) avoids many of the restricting assumptions normally required for nonlinear modeling. The estimate of the total systematic information (variance) in the system and the amount of information predicted by the model can be used as a measure of the efficacy of the model. A production form of the model is being completed for use on the Missouri River mainstem reservoir system for predicting the effects of reservoir management practices on the indigenous fish populations.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<591:ACTSMF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A total ecosystem compartment model of a reservoir cove is described, with emphasis on the fish submodel. Nominal (unperturbed) annual cycles of selected compartments are presented, and results from three perturbation experiments (thermal pollution, eutrophication, piscivore invasion) are summarized. The ability of fishes to influence structure and function of the entire ecosystem (model) is demonstrated, and the role of top trophic levels in controlling the design of ecological communities is discussed. The status and prospects of total ecosystem modeling as a tool for fisheries science are considered.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<596:ARCEM>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor