摘要:

Results of bioassays and gas chromatographic analyses show that mosquitofish, Gambusia affinis, from near heavily-treated cotton fields near Belzoni, Mississippi (36-hr TLm= 1,000 ppb) and from an uncontaminated site near State College, Mississippi (36-hr TLm= 1 ppb) remove endrin from static test solutions at the same rate. A 500 ppb endrin solution produced 32% mortality in 50 susceptible fish in 25 min but required 144 hr in resistant fish. Relative mortality of fed and starved fish in endrin solutions and the rate of endrin uptake discount swallowing as the primary pathway of endrin entry into mosquitofish. About six times as much endrin is taken up via the exposed head region as is taken up by the general body surfaces. Oxygen requirements of the two populations are similar, but increase for susceptible fish at low endrin concentrations and for resistant fish at high concentrations coincident with the appearance of symptoms of endrin poisoning.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[335:DOEUAR]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Transportation of diazinon-C14and parathion-S35off a model cranberry bog following a simulated frost protection flood was shown 24 hr after application of the chemicals. Fish (Fundulus heteroclitus L.) and freshwater mussels (Elliptio complanatus Solander) were exposed to these contaminated waters and analyzed periodically. The majority of the chemicals disappeared from the water after 144 hr. During this time, no labeled metabolites of diazinon were detected; however, three labeled parathion degradation products were encountered. Accumulation of both pesticides occurred in the fish and mussels, often to levels far in excess of that present in the waters. The fish appear able to metabolize these accumulated chemicals at a faster rate than the mussels.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[345:WTODAP]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

A small ultrasonic fish tag is described, which is useful in studies of the game and pan fishes of freshwater lakes. The device emits a continuous signal of from 14 to 20 hr duration, at a frequency of 65 kilohertz. With the receiving equipment described, 37 white bass, Roccus chrysops (Raf.), have been successfully tracked in Lake Mendota for periods up to 13 hr.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[350:AUTFUI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The empirical importance of “angler success per unit of effort” as a quality determinant of recreational values was investigated with regard to three sport fisheries at Yaquina Bay, Oregon. A 10% increase in salmon (Oncorhynchus) angling success would induce a long-run increase in angling effort of approximately 10%, although bottomfish (sea perches, Embiotocidae; starry flounder, Platichthys; and other estuarine fishes) angling effort seems to be considerably less responsive to changes in success. Demand functions and success “elasticities” for each fishery were used to estimate the decrease in net economic value associated with a pollution-induced reduction in angling success. The methodology may also apply to evaluation of measures which would increase angling success, such as investment in hatcheries.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[357:ASAAQD]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The feeding rate was estimated for yearling carp living in a small lake contaminated with low-level radioactive wastes. The amount of137Cs that must be ingested to maintain the equilibrium body burden of the carp was calculated from measured values for body burden, biological elimination rates, and assimilation factors. The radioisotope was ingested by the fish as an integral part of its food items. The amount of food consumed was estimated by measuring the concentration of137Cs in the food items. An age and growth study and the weight-length relationship are given for the carp. The estimate of the average daily food intake was 5.36 g wet weight (3.9% of mean body weight) consisting of 2.4 g detritus and 1.6 g algae for maintenance, and 0.82 g detritus and 0.54 g algae for growth. On an energy basis, 3.7 kcal were consumed for maintenance and 1.3 kcal for growth. Net and gross food conversion factors were 3.18 and 12.55, respectively, and the ecological growth efficiency was 0.08.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[363:FROCEB]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Studies were made during 1964 and 1965 on the reproductive biology of the carp in selected marsh areas of Lake St. Lawrence. Male and female carp matured at ages III and IV, and IV and V, respectively. The sex ratio of males to females was 1.8:1. Spawning occurred from 18 May to 26 June in 1964, from 16 May to 1 August in 1965. Spawning did not occur below 17 C, reached an optimum activity at 19 to 23 C, decreased above 26 C, and ceased at 28 C. Major environmental factors affecting spawning and survival of eggs were water temperature and water level. Spot poisoning of marsh areas in September 1965 revealed a substantial survival of young-of-the-year carp hatched at various times during May, June, and July.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[372:RBOTCC]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

The lowest 2.4 miles of a small, unfished tributary of the St. Joe River was treated with rotenone in July 1964. Four species of fish, Salmo clarki (369 fish), Salvelinus fontinalis (2,361 fish), Cottus confusus (3,513 fish) and Cottus rhotheus (161 fish), formed the total population. The relative and absolute numbers and weights of S. clarki increased upstream whereas those of S. fontinalis increased downstream. In contrast, C. confusus was about evenly distributed and C. rhotheus was present in just the downstream 0.3 mile. With few irregularities, the mean lengths of the three most abundant species increased in an upstream direction.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[381:IODAMA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Larvae of bloaters (Coregonus hoyi) were sampled systematically in southeastern Lake Michigan, off Saugatuck, Michigan, from 9 April to 22 August 1964; limited additional sampling was done on 15 October. All collections were made with a 1-m plankton net of 0.66-mm mesh. A standard series of samples consisted of oblique tows for each 10-fathom (sometimes 5-fathom) stratum over bottom depths from 5 to 50 fathoms by 5-fathom intervals. Some additional oblique tows were made at 60, 70, 80, and 88 fathoms, and a single day-night series of horizontal tows was made at 40 fathoms.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[388:SADDOL]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Passage of upstream migrant sockeye salmon (Oncorhynchus nerka) and chinook salmon (O. tshawytscha) through the three pool-and-weir type fish ladders at Rock Island Dam on the Columbia River was controlled to a large extent by the proportion of the total flow discharged through the turbines and also by the location of the open spillway gates with respect to the ladders. At intermediate river discharges (140,000 through 300,000 ft3/sec) it was demonstrated conclusively that the fish's preference for either the right or center ladders could be controlled by spilling adjacent to these ladders. Response to the attraction spill was rapid. Attraction of sockeye was dependent not only upon spill position but also upon the tailwater elevation at the ladder entrance. The statistical analysis of fish behavior in an experimental choice situation is discussed in some detail, particularly the use of Chi-square and analysis of variance methods.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[397:SMTGMS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor

摘要:

Natural-colored brook, brown, and rainbow trout (12 to 15 months of age) have been obtained within 1 to 2 months by dietary administration of extracts of fresh raw crayfish to low-pigmented fish. It was shown by thin-layer chromatography and spectral studies that the crayfish xanthophylls present in the diet are essentially those deposited in the skin, fins, and flesh of the trout fed. As little as 30 to 50 meg of xanthophylls in the skin will produce average natural colors in rainbow and brown trout and 50 to 100 meg in brooks 14–16 months old.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1966)95[408:NCOTUX]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1966

数据来源: Taylor