摘要:

Schools of juvenile Pacific ocean perch, Sebastes alutus, at four coastal fiord sites in southeastern Alaska were sampled by trawling. Younger juveniles (ages I and II) were over rougher substrate than older juveniles (ages III-V); both age groups were at shallower depths than adults. Lengths of juvenile perch varied between and within geographic areas, but the pattern of variation was not consistent. The most important food items were copepods and euphausiids; younger juveniles fed more on copepods and older juveniles more on euphausiids. Feeding activity was minimal in late winter and early spring. The relative strength of year classes fluctuated widely. Some juvenile perch are shown to become demersal by age I, and the hypothesis of a 2-3-year early pelagic existence is rejected.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<191:JLOPOP>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Examination of the digestive tracts of 588 blackcheek tonguefish, Symphurus plagiusa, during 1973 and 1974 indicated a primarily benthic feeding habit. Mollusks and various crustaceans were the most common identifiable constituents of the diet during all times of the year in fish of all sizes above postlarvae in both rivers and sounds in Georgia estuaries. Sand grains were present in about half of the fish.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<202:FHOGEF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The ecology of mountain whitefish (Prosopium williamsoni) in the upper Sheep River was studied during 1972 and 1973. Mountain whitefish spawned from late September to mid-October in shallow, fast, midstream areas. The number of spawning fish on each spawning site was small (two to 20 fish per site). Absolute fecundity (eggs/fish) increased as the females became older; however, relative fecundity (eggs/g of fish) remained comparatively stable for all age classes. The linear regression of absolute fecundity (Y) on fork length (X, in mm) is described by the formula: Y = 4347.6 + 50.7 (X – 301.5). Growth is rapid except in the older age classes of 7 and 8. The weight (Y, in g) length (X) relationship (sexes combined) is described by the formula: log Y = 2.1967 + 3.2108 (log X – 2.3710). The relationship of body (Y) to scale (X) growth is described by: log Y = 2.0891 + 0.9542 (log X – 2.4367). Recruitment into the population of the upper Sheep River appeared to be at 3 years of age with an annual natural mortality rate of approximately 33% on 3-year-old and older mountain whitefish. The diets of mountain whitefish consisted primarily of dipterans, ephemeropterans, trichopterans, and terrestrial invertebrates.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<208:OOTAGR>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The red shiner Notropis lutrensis is reported from North Carolina for the first time. This record, the first east of the Appalachian mountains, represents a range extension of approximately 850 km. This population probably originated from the escape or release of aquarium or bait fish.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<220:OOTRSN>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Elephant Butte Lake is a large warmwater impoundment of the Rio Grande in southwestern New Mexico. Thirteen of 28 species of fish present are relatively abundant. Nine of the 13 species are game fishes; one is forage; and river carpsucker (Carpiodes carpio), smallmouth buffalo (Ictiobus bubalus), and carp (Cyprinus carpio) make up a large rough or commercial fish group. Buffalo were exploited heavily, carp lightly, and carpsucker were unexploited from 1963-1972. Estimates of live-weight biomass production were 22,400 kg of carpsucker in 1967, 311,850 kg of buffalo in 1966, and 49,500 kg of carp in 1969. Standing crops changed from 29,500 kg to 30,200 kg of carpsucker, 275,400 kg to 252,700 kg of buffalo, and 40,200 kg to 39,600 kg of carp during the year. Distribution of production among age groups is discussed in relation to exploitation rates and reproductive success of each species. Annual production cycles are discussed in terms of 0.1-yr time intervals.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<222:POROCF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The desirability of incorporating fishermen preferences into management decision making was identified. A questionnaire survey technique based on a random sample of residents was developed to obtain unbiased assessment of angler preference. The survey technique was tested in the Owasco Lake (New York) watershed.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<232:UOQSIF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Nine 0.04-hectare ponds of the Alabama Agricultural Experiment Station were used to evaluate growth differences among northern largemouth bass, Micropterus salmoides salmoides (Lacepede), Florida largemouth bass, Micropterus salmoides floridanus (Lesueur), and their hybrid. Salmoides grew faster than floridanus or the hybrid during the first summer of life. Since the environments were similar the differences in growth rates were attributed to genetic factors. The first year growth, therefore, is not the factor which contributes to the larger adult size of the Florida largemouth bass. Angling records from four other ponds indicated that floridanus was significantly more difficult to catch than salmoides. The difference is probably great enough to significantly affect the catch in heavily fished bodies of water.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<240:GCOTNA>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Largemouth bass (Micropterus salmoides) were studied in an effort to determine if a repressive factor or predation by sunfishes (Lepomis sp.), or both, caused failure of bass reproduction in ponds crowded with sunfishes. In addition, we observed anosmic bass to determine if lack of olfaction would allow bass to spawn, in the event that a repressive factor operating through the sense of smell was the inhibitor. However, neither a repressive factor nor sunfish predation was believed to be responsible for lack of reproduction. Lack of reproduction was apparently associated with a physical factor that in some way interrupted normal bass breeding activity.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<244:ROLBRT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A 0.2-hectare channel catfish, Ictalurus punctatus, catchout pond was operated for three fishing seasons to develop techniques beneficial to both angler and pond owner. During the first two seasons catfish were cage-reared to catchable size in the catchout pond and periodically released to replace fish caught by anglers. The larger and/or faster-growing catfish were more vulnerable to capture by hook-and-line angling than the smaller and/or slower growing individuals.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<247:TYOEWA>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Growth of age group 0 yellow perch (Perca flavescens) and walleye (Stizostedion vitreum vitreum) was studied when temperature and light conditions (photoperiod) were varied. Fish, fed formulated dry pellets, were kept for 14 weeks at 16 and 22 C in combination with 8- and 16-hour photoperiods.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1976)105<254:EOTALO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor