摘要:

The method of ageing bluegills by their scales was validated for two Texas reservoirs. Annulus formation occurred from January through July (peak February-April) in Lake Bastrop and from January to June (peak in March and April) in Lake Nasworthy. Female bluegills grew faster than males in both lakes. Little or no growth occurred from October-November through February. Growth of bluegills in Lakes Bastrop and Nasworthy was above average for the first two years when compared to the growth of bluegills in other lakes reported in the literature. The length-weight regression equations for bluegills from Lake Bastrop and Lake Nasworthy were: log W = −4.46319 + 3.01844 log L and log W = −4.64744 + 3.13263 log L, respectively.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<506:AAGOBL>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Yellow bass age and growth data were obtained from 202 fish collected in Lake Poygan, Wisconsin, a 5,707-hectare widening of the Wolf River, during October, 1963 and winter of 1963-64. The fish length-scale length relationship was L = 15 + 1.529 (R). No significant difference in growth between sexes was found. The growth of Lake Poygan yellow bass was greater than that reported from most areas. All fish were mature at age-group III. The length-weight relationship was log W = −4.0289 + 2.7000 log L, where W = weight in g and L = total length in mm.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<513:AAGOTY>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Notropis roseipinnis is a small southern minnow inhabiting small tributary streams in the Gulf Coastal Plain typified by rapidly fluctuating environmental conditions. The reproductive season extends from late March into August or early September in the Jourdan River system, Hancock County, Mississippi. The sex ratio was not different from 1:1 and the mean sizes of males and females were similar. Most fish were mature by about 30 mm standard length (SL). The number of mature ova was correlated with the size of the female, ranging from 50 to 293 for females 29.6-46.6 mm SL. There were significant differences in the number of mature ova with time. Two peaks were indicated, one at the beginning of the reproductive season and one in the latter half. The mean diameter of mature ova (0.65-0.85 mm, mean 0.77) was not significantly correlated with fish length.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<516:TELHOT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

As a result of one day of high winds, large quantities of eggs of yellow perch, Perca flavescens, were washed ashore at a number of locations in the windward shoreline of Oneida Lake. A single large windrow, just downwind from a major spawning area, contained almost one percent of the estimated egg potential of the lake's perch population. Damage to the dislodged egg masses appeared most severe in areas with rubble bottoms.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<524:EOHWOE>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Lake Francis Case, a 356-km2Missouri River reservoir, is drawn down each fall to hold water released from upstream for winter power generation. The customary drawdown of 10-12 m in 1953-70 was reduced to 6-7 m in 1971-73. Benthos samples collected from 1966 to 1973 indicated that abundance of benthic organisms in May along two transects (to depths of 10.5 and 15 m) increased more than threefold after the drawdown was reduced; abundance in September did not increase. May increases were most evident for five burrowing forms: chironomids, Hexagenia, Caenis, oligochaetes, and ceratopogonids.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<526:EOARFD>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The amount of daily invertebrate drift in the Matamek River varied both seasonally and down the length of the river. From June to September 1973, the volume of drift was about eight times greater in June than in August. Filter feeding insects and planktonic crustacea were more numerous at the upstream station near a lake, than at a station 4 km downstream. Larvae of net-spinning Trichoptera were twice as abundant at the upstream station, and simuliid larvae four times as abundant. Numbers of zooplankton closely followed changes in water level, and were highest in early summer and the fall, and were lowest in August. The salmonid bio-mass was at least four times greater at the upstream station than the lower one, most likely the result of a greater abundance of insect larvae suitable as food nearer the lake.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<529:TRBIDA>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Food habits of an Amargosa pupfish {Cyprinodon nevadensis amargosae) population inhabiting a thermal stream were examined at monthly intervals from January 1972 to April 1973. Little variation in foods eaten during the year was observed in the 218 specimens examined. The diet was almost entirely a mixture of blue-green algae and detritus. Invertebrates were only a minor component due to their scarcity in the stream. The smallest fishes consumed some invertebrates but this habit changed as the relative length of the digestive tract rapidly increased.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<536:FHOTAP>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Pinnixa faba and Pinnixa littoralis ranked third and seventh, respectively, in the list of major food items in the diet of young-of-the-year copper rockfish from an artificial reef in South Humboldt Bay, California. Previously, P. faba and P. littoralis have been described as being primarily internal commensals of marine pelecypods and as such were not considered an important food of finfish.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<539:PCITDO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A qualitative and quantitative investigation of the food habits of the brown bullhead, Ictalurus nebulosus (LeSueur), was conducted between June and September, 1968, in the acid-polluted Monongahela River, West Virginia, and in Doe Pond, a small relatively pollution-free subimpoundment of the Tygart River Reservoir, West Virginia.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<541:FHOINI>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Triplicate lots of young Atlantic salnon (Salmo salar) were fed a diet containing graded levels of supplemental inorganic phosphorus. The basal diet, containing mainly dehulled soybean meal and other plant materials, provided 40% crude protein, 0.7% phosphorus, 1.5% calcium, and 4,000 IU of supplemental cholecalciferol per kg of diet. Supplements of inorganic phosphorus significantly improved growth, feed utilization, and bone ash content. Inorganic phosphorus supplementation up to 0.6% of the diet increased growth rate and bone ash content; additions beyond this level had little further effect. This study suggests that when young salmon are fed diets containing 0.7% phosphorus from plant sources, the minimum requirement for supplemental inorganic phosphorus is approximately 0.6% of the diet.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<548:ROASFD>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor