摘要:

A 10.3-hectare impoundment at Auburn, Alabama, was stocked with bluegill (Lepomis macrochirus), redear sunfish (Lepomis microlophus), largemouth bass (Micropterus salmoides), black crappie (Pomoxis nigromaculatus), and fathead minnow (Pimephales promelas) at densities of 1,852, 617, 247, 247, and 2,470 per hectare, respectively, during December, 1965 to June, 1966. When the impoundment was opened to public fishing in May 1967, half the shoreline and 90% of the impounded area were closed to fishermen. Compared with typical non-sanctuary ponds under similar fishing pressures, the initial catch rates of bass and sunfish were lower in the sanctuary pond. The presence of the sanctuary did not reduce the total catch per hectare, but the catch was spread over a longer fishing season.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<441:SEOASO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The potential impact of commercial bait harvest from small streams was studied in Rich Creek, West Virginia. A mail survey and personal interviews of bait dealers in the mountain areas of this state established typical harvest pressures exerted by commercial operations. Bait fish and crayfish in 50-m sections of Rich Creek were harvested three times every two weeks from May 15 until September 15, 1973, via seine and minnow traps. Treatments consisted of no harvest, a harvest simulating a typical bait dealer, and a harvest pressure twice that of a commercial dealer; all treatments were in triplicate. The effects of the harvests were determined by comparisons over time within treatments, comparisons between treatments and comparisons with final population indices. No significant differences in these comparisons were found to occur for the bait species or for the game fish species inhabiting the study sections. The different harvesting pressures did not appear to affect the densities of the bait and game fish populations.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<446:EOHABS>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Groups of minnows accepted home ranges in aquarium tanks and did not stray from their home area when an exit route leading to a similar area was available. Minnows actively horned when displaced in a reciprocal transfer between two ranges in the tank. The degree of homing depended on the length of time the minnows had been kept in their home areas initially, and homing was well established after five weeks.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<454:EOHISO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Upstream migrating adult steelhead trout (Salmo gairdneri), transported downstream, hooked, and played to exhaustion, returned to their target spawning stream equally as well as fish just transported and released. The number of fish returning to their home stream was inversely related to the distance transported and appears to be directly related to the number of days remaining before spawning.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<458:EODHAR>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Eight mixtures of sand and gravel were tested in experimental troughs, to simulate hatching conditions in coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri) redds. Fry were released into perforated, open-ended chambers below the gravel surface. An inverse relationship was found between the quantity of fines and emergent survival. Mean emergent survival for coho salmon ranged from 96% in the control mixture to 8% in 70% sand (less than 3.3 mm diameter). Mean emergent survival for steelhead ranged from 94% to 18%, respectively. Premature emergence of coho fry was related to higher concentrations of fines. These premature fry were smaller, and retained more yolk than fry emerging at normal times.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<461:SEOGMO>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Rainbow trout fry spawned in an intermittent stream had a diel periodicity in downstream movement that was highly correlated with discharge. Shortly after fry emerged in mid-July 1973, Kiln Meadow Tributary of Sagehen Creek began to dry up and fry began to move downstream, primarily during the day. After rains, when the water level remained high (5 to 8 liters/s) without diel fluctuations, few fry were captured in the trap.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<467:DMORTF>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Progeny from inlet-spawning cutthroat trout (Salmo clarki) in Yellowstone Lake move downstream and progeny from outlet-spawning adults move upstream to enter the lake to rear. I examined the role of genetic control, rheotactic acclimation (acclimating swim-up fry to water current and no water current), constant and fluctuating water temperatures, and changing water source in directing migrations of Yellowstone Lake fry by testing them in simulated stream channels.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<474:FIGCIL>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The majority of juvenile alewives (Alosa pseudoharengus) migrating seaward from Hamilton Reservoir, North Kingstown, Rhode Island, did so on less than 10 per cent of the total days of their period of residence in freshwater during 1970, 1971, and 1972. Extensive migration occurred following increases in pond outflow, abrupt water temperature declines, and/or precipitation. Daily patterns of movement were unimodal, with maximum movement occurring in mid-afternoon. Groups of fish migrating downstream during periods of extensive migration were random portions of the pond population. Growth rates varied in different parts of the drainage system. A model of the behavioral basis for seaward migration of juvenile alewives from ponds and lakes is presented.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<483:MBAGOJ>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The response of juvenile alewives to water currents in an experimental chamber was examined. Fish showed greater movement from the center of the chamber when water was flowing then when under static conditions. Fish oriented strongly to currents, and their direction of movement may have been influenced by current velocity. Responses to currents were similar in fresh and seawater.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<494:TROJAT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The validity of scale analysis for aging tigerfish, Hydrocynus vittatus Castelnau, was assessed by examining the timing and cause of check formation on scales from fish collected in Lake Bangweulu, Zambia. Discontinuities in circuli that appeared to be valid annuli formed on all scales in September when water temperature was rising rapidly after dropping to 18 C. Spawning checks formed on scales of some fish in January. Male and female tigerfish grew at similar rates. Some females reached an age of 11 years but male tigerfish, which matured one and sometimes two years earlier, seldom lived longer than 4 years.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1975)104<499:AFAGOT>2.0.CO;2

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor