ISSN:0002-8487    

DOI:10.1577/00028487.1949.10492643

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1949.10492658

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1949.10492659

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

A questionnaire survey of the various states was made in June of 1946 to determine the current trends in fishery programs. Trout states total 31, with 246 hatcheries producing 203,546,000 fry and fingerlings and 18,081,000 creel-sized trout. The trend is to more creel-sized trout. States take 194,000,000 eggs themselves and obtain 98,375,000 trout eggs from other sources. A majority of states classify results of fry plantings as poor and of creel-sized plantings as good.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[13:CTISFP]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

Winterkill of fish in southern Michigan lakes during 1944–45 provided an opportunity to study the effect of different degrees of oxygen depletion on the extent of mortality and survival of several common species of fishes. Eleven lakes were investigated. Several inches of snow cover remained on the lakes from December 11 to February 15. This abnormal persistence of snow cover was accompanied by oxygen depletion in some of the lakes to mid-winter lows occurring about February 14. The maximum concentration of oxygen in vertical series taken at about the time of greatest depletion ranged from 0.2 to above 5.0 p.p.m. in the different lakes. Where oxygen depletion was severe this maximum occurred only in a thin stratum immediately beneath the ice. Heavy winterkills occurred only in those lakes in which the dissolved oxygen was depleted to approximately 0.6 p.p.m. or less. The mortality was greatest among bluegills and largemouth bass, apparently 100 percent in some lakes. Among the pumpkinseeds, mud pickerel, northern pike, chub suckers, bullheads, and golden shiners there was a large rate of survival even in lakes where the oxygen was reduced to 0.3 or 0.2 p.p.m. No complete kill of all fish in a lake was encountered.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[23:RODOTW]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

Brook, brown, and rainbow trout were fed diets containing various levels of thiamin, pantothenic acid, and riboflavin. After a period trout were killed and their livers analyzed for the vitamin content. The diet causing maximum storage was considered to be the tentative requirement of the trout. No difference was found between the requirement of three species of trout and no difference was found between the two temperatures at which the experiment was run. The tentative requirement for riboflavin was established at between 0.44 and 0.68, pantothenic acid between 0.97 and 1.25, and thiamin between 0.150 and 0.186 milligrams per kilogram of body weight per day. The maximum storage was found to be between 18 and 20 micrograms of pantothenic acid, 15 and 16 micrograms of riboflavin, and 3.5 and 4.5 micrograms of thiamin per gram of liver tissue. A difference was found between the two series with respect to the level of stored pantothenic acid and thiamin. This difference may be a function of age or size. The limitations of this type of study are discussed.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[34:TVBROT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

Various combinations of largemouth bass, bluegills, golden shiners, gizzard shad, and Gambusia were stocked in 0.25-acre experimental ponds. The ponds were fertilized with inorganic fertilizer. After 1 or 2 years the ponds were drained and the fish counted and weighed. The bluegill proved the most desirable forage fish, although it did not result in the highest bass production in these experiments. It appeared to offer promise of the highest sustained yield of bass over a period of years. Golden shiners gave higher bass production for a 1- to 2-year period, but could not maintain high production over a longer period. Goldfish could not be used with bluegills because the latter ate goldfish eggs and prevented reproduction. Goldfish also were not satisfactory when used with bass only, because many young grew too large for bass to eat and ate their own eggs, thus preventing further reproduction. Gizzard shad produced a high poundage of bass, but the young rapidly grew too large for bass to eat and overcrowded the ponds. As a result, they stopped reproducing and at the same time reduced bluegill production. Gambusia were unsatisfactory as forage fish because bass eliminated them almost entirely from ponds in a few months.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[46:EWCOLB]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

The average size for the various age groups is presented for seven Michigan fishes: the bluegill (Lepomis m. macrochirus), yellow perch (Perca flavescens), pumpkinseed (Lepomis gibbosus), rock bass (Ambloplites r. rupestris), largemouth black bass (Micropterus salmoides), smallmouth black bass (Micropterus d. dolomieu), and the black crappie (Pomoxis nigro-maculatus). Ages were determined for 25,723 specimens. Only two species showed consistent sex differences in growth rate. The female yellow perch grew more rapidly than did the males, and the male rock bass were consistently larger than the females of corresponding age.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[63:TROGAS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

To determine the most effective dosage of sulfamerazine in the treatment of furunculosis in brook trout, two experiments were run.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[82:DOSITT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

The kingfisher is the most common and universally distributed bird predator of fish in Michigan. Its principal migration routes are along the Great Lakes shores. Nesting territories are established along streams and lake shores; they are usually larger in the former than in the latter. The kingfisher is diurnal in its feeding with three peaks of activity–morning, afternoon, and early evening. First feeding of fledgelings is on insects; this food is followed by crayfish, then by fish. Fish eaten average about 2.3 inches in length and at fish hatcheries are mostly the species being propagated. On natural waters the food consists mostly of non-food and non-game fishes and crayfish. Predation pressure varies with season and within season according to weather, nest distribution, and environmental suitabliity of waters for feeding activity. Because of their feeding proclivities, it is undesirable to have kingfishers about fish hatcheries and rearing stations. At present, general control on natural waters is not biologically justified.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1946)76[97:TEBKMA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor