Download or read book Some Chronic Effects of DDT on Cutthroat Trout written by Donald T. Allison and published by . This book was released on 1964 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects on cutthroat trout (Salmo clarki lewisi) of periodic exposure to different levels of DDT in bath and in food were determined over a 20-month period involving one spawning cycle. High dosages produced a marked increase in mortality, probably by reducing the resistance to nonspecific stressors; survivors fish in high-dosage lots were significantly larger than those in control and low-DDT lots. Intermediate and low dosages of DDT generally did not measurably affect mortality, growth, or reproductive potential, indicating that a threshold level exists around 0.1 p.p.m. monthly in contact form and around 0.3 mg. DDT per kg. of fish weekly in the diet for the toxic effects of DDT.
Download or read book Some Effects of DDT on the Guppy and the Brown Trout written by Susan Frances King and published by . This book was released on 1962 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Editor's note: This paper was prepared under the direction of Assistant Professor Kathryn M. Eschenberg, Mount Holyoke College and was accepted by the Faculty in partial fulfillment of the requirements for the degree of Bachelor of Arts with Honor, 1961. Despite certain limitations, described below, the paper (somewhat condensed from the original) has been accepted for publication because (1) it is an unusual and excellent study by an undergraduate, and (2) so little information is available on the subject treated. Biometricians may criticize the paper from the standpoint of small numbers and need for replication. One reviewer says: "One of the most interesting observations related to the apparent increase in resistance following exposure to effectively sublethal levels. Part of the increase, but likely only part, was due to the previous selective killing of weaker individuals. Good experimental procedure would require that this test be repeated, with parallel series of previously unexposed fish....There is need for a replicated study of numbers of young born to guppies held in DDT, especially because the numbers are so small." It is the Editor's hope that the limitations of the paper may stimulate further work in this important area.
Download or read book Chronic Effects of Methoxychlor on Bluegills and Aquatic Invertebrates written by Harry D. Kennedy and published by . This book was released on 1970 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significantly higher numbers of aquatic insects were sampled in treated ponds than in untreated, and insect numbers at high-treatment ponds were significantly higher than at low-treatment ponds. Chironomids were dominant and significatnly increased after a certain level of treatment. Chironomids comprised 74 percent of samples from high-treatment ponds, but only 43 and 42 percent respectively fro untreated and low-treatment ponds. Methoxychlor residues were not detectable in pond-bottom mud samples.
Download or read book Handbook of Acute Toxicity of Chemicals to Fish and Aquatic Invertebrates written by W. Waynon Johnson and published by . This book was released on 1980 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resource Publication written by and published by . This book was released on 1980 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Pathology of Fishes written by William E. Ribelin and published by Univ of Wisconsin Press. This book was released on 1975 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specific diseases. Lesions of organic systems. Chemical and physical agents of disease. Nutritional diseases. Neoplasia.
Download or read book Research Report written by U.S. Fish and Wildlife Service and published by . This book was released on 1964 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Report Bureau of Sport Fisheries and Wildlife written by United States. Bureau of Sport Fisheries and Wildlife and published by . This book was released on 1941 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Report written by and published by . This book was released on 1961 with total page 1358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Abstracts of Recent Published Material on Soil and Water Conservation written by and published by . This book was released on 1966 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstracts for Dec. 1954- issued in the Agricultural Research Service's series ARS-41.
Download or read book Ecological Perspectives of Wildlife Management written by and published by Ardent Media. This book was released on 1977 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Papers of the Bureau of Sport Fisheries and Wildlife written by United States. Bureau of Sport Fisheries and Wildlife and published by . This book was released on 1966 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Papers of the Bureau of Sport Fisheries and Wildlife written by and published by . This book was released on 1970 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Papers written by United States. Bureau of Sport Fisheries and Wildlife and published by . This book was released on 1970 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Papers of the U S Fish and Wildlife Service written by and published by . This book was released on 1980 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology of Daphnia in Bull Shoals Reservoir written by Richard L. Applegate and published by . This book was released on 1969 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Life histories of Daphnia galeata mendotae, D. retrocurva, D. parvula, D. ambigua, and D. schoedleri are compared with year class strength and food of threadfin shad in Bull Shoals Reservoir from 1965 to 1967. Maximum population density of daphnids was in April, May, and June. Populations declined to insignificant densities throughout the rest of the year. Declines coincided with the inclusion of Daphnia in the diets of threadfin shad smaller than 14 mm. Declines in the summer of 1967 coincided with both young shad predation and high Leptodora kindtii density. Population changes associated with declining year class strength of threadfin shad were an increase of the large D. schoedleri and Leptodora kindtii from nondetectable or trace densities to relatively large populations, and increase from nondetectable densities of daphnids in the summer to detectable densities, and a twofold to threefold increase in the summer standing crops of Bosmina longirostris.
Download or read book Chlorinated Hydrocarbons as a Factor in the Reproduction and Survival of Lake Trout Salvelinus Namaycush in Lake Michigan written by and published by . This book was released on 1981 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
