Biology of the Redtail Surfperch (Amphistichus Rhodoterus) from the Central Oregon Coast
Biology of the Redtail Surfperch (Amphistichus Rhodoterus) from the Central Oregon Coast

Author: Donald E. Bennett

Publisher:

Published: 1977

Total Pages: 32

ISBN-13:

DOWNLOAD EBOOK

Data on certain aspects of the life history of the redtail surfperch were collected along the central coast of Oregon, from April 1967 through April 1969. Annulus formation occured during February through June, usually earlier in young than in older fish. Mating occurred from late December to early January, and the young were born from July through September. The number of embryos per female ranged from 1 to 39 (mean 13.3) and increased linearly with the length and weight of the females. Food of the fish from the surf zone included crustaceans (by far the most important group in both frequency of occurrence and total volume) and (in order of decreasing importance) fishes, mollusks, and polychaetes. Parasites of the redtail surfperch were immature nematodes (Anisakinae) ; the digenetic trematode Genitocotyle acirra; the monogenetic trematode, Diclidophora sp.; and the copepods, Caligus sp., Clavella sp., and Argulus catostomi.

Acute Toxicity of Six Forest Insecticides to Three Aquatic Invertebrates and Four Fishes
Acute Toxicity of Six Forest Insecticides to Three Aquatic Invertebrates and Four Fishes

Author: Herman O. Sanders

Publisher:

Published: 1983

Total Pages: 12

ISBN-13:

DOWNLOAD EBOOK

Technical grade and field formulations of six experimental forest insecticides -- methomyl, carbaryl, aminocarb, trichlorfon, fenitrothion, and acephate -- were tested for acut toxicity against three species of aquatic invertebrates, (a daphnid, an amphipod, and larvae of a midge), and four species of fish (bluegill, rainbow trout, fathead minnow, channel catfish). Five of the six insecticides were highly toxic or extremely toxic to the daphnid, amphipod, and midge larvae. The sixth insecticide, acephate, was not toxic to invertebrates at concentrations up to 50 mg/L. Five of the insecticides ranged from highly toxic (methomyl to channel catfish) to relatively non-toxic (trichlorfon to fathead minnows); the sixth, acephate, was only slightly toxic to the fishes tested.

Toxicity of Three Herbicides (butyl, Isooctyl, and Propylene Glycol Butyl Ether Esters of 2,4-D) to Cutthroat Trout and Lake Trout
Toxicity of Three Herbicides (butyl, Isooctyl, and Propylene Glycol Butyl Ether Esters of 2,4-D) to Cutthroat Trout and Lake Trout

Author: D. F. Woodward

Publisher:

Published: 1978

Total Pages: 12

ISBN-13:

DOWNLOAD EBOOK

Two formulations of the herbicide 2,4-D (2,4-dichlorophenoxyacetic acid) - the butyl ester (BE) and the propylene glycol butyl ether ester (PGBEE) -- had 96-h LC50's to cutthroat trout and lake trout ranging from 490 to 1,200 microgram/liter in static tests. A third formulation -- the isooctyl ester (IE) -- was not toxic to cutthroat trout or lake trout at concentrations below 60.000 microgram/liter. The butyl ester (2,4-D BE) was slightly more toxic than 2,4-D PGBEE, and the toxicity of both esters increased as water temperature decreased.

Ecology of Larval Fishes in Lake Oahe, South Dakota
Ecology of Larval Fishes in Lake Oahe, South Dakota

Author: William Roland Nelson

Publisher:

Published: 1980

Total Pages: 24

ISBN-13:

DOWNLOAD EBOOK

The time and location of spawning, food and larvae, and habitats used as nursery areas by young-of-the-year fishes were studied from 1972 to 1975 in South Dakota waters of Lake Oahe, a main stem Missouri River reservoir. Sampling locations were in the tributary rivres -- the Grand Moreau, and Cheyenne -- and their embayments. Year-class strength of river-spawning species was strongly correlated with river flow rates during the spawning season. Success of reservoir-spawning species was primarily dependent on above-average water levels, which inundated terrestrial vegetation to provide a substrate for egg deposition and cover for larvae. Preserving adequate streamflow and enhancing reservoir shoreline areas by managing water levels, seeding vegetation, and eliminating grazing alongshore would probably ensure adequate reproduction of most areas.

Changes in Distribution of Trout in Great Smoky Mountains National Park, 1900-1977
Changes in Distribution of Trout in Great Smoky Mountains National Park, 1900-1977

Author: George Alan Kelly

Publisher:

Published: 1980

Total Pages: 16

ISBN-13:

DOWNLOAD EBOOK

Significant changes have occurred in the distribution of trout in streams of Great Smoky Mountains National Park since 1900. By the mid-1970's the original range of the native brook trout had been reduced by about 70% and the species was relegated to suboptimal habitat in head water streams. Most of the stream sections lost by brook trout became the territory of the introduced rainbow trout, which in 1977 occupied about 80% of the Park waters. After 1950, brown trout introduced in State waters outside the Park established reproducing populations in some 50 miles of stream formerly occupied only by rainbow trout. If current trends continue, the recovery of brook trout in Park water may be difficult, if not impossible, and brown trout may occupy much of the territory now held by rainbow trout.

Neuroendocrine Mediation of Photoperiod and Other Environmental Influences on Physiological Responses of Salmonids
Neuroendocrine Mediation of Photoperiod and Other Environmental Influences on Physiological Responses of Salmonids

Author: Hugh A. Poston

Publisher:

Published: 1978

Total Pages: 20

ISBN-13:

DOWNLOAD EBOOK

Manipulation of photoperiods, combined with modifications by other environmental conditions such as temperature and salinity, can alter growth, smoltification, and sexual maturation of salmonid fishes by way of a neuroendocrine pathway. The extent of responses of salmonids to environmental changes, however, is restricted by circadian endogenous metabolic rhythms that cannot be completely overcome by external factors. The success of the manipulation of photoperiod depends primarily on four factors: the daily length and the duration of the light treatment; the season and time of day during which fish are exposed to light; the age, sex, size and species of fish; and the type of physiological response under consideration. Although gaps remain in the available information, salmonids apparently need systematically changing, intermittent periods of darkness for optimum long-term stimulation of growth, reproduction, and migration.

Monthly Catalog of United States Government Publications
Monthly Catalog of United States Government Publications

Author: United States. Superintendent of Documents

Publisher:

Published: 1977

Total Pages: 1092

ISBN-13:

DOWNLOAD EBOOK

February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Proximate Composition and Caloric Content of Eight Lake Michigan Fishes
Proximate Composition and Caloric Content of Eight Lake Michigan Fishes

Author: Donald V. Rottiers

Publisher:

Published: 1982

Total Pages: 16

ISBN-13:

DOWNLOAD EBOOK

The proximate composition (percentage lipid, water, fat-free dry material, ash) and caloric content of eight species of Lake Michigan fish were measured: lake trout, coho salmon, lake whitefish, bloater, alewife, rainbow smelt, deepwater sculpin, and slimy sculpin. Except for alewives, proximate composition and caloric content did not differ significantly between males and females. Although the caloric content of all species varied directly with lipid content and inversely with water content, an increase in lipid content did not always coincide with a proportional increasein caloric content when other components of fish composition were essentially unchanged. This observation suggests that the energy content of fish estimated from the proximate composition by using universal conversion factors may not necessarily be accurate.