Download or read book Biology of the Pile Perch Rhacochilus Vacca in Yaquina Bay Oregon written by Paul Gordon Wares and published by . This book was released on 1971 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth, reproduction, food habits, and parasites of pile perch were investigated in Yaquina Bay, Oregon between April 1966 and July 1967. The research disclosed that pile perch live at least 10 years. Males and females of given ages are close to the same size up to age IV, after which females are increasingly larger than males. The diet varies between seasons and localities. Pile perch are carnivorous feeders, obtaining food from the bottom or protruding surfaces in the littoral zone. Principal foods are barnacles, mussels, the bay clams, crabs, mud shrimp and tube dwelling amphipod. None of the pile perch examined was heavily parasitized. Infestations of gill copepods vary seasonally.
Download or read book Biology of the Pile Perch Rhacochilus Vacca in Yaquina Bay Oregon written by Paul G. Wares and published by . This book was released on 1971 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biology of Pile Perch Rhacochilus Vacca in Yaquina Bay Oreg with List of References written by and published by . This book was released on 1971 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biology of the Pile Perch Rhacochilus Vacca written by Paul Gordon Wares and published by . This book was released on 1968 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data were gathered on the life history of the pile perch (Rhacochilus vacca) from Yaquina Bay, Oregon, between April, 1966, and July, 1967. Pile perch feed on the bottom and consume mostly molluscs, barnacles and decapod crustaceans. Food habits varied among seasons and locations within the bay, whereas the diet of young-of-the-year perch differed only slightly from the diet of older fish. Mating occurred from October to January and the young were born from mid-July to mid-August. Timing of the reproductive cycles coincided in the two years observed. The gestation period is approximately six months. Fecundity was positively correlated with lengths of fish. An intraovarian mortality rate of 4.8 percent was estimated. instantaneous daily growth rates in weight of 0.0606 for embryos and 9.0093 for newborn fish were estimated. About one-third of the females were mature at age III and nearly all were mature at age IV. Longevity exceeded ten years and maximum attainable lengths (100) of 432 and 490 mm (TL) were estimated for males and females, respectively. Females grew slightly faster than males. Few perch of age classes I and II were captured. Females generally occurred higher (upstream) in the bay than males. Pile perch were commonly host to the copepods, Clavella and Lepeoptheirus; the nematode, Cucullanus;and metacercariae of bucephalid trematodes. The rate of copepod infestations varied seasonally.
Download or read book Biology of the Redtail Surfperch Amphistichus Rhodoterus from the Central Oregon Coast written by Donald E. Bennett and published by . This book was released on 1977 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
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 Species Profiles written by Ronald A. Fritzsche and published by . This book was released on 1989 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biological Studies on the Hemoflagellates Cryptobia Cataractae and Cryptobia Salmositica written by R. E. Putz and published by . This book was released on 1972 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies on two hemoflagellates of fish were carried out to determine biological parameters: host range, vector relations, in vivo culture, in vitro culture, pathogenicit, and cryogenic preservation.
Download or read book Selected Research Publication Series of the U S Fish and Wildlife Service 1889 1985 written by and published by . This book was released on 1987 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: A bibliography comprising annotated citations of 2037 scientific and technical publications from ten series issued by the U.S. Fish and Wildlife Service. Includes a six-page introduction containing a history of the Service and a description of the research and development series.
Download or read book Collected Reprints written by Southwest Fisheries Center (U.S.) and published by . This book was released on 1971 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Changes in Young of the year Fish Stocks During and After Filling of Lake Oahe an Upper Missouri River Storage Reservoir 1966 74 written by Fred C. June and published by . This book was released on 1976 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abundance increased and was highest in the lower third of the reservoir while it was filling, whereas it decreased and was generally highest in the upper two-thirds of the reservoir after it was filled. Abundance of species produced in littoral areas was greater wwhile the reservoir was filling -- particularly in years when spring water levels covered vegetation, fluctuated little, and were maintained through May or longer -- than after the reservoir was filled.
Download or read book Changes in Distribution of Trout in Great Smoky Mountains National Park 1900 1977 written by George Alan Kelly and published by . This book was released on 1980 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ecology of Larval Fishes in Lake Oahe South Dakota written by William Roland Nelson and published by . This book was released on 1980 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Food of Alewives Yellow Perch Spottail Shiners Trout perch and Slimy and Fourhorn Sculpins in Southeastern Lake Michigan written by LaRue Wells and published by . This book was released on 1980 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stomachs of 1,064 alewives, 1,103 yellow perch, 246 spottail shiners, 288 trout-perch, 454 slimy sculpins, and 562 fourhorn sculpins from Lake Michigan were examined for food contents. Fish were sampled primarily from March to November and nearly all were caught at the bottom in the southeastern part of the lake near Saugatuck, Michigan. Pontoporeia was the most commonly reprented food item in the stomach contents of the fish examined, with immature midges, Mysis (a type of freshwater shrimp), copepods, cladocerans, fingernail clams and crayfish also being represented. Different species consumed different proportions of foods. Zooplankton was the principle food of alewives and spottail shiners, but was also consumed in small quantities by yellow perch and trout perch. Mysis was important to fourhorn sculpins, in addition to Pontoporeia. Immature midges were a major portion of spottail shiners and trout perch, also being consumed by alewives. Fish were often the most important food of yellow perch in the largest size category. Crayfish were a sizable portion of the diet of yellow perch on rocky bottoms, but sparingly on smooth bottoms. Spottail shiners also ate substantial numbers of fingernail clams.
Download or read book Neuroendocrine Mediation of Photoperiod and Other Environmental Influences on Physiological Responses of Salmonids written by Hugh A. Poston and published by . This book was released on 1978 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Gonad Development Fecundity and Spawning Season of Largemouth Bass in Newly Impounded West Point Reservoir Alabama Georgia written by Tom J. Timmons and published by . This book was released on 1980 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The percentage body weight contributed by the ovaries and frequency distributions of ovarian egg diameters were reliable indicators of the spawning season of largemouth bass, in West Point Reservoir in 1977.
Download or read book Toxicity of Three Herbicides butyl Isooctyl and Propylene Glycol Butyl Ether Esters of 2 4 D to Cutthroat Trout and Lake Trout written by D. F. Woodward and published by . This book was released on 1978 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
