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Articles 2671 - 2700 of 2901

Full-Text Articles in Animal Sciences

Phyletic Coevolution Between Subterranean Rodents Of The Genus Ctenomys (Rodentia: Hystricognathi) And Nematodes Of The Genus Paraspidodera (Heterakoidea: Aspidoderidae) In The Neotropics: Temporal And Evolutionary Implications, Scott Lyell Gardner May 1991

Phyletic Coevolution Between Subterranean Rodents Of The Genus Ctenomys (Rodentia: Hystricognathi) And Nematodes Of The Genus Paraspidodera (Heterakoidea: Aspidoderidae) In The Neotropics: Temporal And Evolutionary Implications, Scott Lyell Gardner

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Coevolution was studied in six species of rodents of the genus Ctenomys and their parasitic nematodes of the genus Paraspidodera, collected in Bolivia. Representatives of the families Octodontidae and Caviidae were used as outgroups for the mammals, and nematodes from caviids were used as outgroups of the nematodes from ctenomyids. For the nematodes, quantitative and qualitative morphological characteristics of both males and females and electrophoretic characters of both sexes were used to generate phylogenetic hypotheses of evolutionary relationships of the OTUs occurring in hosts of different species. Concordance estimates of cladograms generated from biochemical-genetic and morphological data of the …


Introgression Of Coyote Mitochondrial Dna Into Sympatric North American Gray Wolf Populations, Niles Lehman, Andrew Eisenhawer, Kimberly Hansen, L. David Mech, Rolf O. Peterson, Peter J. P. Gogan, Robert K. Wayne Jan 1991

Introgression Of Coyote Mitochondrial Dna Into Sympatric North American Gray Wolf Populations, Niles Lehman, Andrew Eisenhawer, Kimberly Hansen, L. David Mech, Rolf O. Peterson, Peter J. P. Gogan, Robert K. Wayne

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Mitochondrial DNA (mtDNA) genotypes of gray wolves and coyotes from localities throughout North America were determined using restriction fragment length polymorphisms. Of the 13 genotypes found among the wolves, 7 are clearly of coyote origin, indicating that genetic transfer of coyote mtDNA into wolf populations has occurred through hybridization. The transfer of mtDNA appears unidirectional from coyotes into wolves because no coyotes sampled have a wolf-derived mtDNA genotype. Wolves possessing coyote-derived genotypes are confined to a contiguous geographic region in Minnesota, Ontario, and Quebec, and the frequency of coyote- type mtDNA in these wolf populations is high (> 500%). The …


Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration Dec 1990

Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration

Publications (WR)

The Lake Mead Fertilization Project is a research program designed to investigate the potential for using large-scale artificial fertilization to enhance the game fisheries of this reservoir through an increase in the population of threadfin shad, the system's primary forage species. A substantial decline in the population of largemouth bass, together with poor condition of adult striped bass, are the two major issues affecting the Lake Mead game fisheries. Both issues have been hypothesized to be a result of an inadequate amount of forage in the reservoir. Previous studies have in turn suggested that a major factor limiting the shad …


A Report On Black-Tailed Prairie Dogs In Nebraska, Their Biology, Behavior, Ecology, Management, And Responses To A Visual Barrier Fence, Nancy S. Foster Dec 1990

A Report On Black-Tailed Prairie Dogs In Nebraska, Their Biology, Behavior, Ecology, Management, And Responses To A Visual Barrier Fence, Nancy S. Foster

School of Natural Resources: Dissertations, Theses, and Student Research

I examined the effects of a visual barrier fence, which had a see-through visibility of 600/0, on the foraging, vigilance, and aggressive behaviors of adult female black-tailed prairie dogs from June through August 1990 in central Nebraska. I also examined changes in their home ranges and use of an area in response to this fence. Prairie dogs prefer an open view of their surroundings. Therefore, I expected animals near a visual barrier to spend more time in vigilance and aggression, and less time foraging. Adult female prairie dogs exposed to the visual barrier devoted more time to foraging and less …


Description Of The Tadpoles Of Gastrophryne Pictiventris And Nelsonophryne Aterrima (Anura: Microhylidae), With A Review Of Morphological Variation In Free-Swimming Microhylid Larvae, Maureen A. Donnelly, Rafael O. De Sá, Craig Guyer Jun 1990

Description Of The Tadpoles Of Gastrophryne Pictiventris And Nelsonophryne Aterrima (Anura: Microhylidae), With A Review Of Morphological Variation In Free-Swimming Microhylid Larvae, Maureen A. Donnelly, Rafael O. De Sá, Craig Guyer

Biology Faculty Publications

The tadpoles of Gastrophryne pictiventris and Nelsonophryne aterrima are described based on material collected in Costa Rica and Panama, respectively. The tadpole of G. pictiventris resembles those of the other species of Gastrophryne. The tadpole of N. aterrima differs from other New World microhylid tadpoles in location of the vent tube (medial), the spiracular opening (ventral to the gut), and eyes (dorsolateral). The unique configuration of mouthparts in N. aterrima is described. Morphological variation in microhylid tadpoles is reviewed and six larval characters are analyzed cladistically for IO New World microhylid genera.


Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager May 1990

Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager

Publications (WR)

Procambarus clarkii are found in extremely low numbers throughout Lake Mead, AZ-NV. The crayfish are an important dietary component for game fish. Enhancement of the crayfish population would broaden the fishery forage base. Crayfish were stocked and monitored in a study cove on Saddle Island to determine if the Procambarus clarkii population could be enhanced. A trapping survey of the area after the following reproductive season yielded low numbers of crayfish. A comparison of pre-stocking and post-stocking catch per trap day (CPTD) values revealed no significant increase in the population. Procambarus clarkii growth is limited by environmental factors in Lake …


An Analysis Of External Features As Predictors Of Reproductive Status In Small Mammals, Kenneth Wayne Mccravy Apr 1990

An Analysis Of External Features As Predictors Of Reproductive Status In Small Mammals, Kenneth Wayne Mccravy

Biological Sciences Theses & Dissertations

Reproductive status in specimens of nine populations of seven species of small mammals was evaluated by examining the external reproductive features of nipple size, condition of the pubic symphysis, and vaginal condition and, in males, testis position. Usefulness of these external features in predicting true monthly breeding rates was evaluated by comparing predictions of breeding rates with true rates based on necropsy. Accuracy of predictions of reproductive status of individuals based on single external features and combinations of external features and body measurements was then analyzed at a finer level by comparing those predictions with results of necropsy of the …


The Development Of A Policy For The Management Of Dingo Populations In South Australia, R. J. Downward, J. E. Bromell Mar 1990

The Development Of A Policy For The Management Of Dingo Populations In South Australia, R. J. Downward, J. E. Bromell

Vertebrate Pest Conference Proceedings: 14th (1990)

Competing concerns between conservation and sheep-growing interests in South Australia over problems associated with the naturalized dog,Canis familiaris dingo, prompted the development of a policy for the management of this subspecies. The background to the development of this policy is outlined. The policy provides for a compromise between the need to protect the livestock industry while ensuring the continued survival of the dingo as a wildlife species.


Estuarine Studies : An Activities Text For Maine Schools, Education Division - Department Of Marine Resources Jan 1990

Estuarine Studies : An Activities Text For Maine Schools, Education Division - Department Of Marine Resources

Maine Collection

Estuarine Studies : An Activities Text for Maine Schools

Fisheries Education Unit #16 - Produced by The Education Division, Department of Marine Resources, State House Station 21, Augusta, Maine 04333-0021.

Revised 1990. Printed Under Appropriation No. 3140.3260.



Fisheries Research Report No. 87 - The Recreational Marron Fishery In Western Australia, Summarised Research Statistics, 1971-1987, N. M. Morrissy, C. J. Fellows Jan 1990

Fisheries Research Report No. 87 - The Recreational Marron Fishery In Western Australia, Summarised Research Statistics, 1971-1987, N. M. Morrissy, C. J. Fellows

Fisheries Research Reports

The freshwater crayfish Cherax tenuimanus, called marron, provides an important recreational fishery in the south-west of Western Australia. The annual fishing catch and fishing effort have been monitored by a log book research programme and an end-of season telephone survey since the 1971/72 season.

Following the 1986/87 fishing season, the fishery remained closed for two seasons (1987/88 and 1988/89) to permit stocks to recover from the effects of high total fishing effort and unfavourable water conditions over the preceding seasons

This paper provides a detailed account of the catch and effort statistics to the close of the 1986/87 fishing season, …


Fisheries Research Report No. 84 - The Marine Open Shelf Environment: Review Of Human Influences, D. A. Hancock Jan 1990

Fisheries Research Report No. 84 - The Marine Open Shelf Environment: Review Of Human Influences, D. A. Hancock

Fisheries Research Reports

For the purpose of this review, the marine environment has been classified into three physical zones - the littoral zone, the open-shelf environment and the coral reef. Since the boundaries are arbitrary, there will inevitably be some overlap, but for this review the subject matter will be related to the area between low water of ordinary spring tides and the edge of the continental shelf; i.e., to a depth varying to 200 metres.

Human influences may have a dual role in affecting the marine environment, firstly in a causative manner and secondly in providing a remedy, in which case the …


Fisheries Research Report No. 92 - Spread Of The Introduced Yabbie Cherax Albidus Clark, 1936 In Western Australia, N. M. Morrissy, G. Cassells Jan 1990

Fisheries Research Report No. 92 - Spread Of The Introduced Yabbie Cherax Albidus Clark, 1936 In Western Australia, N. M. Morrissy, G. Cassells

Fisheries Research Reports

This report presents information on the probable original introduction of the eastern Australian yabbie to farm dams in the Wheat-belt Region of the southwest of Western Australia (in 1932 at Narembeen); the probable type of yabbie (the "White Yabby", Cherax albidus Clark 1936 ) and source (Miram Swamp in the Victorian Wimmera); and, in 1985, the first voicing of concern over the spread of yabbies to natural habitats, particularly in the higher rainfall region of the southwest, together with current national and international concerns and advice on introduced aquatic species.

Commercial harvesting ("extensive" aquaculture) of existing yabbie stocks in wheat-belt …


A Plan For Industrial Park Creation, Lake Dredging, And Wetland Restoration At Winona, Minnesota, Cal R. Fremling, Robert J. Bollant, Neal D. Mundahl Jan 1990

A Plan For Industrial Park Creation, Lake Dredging, And Wetland Restoration At Winona, Minnesota, Cal R. Fremling, Robert J. Bollant, Neal D. Mundahl

Cal Fremling Papers

From executive summary: "This document provides information pertinent to: 1) creating an industrial park within Winona's flood dikes by filling a drained wetland with dredged sand from Lake Winona, 2) deepening the east basin of Lake Winona by dredging, thus improving the shallow eutrophic lake and providing the necessary fill for the industrial park, and 3) mitigating the loss of wetland within the industrial park by restoring degraded wetlands adjacent to Lake Winona."


Pflanzengesellchaften Der Mongolei, Werner Hilbig Jan 1990

Pflanzengesellchaften Der Mongolei, Werner Hilbig

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

First paragraphs of the introduction:

In Fortführung der Forschungsreisen der russischen Floristen und Pflanzengeouraphen im vorigen und Anfang dieses Jahrhunderts wurden erste Expeditionen zur systematischen Erforschung der Naturressourcen der Mongolei in den 20er und 30er Jahren durchgeführt. Sie wurden von der Akademie der Wissenschaften der UdSSR und der Akademie der Wissenschaften der MVR (vorher Wissenschaftliches Komitee der MVR) organisiert. Auch die von der Geographischen GeselIschaft und der Akademie der Wissenschaften der UdSSR durchgeführten Expeditionen zur Erforschung der natürlichen Bedingungen und der Landwirtschaft in der Mongolei schufen Möglichkeiten zur Entwicklung der geobotanischen Forschungsrichtung (vgl. GUBANOV u. HILBIG 1989).

Als erste eigenständi"e …


Copper Accumulation By Gizzard Shad (Dorosoma Cepedianum) In The Charleston Side Channel Reservoir, Mark T. Christ Jan 1990

Copper Accumulation By Gizzard Shad (Dorosoma Cepedianum) In The Charleston Side Channel Reservoir, Mark T. Christ

Masters Theses

Exposure to trace heavy metals is being extensively studied in relation to their adverse and toxic effects on organisms. Processes affecting compartmentalization, biogeochemical cycling, and transport of trace metals in ecological systems must be elucidated if the impact of trace metal releases on biota are to be understood. Because elemental cycles are often closely linked to hydrologic processes, freshwater and marine systems serve as both vectors and sinks for trace metals in the environment. The regular addition of a heavy metal into an aquatic ecosystem will undoubtedly increase its persistance for availability to the existing biota. Once in the environment, …


Effects Of Ambient Lake Mohave Temperatures On Development, Oxygen Consumption, And Hatching Success Of The Razorback Sucker, Michael A. Bozek, Larry J. Paulson, Gene R. Wilde Jan 1990

Effects Of Ambient Lake Mohave Temperatures On Development, Oxygen Consumption, And Hatching Success Of The Razorback Sucker, Michael A. Bozek, Larry J. Paulson, Gene R. Wilde

Publications (WR)

Spawning of razorback suckers, Xyrauchen texanus, in Lake Mohave occurred from 10-22° C and larvae were collected at water temperatures from 10-15° C in 1982 and 1983. In the laboratory, hatching success was similar from 12-20° C, but reduced hatching success was found at 10° C while none hatched at 8°C. Development rate and oxygen consumption were positively related to incubation temperature. Direct effects of ambient Lake Mohave water temperatures on hatching success of razorback sucker embryos are considered minimal. Historical spawning temperatures for the species are hypothesized based upon successful incubation temperatures and comparison to the white sucker, …


Helminth Parasitism In Martens (Martes Americana) And Ermines (Mustela Erminea) From Washington, With Comments On The Distribution Of Trichinella Spiralis, Eric P. Hoberg, Keith B. Aubry, J. David Brittell Jan 1990

Helminth Parasitism In Martens (Martes Americana) And Ermines (Mustela Erminea) From Washington, With Comments On The Distribution Of Trichinella Spiralis, Eric P. Hoberg, Keith B. Aubry, J. David Brittell

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Helminths are reported for the first time from ermines (Mustela erminea) and martens (Martes americana) in Washington, USA. Among 22 adult ermines, 41% were infected by one or more of five species (Taenia mustelae, Alaria mustelae, Molineus patens, M. mustelae, and Trichinella spiralis). Among 78 adult martens from three geographic localities, the prevalence was 83%. Nine species were identified (Mesocestoides sp., T. mustelae and T. martis americana, Euryhelmis squamula, M. patens, Baylisascaris devosi, Physaloptera sp., Soboliphyme baturini, and T. spiralis). Trichinella spiralis …


Hawks, Eagles, And Falcons Of North America: Biology And Natural History, Paul A. Johnsgard Jan 1990

Hawks, Eagles, And Falcons Of North America: Biology And Natural History, Paul A. Johnsgard

Paul Johnsgard Collection

I have tried to present an adequate if far from exhaustive survey of the general biology, ecology, and behavior of all the included species, written so as to be understandable to the interested layman as well as useful to the biologist who might be looking for relevant literature citations or trying to deal with a specific question without resorting to extensive library searches. The larger number of species of North American hawklike birds (31, compared to 19 owl species) has required that I keep the individual species accounts substantially shorter. I have excluded the New World vultures from consideration, primarily …


Temporal And Spatial Patterns Of Abundance Of Age 0 Threadfin Shad (Dorosoma Petenense) In Overton Arm, Lake Mead, William Lee Pelle Jun 1989

Temporal And Spatial Patterns Of Abundance Of Age 0 Threadfin Shad (Dorosoma Petenense) In Overton Arm, Lake Mead, William Lee Pelle

Publications (WR)

Temporal and spatial patterns of age 0 threadfin shad (Dorosoma petenense) abundance and growth, in the Overton Arm of Lake Mead, were examined to evaluate the effects of resource availability on the young fish. This was part of a larger, game fishery enhancement study (Lake Mead Fertilization Project), designed to assess feasability of increasing survivorship of larval/juvenile shad by boosting phosphate levels, thereby increasing algal and zooplankton biomass, during the shad spawning period. Shad are the primary forage base for the striped bass (Morone saxatilis) and black bass (Macropterus salmoides) fisheries. Weekly samples were …


Wolf Population Survival In An Area Of High Road Density, L. David Mech Apr 1989

Wolf Population Survival In An Area Of High Road Density, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Wolf mortality in a high-road-density area of Minnesota exceeds that in an adjacent wilderness, and is primarily human-caused. The wolf population there is maintained primarily by ingress from the adjacent wilderness areas. A road density of 0.58 km/km2 can be exceeded and the area still support wolves if it is adjacent to extensive roadless areas.


Red Swamp Crayfish Ecology In Lake Mead, Suzanne E. Leavitt, Jennifer Stephens Haley, Mikell Hager, Donald H. Baepler, Nevada Department Of Wildlife Mar 1989

Red Swamp Crayfish Ecology In Lake Mead, Suzanne E. Leavitt, Jennifer Stephens Haley, Mikell Hager, Donald H. Baepler, Nevada Department Of Wildlife

Publications (WR)

Red swamp crayfish (Procambarus clarkii) were trapped in Flamingo Wash, an urban wash of Las Vegas, during four periods of 1988. Life history and reproductive success were determined. The trapped crayfish were marked and released into a study cove in Lake Mead as part of an experimental stocking program. Retrap data from the study cove were used to determine life history, habitat preferences, and movement patterns of the stocked crayfish. In addition, a literature search was done on red swamp crayfish ecology, including food preferences, life history, habitat preferences and fish predation.


Temporal And Spatial Variation In Pelagic Fish Abundance In Lake Mead Determined From Echograms, Gene R. Wilde, Larry J. Paulson Jan 1989

Temporal And Spatial Variation In Pelagic Fish Abundance In Lake Mead Determined From Echograms, Gene R. Wilde, Larry J. Paulson

Publications (WR)

Echograms have been used extensively to locate and estimate the relative abundance of marine fish stocks (Cushing 1973). In freshwater, echograms have been used to describe vertical (Netsch et al. 1971; Eggers 1978; O'Brien et al. 1984; Matthews et al. 1985), spatial (O'Brien et al. 1984; Wanjala et al. 1986) and temporal (Baker and Paulson 1983) patterns in fish abundance. Although most uses of echograms have been qualitative, Mullan and Applegate (1969) and Matthews et al. (1985) obtained relative estimates of fish abundance by counting targets (fish) on echograms. However, neither Mullan and Applegate (1969) nor Matthews et al. (1985) …


Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation Jun 1988

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines. Because …


Age And Growth Of The Tautog, Tautoga Onitis (Pisces: Labridae), From Lower Chesapeake Bay And Coastal Waters Of Virginia, E. Brian Hostetter Apr 1988

Age And Growth Of The Tautog, Tautoga Onitis (Pisces: Labridae), From Lower Chesapeake Bay And Coastal Waters Of Virginia, E. Brian Hostetter

Biological Sciences Theses & Dissertations

The tautog, Tautoga onitis (Pisces: Labridae), is rapidly gaining popularity in Virginia by anglers, spearfishermen and specialized commercial interests. In Virginia, tautog are seasonally abundant on hard bottom substrates in nearshore (ca. 2-10 m) habitats and inhabit offshore wrecks and reef areas (ca. 10-30 m) year round. Habitat restriction and slow growth of the species coupled with recent technological advances in marine electronics which simplify locating tautog populations by user groups may contribute to overexploitation of tautog within the region.

Tautog were collected over a two year period from the lower Chesapeake Bay and nearshore waters of the Atlantic Ocean …


Fish Aid: The Lake Mead Fertilization Project, Richard Axler, Larry Paulson, Peter Vaux, Patrick Sollberger, Donald H. Baepler Jan 1988

Fish Aid: The Lake Mead Fertilization Project, Richard Axler, Larry Paulson, Peter Vaux, Patrick Sollberger, Donald H. Baepler

Publications (WR)

Sport fishing at Lake Mead in Nevada and Arizona is a resource valued at nearly $100 million per year to southern Nevada. During the past two decades, salmonids, mostly trout, have disappeared entirely, the largemouth bass catch has drastically declined despite greater fishing pressure, and the condition factors for striped bass have steadily deteriorated. It appears that a major reduction in phosphorus loading caused by the upstream impoundment of the Colorado River to form Lake Powell in 1963 and advanced wastewater treatment removal of phosphorus from domestic wastewater inflows in 1981 are the principal factors responsible for decreased production at …


Wolf Distribution And Road Density In Minnesota, L. David Mech, Steven H. Fritts, Glenn L. Radde, William J. Paul Jan 1988

Wolf Distribution And Road Density In Minnesota, L. David Mech, Steven H. Fritts, Glenn L. Radde, William J. Paul

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Distribution of the wolf (Canis lupus) in parts of Wisconsin (Thiel 1985) and Michigan and Ontario (Jensen et al. 1986) has been related to the density of roads passable by 2-wheel-drive vehicles. Wolves in those regions generally do not occur where road densities exceed 0.58 km/km2, whereas similar areas nearby with fewer roads do contain wolves.

In a small segment of the wolf range in Minnesota, wolves did not have territories where roads exceeded a density of 0.73 km/km2 (T. K. Fuller, Minnesota Department of Natural Resources, unpublished data). In another small area of Minnesota …


Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation Nov 1987

Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation

Publications (WR)

Studies conducted by the University of Nevada-Las Vegas (UNLV), the Nevada Department of Wildlife (NDOW), the Arizona Game and Fish Department (AGFD), The Nevada Division of Environmental Protection (NDEP), and the United States Bureau of Reclamation (USBR) have identified decreased algal production as a major factor involved in the decline of the Lake Mead sport fishery. Phosphorus-laden silt particles in the Colorado River have been sedimenting out in Lake Powell since the completion of Glen Canyon Dam 286 miles upstream in 1963. This sharp decrease in phosphorus loading to Lake Mead (>5000 tons per year) has resulted in decreased …


Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel Oct 1987

Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel

Publications (WR)

Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and fiannehnouth sucker), the final preferendum is a less precise indicator of probable distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a …


Benthic Invertebrates And Crayfish Of Lake Mead, Susan K. Peck, William L. Pratt, James E. Pollard, Larry J. Paulson, Donald H. Baepler Sep 1987

Benthic Invertebrates And Crayfish Of Lake Mead, Susan K. Peck, William L. Pratt, James E. Pollard, Larry J. Paulson, Donald H. Baepler

Publications (WR)

The objectives of this study were to:

1. Establish baseline densities of benthic invertebrates and relative abundance of crayfish in Lake Mead.

2. Evaluate the distributions of benthic organisms and crayfish in relation to existing habitat conditions and 1imnological characteristics of Lake Mead.

3. Measure seasonal changes in abundances of benthic organisms and crayfish in Lake Mead.

4. Compare observations of Procambarus clarkii life history in Lake Mead to reports from other aquatic systems.

5. Evaluate the importance of benthic organisms and crayfish as food sources for game fish in Lake Mead.


Karyotypic Analysis Of Five Rodents And A Marsupial From Belize, Central America, David W. Burton, John W. Bickham, Hugh H. Genoways, Timothy J. Mccarthy May 1987

Karyotypic Analysis Of Five Rodents And A Marsupial From Belize, Central America, David W. Burton, John W. Bickham, Hugh H. Genoways, Timothy J. Mccarthy

University of Nebraska State Museum: Mammalogy Papers

Karyotypes and chromosomal banding patterns of six species of small mammals from Belize are presented and discussed in light of relevant data in the literature. Individuals of Heteromys desmarestianus had FN values of 72, which differs from previous reports. G-bands were obtained and compared to fluorescent bands (DAPI) and with the location of NOR sites. The karyotypes of Peromyscus mexicanus, Sigmodon hispidus, Oryzomys couesi, and Ototylomys phyllotis are identical to the karyotypes for these species described in the literature. Active NORs were located on four pairs of chromosomes in O. phyllotis and fluorescent bands obtained with the …