Animal Sciences Commons^™

The Status Of The Freshwater Shark Of Lake Nicaragua, Thomas B. Thorson, Donald E. Watson, C. Michael Cowan

Investigations of the Ichthyofauna of Nicaraguan Lakes

Nineteen sharks collected from freshwater at several points on Lake Nicaragua and the Rio San Juan were all of the same species and indistinguishable from marine Carcharhinus leucas of the Atlantic. Minor differences previously thought to separate C. leucas from the lake shark proved to be invalid. Females had slightly longer gill slits, somewhat greater breadth of pelvic fin, and a longer abdominal region than males. Clasper length indicated that the onset of sexual maturity in males occurs when they are between 1,600 and 1,700 mm in total length.
The classical theory or origin of the sharks from Pacific ancestry …

An Investigation Of The Feeding Habits Of The Bull Shark, Carcharhinus Leucas, In The Lake Nicaragua-Rio San Juan System, Robert E. Tuma

Investigations of the Ichthyofauna of Nicaraguan Lakes

The bull shark or cub shark, Carcharhinus leucas, occurs in tropical and subtropical waters of the Atlantic, Pacific, and Indian oceans. In the western Atlantic it occurs from New York to southern Brazil.

Partitioning Of Body Fluids In The Lake Nicaragua Shark And Three Marine Sharks, Thomas B. Thorson

Investigations of the Ichthyofauna of Nicaraguan Lakes

The relative volumes of major body fluids of freshwater and marine sharks are remarkably similar in spite of the differences in external medium and in osmotic pressure of body fluids. The small differences detected are in agreement with differences reported in comparisons of freshwater and marine te1eosts: a slightly higher total water content and a smaller ratio of extracellular to intracellular fluids in freshwater forms.

Serum Protein Variation In The Bull Shark, Carcharhinus Leucas Müller And Henle, 1841, C. Michael Cowan

Investigations of the Ichthyofauna of Nicaraguan Lakes

I. A detailed electrophoretic study was made of different developmental stages of the bull shark, Carcharhinus leucas Mülller and Henle, 1841.
2. Both qualitative and quantitative variations were found to exist between newborn and adult bull sharks.
3. Variations in the globulin portion may be related to the development of immunoglobulins.

Comparison Of Some Parameters Of Serum And Uterine Fluid Of Pregnant, Viviparous Sharks (Carcharhinus Leucas) And Serum Of Their Near-Term Young, Thomas B. Thorson, Jeffrey W. Gerst

Investigations of the Ichthyofauna of Nicaraguan Lakes

I. In eight females, serum urea concentrations of 134-336 mM/l. were interpreted as indications of previous environmental salinities.
2. Fetal serum solute concentrations usually resembled those of the mother, but in two cases where fetal urea was higher, it was interpreted as a lag in urea reduction following movement from salt to fresh water.
3. Uterine fluid was similar to maternal serum in all parameters except for its very low protein content.
4. No flushing of the uteri with environmental water occurs.
5. Independent osmoregulation apparently does not occur before birth, although required mechanisms may be present.
6. The full …

The Rectal Gland In Relation To The Osmoregulatory Mechanisms Of Marine And Freshwater Elasmobranchs, Giuseppe Gerzeli, Gian Franco De Stefano, Lorenzo Bolognani, Kurt W. Koenig, Maria Victoria Gervaso, Maria Fausta Omodeo-Salé

Investigations of the Ichthyofauna of Nicaraguan Lakes

The rectal gland of elasmobranchs secretes large quantities of electrolytes and is of primary importance in the osmoregulatory mechanisms of these animals (Burger and Hess, 1960; Burger, 1962). Analogously, various organs of other vertebrates are also known to be involved in salt secretion (Schmidt-Nielsen, 1965; Bonting, 1970; Bentley, 1971). In general, active ion transport is the basis of this phenomenon; in any case, it requires the presence of structural devices, morphologically and chemically well defined, and of metabolic capabilities which, taken singly, are not specific, but collectively are consistent with active ion transport and salt secretion.

Sexual Dimorphism In Number Of Rostral Teeth Of The Sawfish, Pristis Perotteti Miiller And Henle, 1841, Thomas B. Thorson

Investigations of the Ichthyofauna of Nicaraguan Lakes

Rostral tooth counts were made of 211 sawfish (Pristis perotteti) from the Lake Nicaragua-Rio San Juan System. The number of teeth is established early in development and it changes only on accidental loss of teeth, which are not replaced. The average number on the left side is equal to that on the right, but in individuals, either side may have as many as three more teeth than the other. Female tooth counts average 15.94 per side and range from 14 to 18, while males average 18.00 with a range of 16 to 20. Within litters, this dimorphism is …

Index Of Scientific Names

Investigations of the Ichthyofauna of Nicaraguan Lakes

Index of scientific names in Investigations of the Ichthyofauna of Nicaraguan Lakes.

Chromosomal Banding Patterns Of The Holarctic Rodents, Clethrionomys Rutilus And Microtus Oeconomus, C. F. Nadler, V. R. Rausch, E. A. Lyapunova, N. N. Vorontsov, R. S. Hoffman

University of Nebraska State Museum: Mammalogy Papers

Biologists have long been aware of close similarities between the mammalian faunas of northern Eurasia and northern North America (Flerov 1967; Rausch 1953, 1963; Sushkin 1925; Tugarinov 1934). This similarity is particularly strong between species of tundra and taiga ecosystems (Hoffmann and Taber 1967; Hoffmann 1974). Among the species having Holarctic distributions, the boreal red-backed vole, Clethrionomys rutilus (Pallas), and the tundra vole, Microtus oeconomus (Pallas) (Rausch, op. cit.), of the subfamily Arvicolinae (= Microtinae) (Kretzoi 1962; Repenning 1968), have wide distributions in Eurasia where they inhabit, but are not restricted to, tundra (Ognev 1950; Corbet 1966). East of the …

Bobwhite Quail Food Habits In The Southeastern United States With A Seed Key To Important Foods, J. Larry Landers, A. Sydney Johnson

Galliformes Specialist Group and Affiliated Societies: Reports and Other Materials

A search of the literature revealed 27 studies of food habits of bobwhite quail in the southeastern United States. These include data from nearly 20 ,000 birds. In this publication all seed foods reported in these studies are listed and evaluated, and a key to important species is included. Over 650 seed foods are listed, and volume and frequency classes are given for each seed food as reported in each study. Only 78 foods comprised 1 percent or more of the food volume in one or more studies. The 45 most important foods are ranked for each physiographic province. The …

Whole Issue Nebraska Bird Review (December 1975) 43(4)

Nebraska Bird Review

Table of Contents

Spring Waterfowl Migration in Lancaster County - 1970.................. 70

Merlin Nest in Nebraska ..................78

A Groove-billed Ani Seen Again in Nebraska.................. 79

A Brown Creeper's Nest in Nebraska.................. 80

First Pleistocene Record of the Golden Eagle from the Central Great Plains.................. 84

Notes.................. 84

Index of Volume XXX XIII ..................85

Sciurus Richmondi, J. Knox Jones Jr., Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Sciurus richmondi Nelson, 1898
Richmond's Squirrel

Sciurus richmondi Nelson, 1898:146. Type locality Escondido River, 50 mi. above Bluefields, Nicaragua (Nelson, 1899:100).

Context and Content
Order Rodentia, Family Sciuridae. The genus Sciurus is widely distributed in both the Old and New worlds. S. richmondi is a monotypic species closely related to S. granatensis; both species are members of the subgenus Guerlinguetus.

Dipodomys Phillipsii, J. Knox Jones Jr.

University of Nebraska State Museum: Mammalogy Papers

Dipodomys phillipsii Gray, 1841
Southern Banner-tailed Kangaroo Rat

Dipodomys phillipsii Gray, 1841:522. Type locality "near Real del Monte," Hidalgo.
Dipodomys ornutus Merriam, 1894:110. Type locality Berriozi-bal, Zacatecas.
Dipodomys perotensis Merriam, 1894:111. Type locality Perote, Veracruz.

Sturnira Thomasi, J. Knox Jones Jr., Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Sturnira thomasi de la Torre and Schwartz, 1966
Guadeloupe Yellow-shouldered Bat

Sturnira thomasi de la Torre and Schwartz, 1%6:299. Type locality Sofaia, 1,200 ft., island of Guadeloupe, Lesser Antilles.

Context and Content: Order Chiroptera, Family Phyllostomatidae, Subfamily Stenoderminae. The genus Sturnira contains about 10 species and is confined to the tropical and subtropical regions of the New World. Sturnira thomasi is a monotypic species.

Additional Records Of The Stenodermine Bat, Sturnina Thomasi, From The Lesser Antillean Island Of Guadeloupe, Hugh H. Genoways, J. Knox Jones

University of Nebraska State Museum: Mammalogy Papers

Sturnira thomusi was named and described by de la Torre and Schwartz (Proceedings of the Biological Society of Washington 79: 297-303, 1966) on the basis of a single male from the island of Guadeloupe, Lesser Antilles, that was captured by Richard Thomas in 1963. The holotype of S. thomasi has until now been the only known specimen of this unique species. In late July of 1974, a field party from the Museum of Texas Tech University (supported by a grant from the National Science Foundation, GB-41105) collected bats on Guadeloupe and took four additional individuals of S. thomasi, all …

Whole Issue Nebraska Bird Review (September 1975) 43(3)

Nebraska Bird Review

TABLE OF CONTENTS

1975 (Fiftieth) Spring Migration and Occurrence Report ... 46

Young Mountain Plover Seen in Kimball County ... 54

Notes ... 57

A Sutton's Warbler? ... 62

Scott's Oriole Reported ... 64

1975 Fall Field Day ... 66

A Junco Is a Junco Is a Junco ... 67

Physical And Chemical Properties Of Outdoor Beef Cattle Feedlot Runoff, C. B. Gilbertson, J. R. Ellis, J. A. Nienaber, T. M. Mccalla, T. J. Klopfenstein

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Within the past decade, emphasis has been placed on the quality of our environment. Beef cattle feedlots have been singled out as a significant source of environmental pollution. Environmental protection provided by control facilities requires basic knowledge of the physical and chemical properties of feedlot runoff. This bulletin summarizes studies of physical and chemical properties of beef cattle feedlot runoff completed from August, 1968 through December, 1972.

Sire Comparisons For Holsteins In Mexico Versus The United States And Canada, R. E. Mcdowell, G. R. Wiggans, J. K. Camoens, L. Dale Van Vleck, D. G. St. Louis

Department of Animal Science: Faculty Publications

Henderson's mixed model procedure was used to determine sire comparisons for Holstein sires from the United States, Canada, or local bred in 48 Mexican herds. For sires with five or more daughters, 74% of the sires in artificial insemination from the United States had plus values compared to 34% from Canada, 44% from the local stud, and 40% for local bred sires. Genetic correlations with Mexican sire comparisons were Northeast Artificial Insemination Sire Comparison with >20 daughters in Mexico .86, with 10 to 20 daughters .71, United States Department of Agriculture (USDA) proof >10 daughters .81, and Canada Northeast Artificial …

Factors Affecting Performance Of Holsteins In Subtropical Regions Of Mexico, R. E. Mcdowell, J. K. Camoens, L. Dale Van Vleck, E. Christensen, E. Cabello Frias

Department of Animal Science: Faculty Publications

Effects of herd, year, age, season, and their interactions on milk yield, lactation length, and reproductive efficiency for purebred and high grade Holsteins were determined by analysis of variance of 17,255 lactation records from 48 herds in Mexico. Herds differed in all traits. Herd average milk yield ranged from 2620 to 7670 kg. Years, ages, and seasons were important to milk yield, but these variables had little influence on lactation length, days open, days dry, and calving interval. Most two-, three-, and four-way interactions for milk yield and days in milk were of importance. Main effects and interactions accounted for …

A New Species Of Eptesicus From Guadeloupe, Lesser Antilles (Chiroptera: Vespertilionidae), Hugh H. Genoways, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

In the course of field studies on bats of the Antillean region, three specimens of the genus Eptesicus were obtained on the island of Guadeloupe in the Lesser Antilles. The nearest known populations of this genus are on Puerto Rico 500 kilometers to the west (E. fuscus wetmorei), on the northern coast of South America 850 kilometers to the southwest (E. fuscus miradorensis), and on Tobago 550 kilometers to the south (E. brasiliensis melanopterus). Study of the specimens from Guadeloupe reveals that they represent a distinct species that is most closely related to Eptesicus …

Genetic Value Of Sexed Semen To Produce Dairy Heifers, L. Dale Van Vleck, R. W. Everett

Department of Animal Science: Faculty Publications

Economic value of sexed semen due to increased intensity of selection on cows to produce replacements can be determined from a slight modification of a procedure used to predict net worth of semen of different costs from sires of different transmitting abilities. Table values corresponding to precision of sexing (selection intensity allowed for cows), discount rate, investment period, and conception rate are used in simple equations to determine the economic value of sexed or regular semen. The additional price that can be paid for sexed semen as compared to regular semen also can be determined. For example, sexed semen resulting …

Sodium Bentonite In Ruminant Rations, Daniel P. Colling

Open Access Master's Theses (through 2010)

Sodium bentonite, an expanding clay, is being used in many different ways in industry today.The livestock and feed industry, for example, use it in many different ways.It is used as a pellet binder to maintain a fat test in dairy animals, as a digestive aid in the poultry industry and as a “buffering agent” in feedlot rations.

A two-pronged investigation was undertaken to determine the effect sodium bentonite could have on the ruminant feeding industry.One part of the investigation sought to determine if bentonite could partially or entirely alleviate subclinical lactic acidosis with problem rations.The other part of the investigation …

Vegetation Development In Relation To Age Of River Stabilization Structures Along A Channelized Segment Of The Missouri River, John Arthur Vaubel

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

During the summer of 1974, I sampled sites of vegetation representative of successional trends in plant communities along the Missouri River floodplain from Sioux City, Iowa, to Rulo, Nebraska. Five district community types listed from youngest to oldest are as follows: Salix spp. – dominated, Populus deltoides – dominated, Platanus occidentalis-Ulmus rubra – dominated, Tilia americana-Quercus rubra – dominated, and Quercus macrocarpa-Carya ovata – dominated vegetation.

The technique of relating vegetation succession to age of river stabilization structures was found to be useful and offered a quite precise method of developing a timescale …

Whole Issue Nebraska Bird Review (June 1975) 43(2)

Nebraska Bird Review

Table of Contents

The Seventy-fourth Annual Meeting ........................................ 22

Blue-Gray Gnatcatcher Breeding in Lancaster County .................................... 23

1974 (Seventeenth) Fall Occurrence Report .................................................... 24

Some Waterfowl Breeding Records for Lancaster County ............................. 40

Anhinga Seen in Nebraska Again ........................................... 41

A Monk Parakeet in the Kearney Area ...................................... 42

Book Reviews ........................................................ 42

Notes .................................................43

Reproductive Efficiency Of Jerseys, Red Sindhis, And Crossbreds, R. E. Mcdowell, B. F. Hollow, J. K. Camoens, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Ten measures related to breeding efficiency were used for comparisons among pure Jerseys and Red Sindhis and crossbreds with ¾, ½, or ¼ European dairy inheritance (Brown Swiss, Holstein, or Jersey) at two locations. Jerseys and crossbreds were common to both herds with Sindhis only at Jeanerette. Means for age at puberty (first estrus after 12 mo) were 425 ± 4.2, 434 ± 6.9, 459 ± 6.9, 504 ± 14.1, and 717 ± 40.4 days for Jerseys, crosses of ¾, ½, or ¼ and Sindhi. The increase in age of puberty was additive but not entirely. The ¾and ½ tended …

Collections Of Recent Mammals In North America, Jerry R. Choate, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Mammalogy is the only systematic discipline that has previously undertaken periodic (that is, more than one) surveys of its holdings in North American collections. The first such survey (reported on by Howell, 1923) pertained to mammals in collections as of April of 1922. The report of the second survey (Doutt et al., 1945) summarized collections of mammals in North America as of 1943. The report of the third survey (Anderson et al., 1963) pertained to specimens of mammals in North American collections as of 1962. At that time, it was assumed that to prepare an updated report on North American …

A New Subspecies Of Geomys Bursarius (Mammalia: Geomyidae) From Texas And New Mexico, Robert J. Baker, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

As part of a study of the systematics and ecology of pocket gophers occurring on the high plains of Texas and eastern New Mexico, numerous populations of the plains pocket gopher, Geomys bursarius, were examined karyotypically. Four chromosomal races were described from this area by Baker et al. (1973). Additional studies lead us to believe that two of these races represent an undescribed subspecies of the plains pocket gopher. In addition to karyological evidence, specimens of this subspecies are morphologically distinct from those of all contiguous populations of Geomys bursarius major, the race to which they previously were assigned. …

Mammals Of The Guadalupe Mountains National Park, Texas, Hugh H. Genoways, Robert J. Baker, John E. Cornely

University of Nebraska State Museum: Mammalogy Papers

Our survey began in late May 1973 and continued through August 1975. The objectives of our study, which was supported by the National Park Service, were to survey the mammals occurring in the Guadalupe Mountains National Park, Texas, and to correlate their distribution with major plant associations. This inventory of the natural resources of the park is preliminary to the development of any serious management program. Therefore, we present the following accounts to serve as baseline data for future mammalian work in the park and development of the master plan for the park.

Editors' Note To Biological Investigations In The Guadalupe Mountains National Park, Texas., Hugh H. Genoways, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

The Guadalupe Mountains National Park, which is located in TransPecos Texas between Carlsbad, New Mexico, and EI Paso, Texas, is one of the newest national parks being formed by the Congress in 1967. The Guadalupe Mountains and the associated Chihuahuan Desert included in the park represent a unique biological area in which a fragile biological equilibrium exists between the fauna and flora of the Chihuahuan Desert of the lowlands and the Rocky Mountains of the high elevations. The preservation of this area will depend upon sound management decisions. This volume is the result of a symposium held at The Museum …

Research In National Parks, Robert J. Baker, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

This was our first involvement with research in the National Parks and we would like to make some observations concerning interactions among basic researchers, park personnel, and the philosophy on which our park systems are based. Our conclusions are not based only on our own experiences, but also on conversations with other basic researchers (especially those who contributed to this symposium) and with park personnel who have aided and worked with other researchers who were not employed by the National Park Service.