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Geographic Distribution Of The San Juan Ichthyofauna Of Central America With Remarks On Its Origin And Ecology, William A. Bussing

Investigations of the Ichthyofauna of Nicaraguan Lakes

The scientific study of fishes of the Great Lakes of Nicaragua began in 1864 with the description by Gunther of Heros labiatus (=Cichlasoma labiatum) from Lake Managua. Subsequently, Gunther reported on several other species collected in the Great Lakes by Captain J. M. Dow. Astorqui (1967) reviewed the sparse ichthyological literature dealing with Nicaraguan fishes and pointed out the paucity of recent studies. Since then Villa (1971) has produced a provisional list of the freshwater and brackish water fishes of Nicaragua and Astorqui (1972) has analyzed the ichthyofauna of the Great Lakes Basin. Riedel (1972) discussed the geological …

Some Speculations About "The Great Nicaraguan Lake", Jaime Villa

Investigations of the Ichthyofauna of Nicaraguan Lakes

The available evidence indicates that Lakes Managua and Nicaragua were broadly connected in the past, when most of the fish species invaded the "Great Nicaraguan Lake". Due to the lowering of the water level (caused perhaps by tectonic movements and/or erosion produced by the Rio San Juan), Lake Managua became separated from Lake Nicaragua in the Tipitapa area. Water movement from Lake Managua is achieved mostly by seepage through a porous dropoff which prevents the exchange of fishes between the lakes. At about the same time, if not earler, Lake Xilml also became separated. After the more or less permanent …

Lake Nicaragua Fishery Resources, William D. Davies

Investigations of the Ichthyofauna of Nicaraguan Lakes

Data collected during this survey indicated that the number of full-time fishermen has not increased appreciably over the past several years. However, it is likely that, if the demand for fish were to increase, a number of the present part-time fishermen would increase their effort to full-time. Indications are strong that the fish catch from this lake could at least be doubled by the existing population of fishermen, using the same gear, if market conditions were such as to encourage greater fishing effort.
The lake's overall fisheries resources are far from being exploited to their maximum, with the possible exception …

Ontogeny Of Parent-Contacting In Young Cichlasoma Citrinellum (Pisces, Cichlidae), David L. G. Noakes, George W. Barlow

Investigations of the Ichthyofauna of Nicaraguan Lakes

There is an extensive literature on cichlid fish behavior, but most of this treats the behavior of adults (see BREDER & ROSEN, I966, for example). Much of this is based on laboratory observations with little corroborative information from field studies. Recently there has been an increasing trend to study the development of behavior, in cichlids as in other animals. In part this results from the 'nature-nurture' controversy regarding factors control~ ling behavior (e.g. KRUIJT, I964). However, there is also interest in the study of young animals for their own sake (e.g. WARD & BARLOW, I967).
The present study was undertaken …

Competition Between Color Morphs Of The Midas Cichlid, Cichlasoma Citrinellum, In Lake Jiloá, Nicaragua, Kenneth R. Mckaye, George W. Barlow

Investigations of the Ichthyofauna of Nicaraguan Lakes

Color polymorphism, or polychromatism, is a recurring phenomenon throughout the animal kingdom. In fishes one form, the goldfish, is particularly notable because of its conspicuousness and its occurrence in nature in such a large number of widely unrelated species; yet it is seldom common in anyone species (Webber et al., 1973). The Midas cichlid, Cichlasoma citrinellum, is unusual in this respect because in many of the lakes where it occurs in Nicaragua brilliantly colored morphs are relatively common. These morphs lack the species-typical dark markings, and individuals vary smoothly from white through yellow, orange, red, and mixtures of …

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 …

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.

Blood And Tissue Identification Of Selected Birds And Mammals, Part Ii: Cross Reaction Patterns Of Birds And Mammals, Using Deer, Bovine, Raccoon, Chicken And Mallard Duck Antiserum, Part 1, David W. Oates, Debra L. Weigel

Other Publications in Wildlife Management

Most enforcement cases involving our laboratory deal with the identification of a blood stain or meat sample which is suspected to be deer. Determining whether it is, indeed, from deer is not difficult. But, if the sample is not deer, exact identification can prove to be a more time consuming and tedious process. To eliminate the need to obtain antiserum for each individual species and aid identification, we undertook an investigation on which species and the extent to which several species may cross react with antisera of some common birds and mammals, especially deer. Deer, cow, and raccoon were selected …

G76-312 What Are Good Labor Relations?, Robert E. Perry

University of Nebraska-Lincoln Extension: Historical Materials

Good labor relations is the factor most often identified as necessary for successful employment by farm employees. Farmers who employ hired labor also rate "good labor relations" as an important factor, though many rate good wages as more important

What are "good labor relations"? From answers received from employees, they appear to involve a mixture of human characteristics and open communications that build mutual respect and loyalty.

Luteinizing Hormone, Testosterone, Growth And Carcass Responses To Sexual Alteration In The Ram, B. D. Schanbacher, J. J. Ford

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A total of 130 ram lambs were used in a study to determine the effects of sex alteration on serum hormone levels, growth rate and carcass traits. Sex alteration included no treatment (intact rams), scrotal ablation to alter normal testicular secretion (short scrotum rams) and castration to completely remove influences derived from the testes (wethers). Although these data suggest that scrotal ablation at birth did not produce complete azoospermia in Finn-crossbred rams, reduction (P<.01) in testicular weight did produce significant results. Serum testosterone in short scrotum and intact rams was similar, whereas castration resulted in considerably lower concentrations of this steroid (P<.01). On the other hand, serum luteinizing hormone was increased (P<.01) threefold in short scrotum rams and 12-fold in wethers as compared to that of intact rams. Because these results cannot be fully explained by changes in serum testosterone, it is speculated that changes in secretory products of the testis which accompany degeneration of the germinal epithelium are responsible for elevated luteinizing hormone. Post-weaning average daily gain (P<.01) and feed efficiency were highest in intact and short scrotum rams indicating that testosterone (or testis) may be beneficial. Although dressing percentage and adjusted backfat were highest (P<.01) in wethers, carcass weight and yield grade were advantageous (P<.01) in short scrotum and intact rams. Quality grades were similar; all animals reached average choice.

The Effects Of Boating Upon Lead Concentrations In Fish, David Oates

Nebraska Game and Parks Commission: Staff Research Publications

The concentration of lead in fish muscle tissue from lakes where boating is heavy and where it is prohibited was measured. The lead levels ranged from less than 0.05 to 1.35 ppm but did not differ significantly between those in the controlled and non-controlled boating lakes. Lead levels apparently pose no public health hazard.

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 …

A Dinosaur Revival, Harvey L. Gunderson

University of Nebraska State Museum: Programs Information

Just about everyone loves dinosaurs! Just ask any museum guard, 4th grader, or grandparent looking for souvenirs at a museum's gift shop. The only natural history exhibits that persistently challenge their popularity, in a child's mind, are the fabled mummies of ancient Egypt. Why does just the mention of the name "dinosaur" activate the imagination of most people? Naturally their size and dominating appearance are significant; however, we would hope people are also ---I intrigued by the very fact that these majestic beasts really existed at all, and for some ill-explained reason ----I seemed to disappear at the height of …

Photoconductivity In Bone And Tendon, Robert G. Fuller, A. A. Marino, R. O. Becker

Robert G. Fuller Publications

Ultraviolet light can be used to stimulate electrical current flow in bone and tendon. This stimulated photocurrent is directional. In tendon the photocurrent parallel to the fibrils is greater than the photocurrent perpendicular to the fibrils. In bone, the longitudinal photocurrent is less than the transverse photocurrent.

Prospects For Control Of Phytopathogenic Bacteria By Bacteriophages And Bacteriocins, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The last review on bacteriophages and bacteriocins of phytopathogenic bacteria was that of Okabe & Goto (98). All but one (21) of the subsequent reviews (II, 12, 60, 94, 104) have dealt primarily with viruses and bacteriocins of bacteria other than phytopathogens. The most recent microbiological compendia that in­ clude bacteriophages and bacteriocins are of limited value for phytobacteriolo­ gists because the authors generally overlook or ignore such agents (29, 47, 77, 119). However, Adam's classic .book (4), the review by Bradley (II), and the bibliography of Raettig (102) are still of value to phytobacteriologists as are reviews dealing principally …

A Pollen Selection System For Alcohol-Dehydrogenase-Negative Mutants In Plants, Drew Schwartz, John Osterman

School of Biological Sciences: Faculty Publications

Exposure of freshly shed maize pollen to allyl alcohol vapors allows selective fertilization by mutant alcohol-dehydrogenase-negative grains. Wild-type pollen grains are killed by the enzymatic conversion of allyl alcohol to the highly toxic acrylaldehyde.

Anatomical Observations On Floating Leaves, Robert B. Kaul

School of Biological Sciences: Faculty Publications

An examination of 24 genera of aquatic plants having floating leaves and leaf-like thalli has been made. Functional stomata occur on the adaxial sides of floating leaves of angiosperms and some ferns, and in some floating leaves there are stomata on the abaxial surface as well. Most floating leaves have prominently chambered mesophyll, and in some instances the chambers are locally enlarged and form buoys.

Review Of The Oligocene Cetacea, Frank C. Whitmore Jr., Albert E. Sanders

United States Geological Survey: Staff Publications

Early in the Oligocene Epoch, Cetacea of the primitive suborder Archaeoceti had already declined sharply from their apparent abundance in Eocene seas. By the beginning of the Miocene, archaeocetes are known to have survived only in the northeast Atlantic and southwest Pacific Oceans. Concurrently with this decline, the first members of the suborders Odontoceti and Mysticeti appeared. They are known from only a few specimens, mostly in upper Oligocene deposits, on both coasts of North America, in Germany, Austria, Italy, the Caucasus, Azerbaijan, Australia, and New Zealand. Two important odontocete genera, Agorophius and Xenorophus, come from beds that are …

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 …

Morphological Variation In Natural Infections Of Oochoristica Bivitellobata Loewen, 1940 (Cestoidea: Anoplocephalidae), Daniel R. Brooks, Monte A. Mayes

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Three specimens of Cnemidophonls sexlineatus, the six-lined whip tail lizard, collected in the vicinity of Guide Rock and Arapahoe, Nebraska on June 20-21, 1974 were found to be infected with one, three, and fifteen specimens of Oochoristica bivitellobata Loewen, 1940. These worms exhibited variations in morphology not previously reported for the species. Worms were relaxed and killed in ice-water, fixed with AFA, stored in 70% ethanol, stained with Mayer's carmalum or Mayer's hematoxylin, and mounted in Canada balsam for study as whole mounts. Representative specimens have been deposited with the Harold W. Manter Laboratory, University of Nebraska State Museum. Measurements …

Fish Populations Of The Middle Loup River, Nebraska, Lawrence Burman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

From September 5,1970 to August 10,1971,27 species and 12,499 fish were collected from the Middle Loup River by seine. The red shiner, Notropis lutrensis, and the sand shiner, Notropis stramineus, composed 72 per cent of the total fish taken. The minnow family, Cyprinidae, composed 88 per cent of the total fish collected. Species diversity and number of species increased with the increase in the size of the river.

Introduction

Very little research has been done with fish distribution in the rivers of Nebraska. As time goes by, conditions change and so do the fish populations. Thus, it is …

New Records Of Native And Introduced Plants From Nebraska, Steven P. Churchill, Robert B. Kaul, David M. Sutherland

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Recent field work in Nebraska by staff of the University of Nebraska Herbarium has produced a number of records of previously uncollected specimens and has confirmed the presence of species collected only a few times long ago. Some of the records are of American species which are indigenous to Nebraska or which have recently spread to the state, while other records are of foreign species which are thoroughly established in the wild. Some of these are potentially serious weeds, though none have reached that stage yet.

All specimens cited are deposited in the University Herbarium in Nebraska Hall, Lincoln, except …

Limnetic Microcrustacea Of Some Flood Control Reservoirs In Southeastern Nebraska, G.R. Helzer, G.L. Hergenrader

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Limnetic microcrustacean communities of 5 flood control reservoirs in the Salt Valley Watershed of Southeastern Nebraska were studied from June 1968 to January 1970. The average community during summer was comprised of 3.2 c1adoceran and 2.4 copepod species. Cladoceran densities usually exceeded those of the copepods. Bosmina longirostris was found in the more productive reservoirs while Bosmina coregoni inhabited the light-limited, nonproductive reservoirs. Congeneneric occurrences of Diaptomus species were common in three of the five reservoirs. Congeneric Daphnia occurrences were found on 61 percent of the sampling dates, excluding one reservoir in which only one species of Daphnia was found. …

Transactions Of The Nebraska Academy Of Sciences- Introduction, John D. Lynch

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

CONTENTS

Nebraska Academy of Science, officers ........................ iii

Instructions to contributors ................................. iv

ANTHROPOLOGY

BIOLOGICAL AND MEDICAL SCIENCES

EARTH SCIENCES

UNCLASSIFIED

ESTABLISHMENT OF TRANSACTIONS

NEBRASKA ACADEMY OF SCIENCES, INC.

REPRINTS

EDITOR'S CORNER

Diversity As A Tool To The Paleoecologic Study Of A Pennsylvanian Shale, Stephen Emanuel Jacobs

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The fauna of the Stull Shale Member (Upper Pennsylvanian, Virgil Series) in southeastern Nebraska and southwestern Iowa is dominated by brachiopods. The biofacies succession is largely represented by a double recurrence of the Crurithyris (Neochonetes) Assemblages, interrupted by the Crurithyris-(Productoidea Assemblages in the Middle Stull and by the Crurithyris-Low Diversity-Low Biomass Assemblage in the Upper Stull.

The Shannon-Wiener information function and some abiotic parameters (Rock color and lime content) have been used to interpret the paleoenvironment represented by each of these assemblages. Moderate diversity index values are present in the Crurithyris -(Neochonetes) Assemblages for …

Functional Analysis: Some Recent Philosophical History, David W. Paulsen

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

1. Introduction. A standard treatment of functional analysis ("functionalism") among philosophers of science has recently come under attack by a new variety of "functionalist" in the philosophy of psychology.¹ Jerry Fodor, the chief proponent of this new approach, challenges the view that functional statements can be eliminated in favor of causal (nomological) statements. He supports his position by providing the outlines of a functional analysis of mental concepts which he believes illuminates the mind-body problem. In particular, Fodor holds that his version of functionalism clarifies how a materialist may avoid adherence to the reductionist thesis that mental concepts …

The Effect Of Dietary Administration Of Ethylenedlaminetetraacetic Acid Upon The Mineral Content Of Mouse Tissues, Gary Sprague

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A 3.4 mM ethylenediaminetetraacetic acid (EDT A) aqueous solution and 25 mM Na₂EDTA, Na₄EDTA and CaNa2EDTA aqueous solutions were fed laboratory white mice as drinking water for 28 day periods. EDT A in the blood plasma of animals used at the end of the 28 day period was undetectable using a colorimetric assay. Ca, Mg and Zn content of the bone, kidney, liver and muscle tissues were determined using atomic absorption spectrophotometry. Liver Ca and kidney Mg were reduced in animals administered CaNa₂EDTA; kindey Ca and Mg were elevated in animals administered Na_{2 …}

Relative Abundance And Habitat Preference Of Some Small Mammals In Southeastern Nebraska, Jerry A. Walker

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Several small mammal species collected from southern Lancaster and northeastern Saline Counties, Nebraska showed variations in relative abundance and habitat preference from that recorded in the literature. The masked shrew (Sorex dnereus) was found in riparian and upland communities. The western harvest mouse (Reithrodontomys megalotis) (60 per cent of all captures) was the most abundant species in the area. The meadow vole (Microtus pennsylvanicus) occurred in perennial grass upland areas, and the prairie vole (Microtus ochrogaster) was found in annual grass and forb habitats. One species of vole was found to seldom frequent the …

Direct Effects Of Wide-Area Malathion Application On Fish, Norman P. Stucky

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The primary objective of this investigation was to determine if fish mortality would result directly from a wide-area application of 561 fluid grams, technical grade malathion per hectare. This cooperative study with the Department of Entomology, University of Nebraska, was conducted in Dawson County, near Lexington, Nebraska. Field tests were conducted on two adjoining 9.94-square-kilometer areas. The area receiving spray served as the experimental area; the other area served as a control. Mortality rates were determined both for captive bluegill (Lepomis macrochirus) and for fish populations native to Buffalo Creek. Data obtained throughout the course of this study indicated …