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Length/Weight Frequencies For Five Species Of Fish In Lake Nicaragua, Richard J. Beatty, Kurt W. Koenig

Investigations of the Ichthyofauna of Nicaraguan Lakes

This paper places on record data on the length/weight frequencies of five commercially important species in Lake Nicaragua: Megalops atlanticus, Centropomus parallelus, Lepisosteus tropicus, Cichlasoma citrinellum and Cichlasoma nuaraguense.
The data were collected between November, 1971 and June, 1972, during a preliminary study of the fishery of Lake Nicaragua. The program was sponsored by the Instituto de Fomento Nacional (INFONAC) of Nicaragua, with financial and technical assistance provided by the United Nations Food and Agricultural Organization (FAO) and the United States Peace Corps.

La "Pepesca Gaspar", Otro Pez Desconocido Del Gran Lago, Jaime Villa

Investigations of the Ichthyofauna of Nicaraguan Lakes

En un articulo recientemente aparecido, informe sobre la presencia de un pez hasta entonces desconocido en el Lago de Nicaragua, el gimnoto cilindrico. Existen, sin embatgo, varias especies adicionales que he ido descubriendo poco a poco y que ire presentando de igual modo al publico lector.

The Red Devil-Midas-Arrow Cichlid Species Complex In Nicaragua, George W. Barlow, John W. Munsey

Investigations of the Ichthyofauna of Nicaraguan Lakes

Within this group (section Amphilophus) of Nicaraguan cichlid fishes, we recognize two of the eight named species, Cichlasoma labiatum (Günther) and C. citrinellum (Günther). A new species from Lake Apoyo, C. zaliosum Barlow, is described. The red devil cichlid (C. labiatum) occurs only in the Great Lakes, but the Midas cichlid (C. citrinellum) is found in most of the surrounding lakes as well, and also in Costa Rica; where the two species are sympatric they differ most from one another. In Lakes Masaya and Jiloá some individuals of C. citrinellum show features of C. labiatum …

Relative Abundance And Distribution Of The Mojarra (Cichlasoma Citrinellum) In Lake Nicaragua, Sergio Martínez C

Investigations of the Ichthyofauna of Nicaraguan Lakes

Sixteen families and at least forty-five species of fishes have been reported from Lake Nicaragua (Astorqui, 1971; Villa, 1971). The National Development Institute of Nicaragua (INFONAC) has investigated the potential fish resources and their distribution in the lake in order to implement a program of development and a rational management of the fisheries of the lake (INFONAC, 1974). The study at hand was conducted in connection with that investigation to define the abundance and natural habitat of the mojarra, Cichlasoma citrinellum. This fish belongs to the family Cichlidae, which is represented in the lake by several species.
Cichlasoma …

Systematic Status Of The Cichlid Fishes Cichlasoma Dorsatum, C. Granadense And C. Nigritum Meek, Jaime Villa

Investigations of the Ichthyofauna of Nicaraguan Lakes

In his Synopsis of the Fishes of the Great Lakes of Nicaragua, Meek (1907) described 3 new cichlid fishes, Cichlasoma dorsatum, C. granadense and C. nigritum. The descriptions appeared after the two major revisions of the genus Cichlasoma (Pellegrin, 1904; Regan, 1905), which perhaps explains why they have since been ignored.

Variación, Coloración Y Estado Sistemático Del Pez Centroamericano Cichlasoma Nicaraguense (Familia Cichlidae), Myrna I. López

Investigations of the Ichthyofauna of Nicaraguan Lakes

Cichlasoma balteatum and C. spilotum are placed in the synonymy of C. nicaraguense on the basis of a review of the literature and examination of fresh material from Lake Nicaragua and the Atlantic slope of Costa Rica. Observations on coloration and caudal fin scalation are included.

Cross-Fostering And Parent-Offspring Responses In Cichlasoma Citrinellum (Pisces, Cichlidae), David L. G. Noakes, George W. Barlow

Investigations of the Ichthyofauna of Nicaraguan Lakes

Previous studies of parent-young interactions in cichlid fish have established some of the details of such relations, but have raised, or left unanswered many questions. In particular, there are questions as to the recognition of parents and young by each other, and to what extent learning might be involved in such recognition.
Based on observations of exchanges of parents between families of Cichlasoma citrinellum, we suggest that parents learn to recognize young during each parental cycle. They appear to have a moderately short term memory for recognition of young, and accept young corresponding to this memory.
Parental fish accept …

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 …

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.

Laboratory Apparatus For Providing Diel Temperature Regimes For Aquatic Animals, Wayne A. Wurtsbaugh, G. Davis

Watershed Sciences Faculty Publications

In studies of the effects of elevated temperature on aquatic organisms, little emphasis has been placed on modeling the fluctuating temperatures to which organisms are exposed in nature. To some extent this may be related to problems of design and maintenance of apparatus for fluctuating temperature control. The complexity of apparatus used to provide cycled temperatures has ranged from manually controlled valves for introducing water of different temperatures into aquariums (Kelso 1972), to a complex and expensive feedback system, regulated by rotating cams, that controls the temperature of influent water (Honeywell Cam Programmer Thermometers, Fort Washington, Pennsylvania). To facilitate studies …

Bulletin 3984 - Meat Ducks In W.A., T. J. Purling

Bulletins - 3000 - 3999

While the duck industry in the Eastern States of Australia has used several breeds, Western Australia has until recently relied on the Muscovy. Most overseas countries with well developed meat duck industries have used the Muscovy only to a minor extent.

The Australian Pekin has been established in W.A. as an important meat breed since 1967/68, being suited to the production of large numbers of small carcass ducks throughout the year.

The Muscovy is still used for the large carcass trade, particularly at the Christmas and Easter seasons.

Strip Vs Continuous Grazing Of Irrigation Pasture, R Sprivulis, R. Bettenay, T. Pavy

Journal of the Department of Agriculture, Western Australia, Series 4

A report on trial work looking at the alternative grazing systems andthe returns generated.

Bulletin No 3966 - Vitamin A And Animal Health, J. Johnson

Bulletins - 3000 - 3999

Vitamin A is one of the essential vitamins for animal health. Grazing animals obtain their vitamin A requirements mostly from the carotene in green feed. This carotene is converted to Vitamin A in the intestinal wall and is passed to the liver and to a less extent the kidneys for storage. Some carotene also passes direct to the liver where it is stored before it is converted to vitamin A.

When dry pastures, hay and grains (except maize) are low in carotene content this ability of the animals to store vitamin A means that they usually have enough when there …

Macrobenthos Population Changes In Crystal Lake, Arkansas, Subsequent To Cage Culture Fish, James C. Adams, Raj V. Kilambi, William A. Wickizer, Arthur V. Brown

Journal of the Arkansas Academy of Science

A three-year study was conducted to determine the possible effects of cage culture of fish on the environment of Crystal Lake, Arkansas. The investigation consisted of three periods: pre- (November 1971-October 1972), during- (November 1972-October 1973), and post- (November 1973-October 1974) cage culture. Numbers and biomass of benthos per square meter for pre-, during-, and post-culture periods were 1353 (10.0g), 730 (8.8g), and 1028 (4.1g), respectively. Numerically, Chaoborus sp., Chironomidae, and Oligochaeta comprised more than 97%. Chaoborus was the most numerous organism before fish culture (>68%), but dominance shifted to the Oligochaeta (>58%) after culture.

Distributional Records Of Amphibians And Reptiles From Coastal Plain Of Arkansas, Edmond J. Bacon Jr., Zane M. Anderson

Journal of the Arkansas Academy of Science

Distribution of amphibians and reptiles in the West Gulf Coastal Plain and Mississippi Alluvial Plain is not well known because extensive collecting has not been done in these areas and data in museums have not been published. New distributional records for three salamanders (Desmognathus fuscus brimleyorum, Manculus quadridigitarus, Plethodon glutinosus glutinosus) , two anurans (Rana areolata circulosa, Scaphiopus holbrooki holbrooki), and one snake (Lampropeltis doliata amaura) are presented. Additional collecting will be necessary to determine the exact range and status of the secretive species.

Continuation Of Mourning Dove Studies In Clark County, Arkansas, With Emphasis On Cyclical Behavioral Patterns, Thurman Booth, Fred L. Burnside Jr., Jan Burnside, Peggy Rae Dorris

Journal of the Arkansas Academy of Science

In conjunction with the U.S. Department of Interior, Fish and Wildlife Service, the Henderson State University Biology Department has continued a study of mourning doves in Clark County, Arkansas, with emphasis on cyclical behavioral patterns. Three hundred forty-three mourning doves were baited, trapped, and banded to obtain information concerning age, sex, populations, retraps, abnormalities, migrations, trap injuries, cyclical behavioral patterns, and other factors.

Characteristics And Behavior Of Guineafowl And Domesticated Chicken Hybrids, Earl L. Hanebrink

Journal of the Arkansas Academy of Science

The description, behavior, and morphologic measurements are presented for two hybrid crosses of domesticated chicken and guineafowl. The ease at which gallinaceous birds hybridize might warrant a closer look at the classification system. Possibly the number of families in the superfamily Phasianoidea should be reduced as some other researchers suggest.

Hormone Receptor Site Maturation In The Secondary Sex Organs Of Immature Male And Female Rats, K. J. Thomas

Journal of the Arkansas Academy of Science

The effect of a combined dose of pregnant mares' serum (PAAS) and human chor ionic gonadotropin (HCG) on male and female rats 2-25 days old was studied. Groups of animals were given injections for three days, then sacrificed on the fourth day. All injections were begun on the 2nd, 7th, 12th, 17th, and 22nd day of life. Ovaries, uteri, seminal vesicles (SV), and ventral prostate (VP) were removed, dissected free of fat, and weighed. Because uterine weight increased earlier than either SV or VP weight, the ability of the uterus to respond to exogenous estradiol and of the SV and …

Free Fatty Acids Associated With Induced Rancidity In Cream And Butter, John Alan Anderson

Electronic Theses and Dissertations

One of the most significant problems in the dairy industry today is the flavor defect known as rancidity. This defect has been recognized for some time, but recent trends in milk handling have increased the problem of rancidity. Recently the dairy industry on the farm has changed to the increased use of pipeline milkers and bulk handling of milk. Processing plants are becoming larger and more centralized, resulting in more movement over longer distances for the raw product. These changes result in increased foaming and agitation of the milk, contributing to the rancidity problem. The butter industry has changed. Butter …

Physiologic And Embryologic Studies Of The Yellow (Ay/A) Mouse, Gerald R. Cizadlo

Electronic Theses and Dissertations

Mice heterozygous for the dominant AY gene have a yellow coat plus an altered metabolism which results in diverse physiologic characteristics including a greatly increased amount of carcass fat, a longer body and tail length, slightly more muscle mass, increased feed efficiency, increased susceptibility to spontaneous and induced tumor growth, and reproductive inefficiency in females. Homozygous AY animals die in utero. The mutation produces a lesion which is potentially valuable as an investigative· tool for the study of physiologic mechanisms and relationships of diverse metabolic pathways. Several experiments were performed to gain information concerning the AY effect. Rate of oxygen …

Mathematical Models Of Postweaning Growth, Feed Intake And Carcass Composition Of Beef Cattle, Hoon Song

Electronic Theses and Dissertations

A computer model was developed to evaluate the energetic efficiency of postweaning beef production of various biological types of cattle fed rations with different energy densities. In Section I, a mathematical model was developed to estimate voluntary feed intake for growing cattle from weaning to slaughter. The mathematical model included effects of differences in energy density and crude fiber content of the ration and in breed and degree of maturity of cattle on feed intake. When gastrointestinal tract distension controlled feed consumption, the primary factors determining feed intake were (1) rate of excretion of digesta, (2) rate of digestion, (3) …

Scanning Electron Microscopy Of The Rainbow Trout (Salmo Gairdneri Richardson) Spermatozoon, James H. Fribourgh, Bernard L. Soloff

Journal of the Arkansas Academy of Science

The scanning electron microscope was used to determine the morphology of the rainbow trout (Salmo gairdneri Richardson) spermatozoon. The spermatozoon is approximately 32 μm long and consists of a head, mitochondrial collar, and flagellum. The head is elongated and somewhat flattened. It has an antero posterior length of 3.1 μm and a maximum diameter of 1.6 to 2.2 μm. Mean antero-posterior length of the mitochondrial collar is 0.8 μm The collar encircles the flagellum but is separated from it. The flagellum ranges in length from 26 to31 μm and is divided into a principal piece and end piece. Cytoplasmic vesicles …