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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.

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 …

Herpesvirus Disease Of Salmonids, Ken Wolf, Tokuo Sano, Takahisa Kimura

United States Fish and Wildlife Service: Publications

A newly recognized virus, lethal for fry and fingerlings, has been isolated from brood stock rainbow trout (Salmo gairdneri) at the Winthrop National Fish Hatchery, Washington. A similar if not identical virus has been found in natural epizootics occurring annually since 1970 among fry of landlocked sockeye salmon (Oncorhynchus nerka) on Honshu Island, Japan. More recently, this agent was isolated from moribund and dead adult O. nerka on Hokkaido Island; Japan, but it remains to be determined whether or not the virus causes death in adult salmonids. The purpose of this leaflet is to bring the …

A Disease Of Freshwater Fishes Caused By Tetrahymena Corlissi Thompson, 1955, And A Key For Identification Of Holotrich Ciliates Of Freshwater Fishes, Glenn L. Hoffman, M. Lando, J. E. Camper, D. W. Coats, J. L. Stookey, J. D. Burek

United States Fish and Wildlife Service: Publications

Tetrahymena corlissi, a free-living protozoan, apparently caused the death of large numbers of guppies (Poecilia reticulatus) and occasionally other fishes, in aquaria and hatcheries at several locations. Apparently the disease occurs when the fish and protozoan populations are both at a high level of density. The signs include white spots and epidermal damage. Histologically, T. corlissi could be seen in skin, muscle, and viscera; in some there was marked inflammation, in others there was little tissue reaction. A key is presented for the identification of invasive fish ciliates: Chilodonella, Hemiophrys, Ichthyophthirius, Ophryoglena, and Tetrahymena.

Finitely Generated Modules Over Bezout [email protected], Roger Wiegand, Sylvia Wiegand

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Let R be a Bezout ring (a commutative ring in which all finitely generated ideals are principal), and let M be a finitely generated R -module. We will study questions of the following sort: (A) If every localization of M can be generated by n elements, can M itself be generated by n elements? (B) If M 0 R m = Rn for some m, n, is Af necessarily free? (C) If every localization of M has an element with zero annihilator, does M itself have such an element? We will answer these and related questions for various familiar classes …

Review Of Parasites Of Freshwater Fishes, Ross F. Nigrelli

United States Fish and Wildlife Service: Publications

The title of this paperback should be "The Treatment and Control of Parasites of Freshwater Fishes," since a therapeutic armamentarium is its chief feature. This information, which was collected from many, often obscure, sources, is the most comprehensive collection of data on the subject that has ever been assembled and published. As pointed out by Drs. Hoffman and Meyer, two outstanding authorities on fish diseases, the efficacy of many of the chemicals listed has not been critically evaluated, and some of them should be used with caution. To this end, they have included a table which gives the toxicity limits …

Polypodium Sp. (Coelenterata) Found In North American Sturgeon, Glenn L. Hoffman

United States Fish and Wildlife Service: Publications

On 27 May 1970, Mason Shouder, Michigan Fisheries Biologist, discovered some abnormal eggs in a ripe sturgeon, Acipenser fulvescens. The fish were taken from the Black River near Cheboygan, Michigan, which is barricaded from Lake Huron by a dam built in the 1920's. Normal ripe eggs were black spheres; the abnormal ones were enlarged and grayish (Fig. 1). About 20% of the eggs were affected and attached to the wall of the uterus in saclike structures. The ovary was also abnormal, being flaccid. In May 1973, a single infected egg was found in vodka-prepreserved eggs from a ripe sturgeon …

Review Of Parasites Of Freshwater Fishes

United States Fish and Wildlife Service: Publications

This is a well organized, clearly written review of fish parasite control and treatment methods. The authors, who are renowned specialists in the field, have drawn together more than 390 up-to-date references and over 440 treatments. The treatments are discussed for each major parasite group in a handy chart form that greatly facilitates the book's usefulness. Interspersed between the charts are full-page or half-page color plates illustrating the parasites and the appearance of their infections in fish. There are 108 illustrations (all but 2 in color) on 57 pages, constituting more than 25% of the book's length and resulting in …

Review Of Fish Pathology: A Guide To The Recognition And Treatment Of Diseases And Injuries Of Fishes, With Emphasis On Environmental And Pollution Problems And Parasites Of Freshwater Fishes: A Review Of Their Control & Treatment, Ross F. Nigrelli

United States Fish and Wildlife Service: Publications

Fish Pathology states in its subtitle that it is "A guide to the recognition and treatment of diseases and injuries of fIshes with emphasis on environmental and pollution problems." These topics were included in the author's earlier volume "Krankheiten und Schadigungen der Fische" (Gustav Fischer Verlag, Stuttgart, 1966) and are only slightly revised in . this English translation by Christa Ahrens. Fish Pathology deals briefly but inadequately with semiology and histopathologY but it is a good introduction to information on infectious, parasitic, and nonparasitic diseases of fishes, and to such subjects as the harmful effects of pollutants and abnormal environmental …

Parasites Of Some Penaeid Shrimps With Emphasis On Reared Hosts, Robin M. Overstreet

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Information is presented about parasites and commensals of penaeid shrimps, allowing those who rear shrimps and those who are interested in associated organisms of shrimp to have a better knowledge of the organisms that are or may be associated with brown, white, and pink shrimps. It covers common and rare organisms and diseases, primarily in the northern Gulf of Mexico, listing several previously unreported species including an undescribed gregarine, a larval nematode (Spirocarnallanus pereirai), a commensal nematode (Leptolaimus sp.), a leech (Myzobdella lugubris), a blue-green alga (Schizothrix calcicola), a hydroid (Obelia bicuspidata …

Critical Flicker Frequency In A Harp Seal, Pagophilus Groenlandicus (Erxleben, 1777), Charles D. Bernholz

University of Nebraska-Lincoln Libraries: Faculty Publications

Critical flicker frequency (CFF) in a free-swimming harp seal (Pagophilus groenlandicus) was investigated using behavioral techniques. The resulting CFF versus intensity contour indicates a definite rod-cone break, confirming a duplex photoreceptor population whose presence had not been observed in previous morphological reports.

Review Of Check List Of The Helminth Parasites Of African Freshwater Fishes, Glenn L. Hoffman

United States Fish and Wildlife Service: Publications

In spite of the fact that freshwater covers about 74,000 square miles of Africa, surprisingly little work has been done on the helminth parasites of African fishes. This well written and documented book consists of excellent parasite/host and host/ parasite check lists followed by indices of parasites and countries. As the author stated, "It is hoped that this list, combined with the increasing recognition of the importance of fish as a source of protein and, therefore, of the significance of potential pathogens, will provide the necessary stimulus to research workers to rectify these gaps."

Morphology Of The Spores Of Myxosoma Cerebralis (Hofer, 1903) And M. Cartilaginis (Hoffman, Putz, And Dunbar, 1965)*, Glenn L. Hoffman, Jiří Lom

United States Fish and Wildlife Service: Publications

The spore of Myxosoma cerebralis is redescribed and compared with that of a close relative, M. cartilaginis. M. cerebralis is smaller, with greater variability in size and shape. It possesses a mucous envelope whereas M. cartilaginis does not. The surface architecture of M. cerebralis, as seen with the scanning electron microscope, differs in possessing a conspicuous circumsutural groove, prominent polar filament pores, and a mucous envelope.

Bibliography Of Diseases And Parasites Of Marine Fish And Shellfish (With Emphasis On Commercially Important Species), Carl J. Sindermann

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The literature on diseases and parasites of marine animals has been accumulating at an accelerating rate in recent decades, and at a seemingly geometrical rate in the past few years. Reviews of selected aspects of the subject have appeared (Cheng, 1967; Sindermann, 1966; Sindermann and Rosenfield, 1967). References listed in these papers include a significant, but still a small part, of the available literature. With the proliferation of journals in many languages throughout the world, a complete bibliography, even in a narrow area of research, is almost an impossibility. Then too, the daily appearance of new published information represents an …

Some Ecological Relations Of Fairy Shrimps In Alkaline Habitats Of Nebraska, D. B. Mccarraher

Nebraska Game and Parks Commission: Staff Research Publications

Ecological studies on the distribution of fairy shrimps have been made from 246 sites in the sandhills region of Nebraska. New records for Nebraska have been established for Artemia salina, Branchinecta campestris, B. lindahli, B. mackini and Cyzicus mexicanus. Seasonal populations of shrimp have been located in habitats containing permanent fish populations. Water mineralization was the dominant environmental condition related to the distribution of phyllopods with sodium and potassium compounds predominating in the strongly alkaline lakes. Several of the Artemia lakes were classified as hydroxide sites. Many of the alkaline ponds, where B. lindahli and B. campestris flourish, are …

A New Genus Of Trematode (Digenea: Gorgoderidae) From The Ureter Of Tuna Fish (Thunnus Thynnus Maccoyii) In Australia, Harold W. Manter

Harold W. Manter Laboratory of Parasitology: Library Materials

A large, digenetic trematode is described from the ureter of the tuna Thunnus thynnus moccoyii from southern Australian waters. It represents a new genus and species, Cetiotrema crassum (subfamily Gorgoderinae) distinguished by the size and shape of the body, the caeca being distant from the sides of the body, the uterus being intercaecal, the vitellaria arising as three claviform lobes on each side and the seminal vesicle at least partly anterior to the genital pore.

The genus is close to Phyllodistomum Braun; P. carangi Manter, 1947, is considered to belong to Cetiotrema; P. lancea Mamaev, 1968 is very similar …

Phlyctainophora Squali Sp. Nov. (Nematoda, Philometridae) From The Spiny Dogfish, Squalis Acanthias, Dwight R. Mudry, Murray D. Dailey

Harold W. Manter Laboratory of Parasitology: Library Materials

Summary

Phlyctainophora squali sp. nov. is described from 23 female specimens recovered from the subcutaneous tissue of one of 440 Squalis acanthias caught off Los Angeles, California. This finding represents a new host and distribution for this genus. Phlyctainophora is placed in the family Philometridae on the basis of atrophication of vulva and anus, simple mouth, viviparity and location in tissue of fishes. The family diagnosis for Philometridae is amended to include Phlyctainophora which lacks an anterior ovary.

Mourning Dove Status Report, 1967, James L. Ruos, Duncan Mcdonald

United States Fish and Wildlife Service: Publications

Nationwide dove population indexes in the 1967 Mourning Dove Status Report were obtained by essentially the same data gathering and analyzing procedures as in 1966. A refinement was made in the base year index, using the mean of the 1966 and 1967 readings as the base for all States. There was a slight adjustment in physiographic region boundaries.

Reviews Of Glenn L. Hoffman (1967). Parasites Of North American Freshwater Fishes., John Paling

United States Fish and Wildlife Service: Publications

'This manual', the author explains, 'is intended to be an aid to the identification of the freshwater fish parasites of North America'. Judged by this objective, the book will be an invaluable source of reference for workers in this field. However as it does not set out to cover the ecology of fish parasites and furthermore as it concerns itself mainly with the American fauna, this book will probably have only a limited appeal to readers of this Journal.

Review Of Parasitology: Parasites Of North American Freshwater Fishes, Brother George Paul

United States Fish and Wildlife Service: Publications

This book is intended to serve as a manual for aiding in the identification of the freshwater fish parasites of North America. To this end an extensive key is given for each of the biological groups that have a notable number of fish parasites. In addition to this, there are sections devoted to such topics as: procedures for examining fish for parasites, methods of preserving and preparing parasites for analysis, a check list of parasites of each species of fish, and an extensive bibliographical list of references.

In Memoriam Ralph Vanderwort Bangham, 1895-1966, Glenn L. Hoffman

United States Fish and Wildlife Service: Publications

The council notes with regret the passing of Dr. Ralph Vanderwort Bangham who died at his home in Wooster, Ohio, on 26 February 1966 at the age of 71. Dr. Bangham was one of the pioneers in the field of fish parasitology in the United States.

Review Of Key To Parasites Of Freshwater Fish Of The U.S.S.R., Glenn L. Hoffman

United States Fish and Wildlife Service: Publications

This is a translation of the Russian book, Opredelitely Parazitov Presnovodnykh Ryb SSSR, by the above authors, Izdatel'stvo Akademii Nauk SSSR, Moscow-Leningrad, 1962. It is essentially a key to the identification of the species of parasites of the freshwater fishes of Russia including longer descriptions of the higher taxa.