Life Sciences Commons^™

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 …

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 …

Competition Between Color Morphs Of The Polychromatic Midas Cichlid Cichlasoma Citrinellum, George W. Barlow

Investigations of the Ichthyofauna of Nicaraguan Lakes

The Midas cichlid, Cichlasoma citrinellum, is a polychromatic fish that occurs in Nicaragua. All of these fish start life as normally colored, cryptic individuals. In some populations a few fish change into conspicuously colored morphs, most frequently gold. When kept in unmixed color groups, golds and normals grow at the same rate; but when they are mixed, growth of the golds becomes taster and that of the normals slower. Golds dominate normals in contests over food, which accounts for their advantage.

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 Behavior And Ecology Of Herotilapia Multispinosa (Teleostei, Cichlidae), Jeffrey R. Baylis

Investigations of the Ichthyofauna of Nicaraguan Lakes

Because of their complex social behavior and the ease with which they can be manipulated, cichlid fishes have long been of special interest to the ethologist. However, most of the research into cichlid behavior has been on Old World species. The social behavior of New World species is different and deserves more study. This paper will describe the ethology of one of the Central American cichlids, Herotilapia multispinosa.

Carcharhinus Nicaraguensis, A Synonym Of The Bull Shark, C. Leucas, Henry B. Bigelow, William C. Schroeder

Investigations of the Ichthyofauna of Nicaraguan Lakes

Nicaraguensis very closely resembles leucas by the following characters. The anterior margin of the eye is posterior to the front of the mouth by a distance equal to half its own diameter in nicaraguensis; the gill openings are relatively somewhat longer in nicaraguensis, the third being nearly as long as the distance between the nostrils; the free tip of the second dorsal is about two-thirds as long as its base in nicaraguensis.

Movement Of Bull Sharks, Carcharhinus Leucas, Between Carribean Sea And Lake Nicaragua Demonstrated By Tagging, Thomas B. Thorson

Investigations of the Ichthyofauna of Nicaraguan Lakes

The shark that occurs in the fresh water of Lake Nicaragua and the Rio San Juan was first described (as Eulamia nicaraguensis) by Gill and Bransford (1877). These authors also first proposed the theory that the sharks, as well as the sawfish and tarpon that occur in the lake, were trapped there by late Pleistocene volcanic activity, which isolated a former bay of the Pacific and resulted in the formation of the present lake. The theory of a landlocked, distinct species, of Pacific origin, has en joyed wide popular acceptance and for many years was also accepted by professional …

Calcium And Other Ions In Blood And Skeleton Of Nicaraguan Fresh-Water Shark, Marshall R. Urist

Investigations of the Ichthyofauna of Nicaraguan Lakes

The bull shark, Carcharhinus lellcas, employing archaic but effective means of regulating the physical-chemical composition of its body fluids, thrives in tropical fresh-water rivers and lakes. The ionic strength of the serum and the concentrations of total solutes, calcium, urea, and other ions are below the levels found in marine elasmobranchs but higher than the levels in teleosts. The patterns of the calcium deposits of the vertebrae are identical in marine and fresh-water subspecies.

Body Fluid Solutes Of Juveniles And Adults Of The Euryhaline Bull Shark Carcharhinus Leucas From Freshwater And Saline Environments, Thomas B. Thorson, C. Michael Cowan, Donald E. Watson

Investigations of the Ichthyofauna of Nicaraguan Lakes

Since the discovery of the phenomenally high urea content of the body fluids of cartilaginous fishes by Staedeler and Frerichs (1858), the unique osmoregulatory system of this vertebrate class has been studied by many investigators. In broad outline, the mechanisms are essentially similar in all three of the major subtaxa: the selachians, the batoids, and the holocephalans. A single exception is the genus Potamotrygon (fresh-water stingrays of South America and Africa), which has apparently lost the ability to concentrate urea even when transferred to salt water.

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.

Helminths From Elasmobranchs In Central American Fresh Waters, Donald E. Watson, Thomas B. Thorson

Investigations of the Ichthyofauna of Nicaraguan Lakes

Five species of monogeneans and 14 species of cestodes are reported from two elasmobranch species in fresh waters of Guatemala, Nicaragua and Costa Rica. Monogeneans from the bull shark, Carcharhinus leucas (Muller and Henle, 1841), are: Dermophthirius maccallumi n. sp. (Microbothriidae); Heteronchocotyle leucas Hargis, 1955 and Erpocotyle carcharhini n. sp. (Hexabothriidae). Cestodes from the bull shark are: Phyllobothrium lactuca van Beneden, 1850, P. leuci n. sp., P. nicaraguensis n. sp., Anthobothrium cornucopia van Beneden, 1850, A. laciniatum Linton, 1890 (Phyllobothriidae): Platybothrium hypoprioni Potter, 1937, Phoreiobothrium triloculatum Linton, 1901 (Onchobothriidae); Cathetocephalus thatcheri Dailey and Overstreet, 1973 (Cathetocephalidae); Dasyrhynchus variouncinnatus (Linton, 1924) …

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 …

Life-History, Ecology, And Behavior Of Liparis-Inquilinus (Pisces Cyclopteridae) Associated With Sea Scallop, Placopecten-Magellanicus, Kenneth W. Able, John A. Musick

VIMS Articles

No abstract provided.

Columnaris Disease Of Fishes, S. F. Snieszko, G. L. Bullock

United States Fish and Wildlife Service: Publications

Columnaris disease is a chronic to acute infection that affects salmonids and many species of warmwater fishes. The first description of the disease was given by Davis (1922) who named the disease and bacterium from the columnar arrangement of cells as seen in wet mounts. The bacterium causing columnaris disease was first isolated by Ordal and Rucker (1944). They identified the organism as belonging to the group known as slime bacteria or myxobacteria; because it produced fruiting bodies and microcysts, they named it Chondrococcus columnaris. Garnjobst (1945), who was unable to find fruiting bodies, renamed it Cytophaga columnaris. …

Memos And Reports On Shellfisheries In Virginia, 1972-1975, Jay D. Andrews

Reports

Compilation of 25 reports written between 1972 and 1975 summarizing the oyster industry and oyster research programs in Virginia.

• Seed Oyster Production on Seaside of Virginia
• Review of VIMS document on Eastern Shore fisheries
• Notes on National Fisheries Plan draft October 1974
• Soup oysters in Virginia
• Legislative needs of shellfisheries.
• Monitoring environmental stresses in York River.
• Oyster culture in York River
• Comments on MARAD waste treatment program
• Production of superior oysters for mariculture.
• Production of superior oysters for mariculture.
• Mollusk studies, Annual Report 1972-73
• Research goals and long-range programs
• Notes on black bottoms in Rappahannock River
• Oxygen depletion and black …

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 …

An Economic Appraisal Of Eastern Shore Seafood Harvesting, Ivar Strand

Reports

No abstract provided.

Oyster Spatfall On Shellstrings In Virginia Rivers: 1975 Annual Summary, Dexter S. Haven, Paul C. Kendall

Reports

The Virginia Institute of Marine Science (VIMS) conducts weekly surveys from June through early October to obtain oyster spatfall information. Spat counts are made from oyster shells strung on wire and · suspended from stakes on public and private beds. The number of spat on shells are counted each week of the spawning season to determine the potential of a particular area for receiving a strike and to predict the most likely period the strikes will occur. Shells .planted just before the period of maximum set have the best chance of getting a good strike.

Rare And Newly Recorded Chondricthyian And Teleostean Fishes Of The Continental Slope Of West Africa, G. A. Golovan

Reports

This paper is composed primarily of species descriptions and accounts, and as such contains a very large number of abbreviations and numerals in the text. Inasmuch as the material presented in this form is central to the content of the paper, very great care was taken in transposing and checking this information between this translation and the original Russian version.