Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

1992

Ecology; Biology

Articles 1 - 2 of 2

Full-Text Articles in Entire DC Network

Influences On The Instream Distribution Of Astyanax Fasciatus In A Small River In Costa Rica., Cecil Kelly Swing Jan 1992

Influences On The Instream Distribution Of Astyanax Fasciatus In A Small River In Costa Rica., Cecil Kelly Swing

LSU Historical Dissertations and Theses

The instream distribution of the tetra, Astyanax fasciatus, was investigated through approximately 700 hours of field observations in a small Costa Rican stream on the southwestern Pacific coast near Golfito. Individuals tended to remain in particular pools where they subsisted primarily on a diet of terrestrial insects. These fish were able to migrate, and only as many individuals stayed in any pool as could be sustained there by available food resources. Because the water intercepted insects fairly uniformly over its surface, the biomass of fish occupying any particular pool was proportional to its surface area (r$\sp2$ = 0.652). The amount …


Ecosystem Models Of Aquatic Primary Production And Fish Migration In Laguna De Terminos, Mexico., Enrique Reyes Jan 1992

Ecosystem Models Of Aquatic Primary Production And Fish Migration In Laguna De Terminos, Mexico., Enrique Reyes

LSU Historical Dissertations and Theses

Laguna de Terminos is Mexico's largest coastal lagoon. There is a high habitat diversity including open water, mangroves, seagrasses and marshes, which supports Mexico's most economically important fisheries. Understanding ecosystem processes is essential for effective management of the lagoon's resources. This research developed landscape-level models for aquatic primary production (LAPPTER model), and fish migration (ROE model) in Laguna de Terminos. The ROE model was developed first as a theoretical approach, and later integrated into the LAPPTER model as a submodule which utilizes simulated production as a food source. The ROE model includes behavioral rules for fish movement based on environmental …