The Gila topminnow (Poeciliopsis occidentalis occidentalis) is federally and state listed as endangered. My objectives were to quantify microhabitat use and preference of topminnow in the field and test responses to controlled laboratory settings. In Cienega Creek, topminnow preferred stream margins where the water was calm, shallow, and contained aquatic vegetation. Topminnow were always near the water surface. Water temperature averaged 1-2 C warmer in areas occupied by fish. In outdoor pools, groups of topminnow consistently preferred cover provided over no cover and selected the upper 1/3 of the water column. Plastic strips, elicited the strongest response and styrofoam sheets elicited the weakest response. Topminnow did not show a consistent preference for cover when tested singly in aquaria, but showed a strong preference for calm water. Responses of topminnow to tests in aquaria were not in concordance with behavior observed in Cienega Creek or in tests conducted in outdoor pools.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/291708 |
| Date | January 1992 |
| Creators | Forrest, Robert Eugene, 1965- |
| Contributors | Matter, William J. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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