| Abstract: | In laboratory studies, we quantified predation rates of crayfish (Orconectes virilis) on the eggs and sac fry of lake trout (Salvelinus namaycush) and a surrogate species, rainbow trout (Oncorhynchus mykiss), dispersed among different sized substrates (bare bottom, gravel, cobble, large rocks). Predation was most severe when no rocks were present. Feeding rate then decreased as the substrate changed from large rocks to cobble to gravel. Crayfish predation rate did not change with prey type -- rainbow trout and lake trout eggs or sac fry. Crayfish foraging in large tanks containing cobble averaged about two eggs or sac fry per day. In most instances, crayfish would have little impact on lake trout egg survival. Only in lake trout spawning grounds with relatively low egg densities, large crayfish populations, and cobble or large rock substrate, would crayfish be expected to have some impact on lake trout egg survival. |
| Genre: | Article |
| ProdID: | 1000587 |
| Citation Author: | Savino, Jacqueline F.; Miller, John E. |
| Citation Contributing Office: | Great Lakes Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 170 |
| Citation Issue: | 2 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Journal of Freshwater Ecology |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 9 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | p. 161-170 |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Crayfish (Orconectes virilis) feeding on young lake trout (Salvelinus namaycush): effect of rock size; 1991; Article; Journal; Journal of Freshwater Ecology; Savino, Jacqueline F.; Miller, John E. |
| Citation Start Page: | 161 |
| Citation Volume: | 6 |
| Citation Year: | 1991 |
| Type: | citation/reference |
| Text: | Crayfish (Orconectes virilis) feeding on young lake trout (Salvelinus namaycush): effect of rock size; 1991; Article; Journal; Journal of Freshwater Ecology; Savino, Jacqueline F.; Miller, John E. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 1991 00:00 -0600 |
| Publisher: | |
