| Abstract: | The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100 cm in diameter, 15 cm water depth) were conducted to determine whether fish density (low = 2, medium = 4, high = 6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated a hierarchy based on aggressive interactions, but ruffe were most aggressive at low and high fish densities. Time spent in foraging was lowest at the low fish density. The best forager at the low fish density was the most aggressive individual, but the second most aggressive fish at the medium and high fish density was the best forager and also the one chased most frequently. A medium fish density offered the best energetic benefits to ruffe by providing the lowest ratio of time spent in aggression to that spent foraging. Based on our results, ruffe should grow best at an intermediate density. With high ruffe densities, we would also expect disparity in size as the more aggressive fish are able to garner a disproportionate amount of the resources. Alternatively, as the Great Lakes are a fairly open system, ruffe could migrate out of one area to colonize another as populations exceed optimal densities. |
| Genre: | Article |
| ProdID: | 1000858 |
| Citation Author: | Savino, Jacqueline F.; Kostich, Melissa J. |
| Citation Contributing Office: | Great Lakes Science Center |
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| Citation End Page: | 345 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Environmental Biology of Fishes |
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| Citation Number Of Pages: | 9 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | 9 p. |
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| Citation Publisher: | Springer |
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| Citation Search Results Text: | Aggressive and foraging behavioral interactions among ruffe; 2000; Article; Journal; Environmental Biology of Fishes; Savino, Jacqueline F.; Kostich, Melissa J. |
| Citation Start Page: | 337 |
| Citation Volume: | 57 |
| Citation Year: | 2000 |
| Type: | citation/reference |
| Text: | Aggressive and foraging behavioral interactions among ruffe; 2000; Article; Journal; Environmental Biology of Fishes; Savino, Jacqueline F.; Kostich, Melissa J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1023/A:1007523307404 |
| Date Other: | Sat, 1 Jan 2000 00:00 -0600 |
| Publisher: | Springer |
