Abstract
We investigated the effect of temperature on gastric evacuation rate and growth at ration of ruffe Gymnocephalus cernuus because of its importance for estimating food consumption by this invasive nuisance species. Gastric evacuation rate was estimated at 8, 14, 19, and 23°C using groups of 16–48 fish that were fed chironomid larvae, an important prey species for many ruffe populations. Growth at ration was estimated at 14, 19, and 23°C for daily rations of 2, 4, and 8% of body mass using groups of 7–8 fish. Gastric evacuation rate (R) was related to temperature (T) by the exponential function R = 0.024 × e0.075 × T; r 2 = 0.90. Between 8°C and 23°C, the magnitude of the temperature response of R was less for ruffe than for yellow perch Perca flavescens and European perch P. fluviatilis, but the European perch and ruffe R versus temperature functions intersected at approximately 4°C. Growth of ruffe ranged from −0.24 to 0.55% of wet body mass per day, increased with ration, and declined with increasing temperature. Our results suggest that, compared with perch, ruffe are better adapted to cooler temperatures and that their metabolism is less sensitive to temperature.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 552-560 |
| Number of pages | 9 |
| Journal | Transactions of the American Fisheries Society |
| Volume | 129 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 2000 |
Bibliographical note
Funding Information:We thank Jay Maher, Peter Sorensen, Peter Man-iak, and Christopher Appelt for loaning us their facilities, for their advice, and for their assistance in obtaining and housing fish, and we thank Franz Hölker for advice and discussion. We also thank undergraduate research assistant Tom Anderson for helping to care for the fish, Sanford Weisberg for statistical advice, and David Middleton and Edward Rutherford for commenting on the manuscript. This work is the result of research sponsored by the Minnesota Sea Grant College Program (supported by the National Oceanic and Atmospheric Administration, Office of Sea Grant, U.S. Department of Commerce) under grant US-DOC-NA46RG0101 (C. Richards, PI). Additional support was provided by the Minnesota Agricultural Experiment Station under project 74. The U.S. Government is authorized to reproduce and distribute reprints for government purposes, not withstanding any copyright notation that may appear hereon. This paper is journal reprint JR 454 of the Minnesota Sea Grant College Program and paper 984410019 of the contribution series of the Minnesota Agricultural Experiment Station.