Effect of temperature and roach Rutilus rutilus group size on swimming speed and prey capture rate of perch Perca fluviatilis and R rutilus
Linlokken, A.N.; Bergman, E.; Greenberg, L.
Journal of Fish Biology 76(4): 900-912
2010
ISSN/ISBN: 0022-1112
DOI: 10.1111/j.1095-8649.2010.02545.x
Accession: 037415270
Effects of temperature and group size of roach Rutilus rutilus on foraging behaviour of perch Perca fluviatilis and R. rutilus were tested in two laboratory experiments. A temperature experiment with P. fluviatilis and R. rutilus in aquaria (with either one P. fluviatilis or two R. rutilus) was tested at five temperatures: 4, 8, 12, 16 and 20deg. C, and showed that P. fluviatilis had a lower swimming speed and capture rate than R. rutilus, especially at 4 and 8deg. C. The effect of group size was tested at four R. rutilus abundances: 0, 2, 4 and 6, all at 16deg. C, and revealed that swimming speed and capture rate of P. fluviatilis were lowest at the highest R. rutilus abundance, whereas R. rutilus was relatively unaffected. Perca fluviatilis occupied positions closer to the bottom than R. rutilus, especially when feeding, and this tendency was reinforced at the highest roach abundance.