Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 1840

James W. Moore; Some factors influencing the density and birth rate of three subarctic rotifer populations. Arch.Hydrobiol. 83(2):251-271, 1978

Reprint

In File

Notes

The effect of temperature, food supply, predation and photoperiod on the density of 3 rotifer populations was determined from collections made between June 1975 and November 1976 in the Canadian subarctic. Changing temperature accounted for 33-50% of the variation in Keratella earlinae and K. cochlearis while in Kellicottia longispina, Polyarthra spp., Asplanchna priodonta and Synchaeta stylata the respective values were 18-60, 45-73, 2-10, and 3-7%. Algal food supply had little effect on herbivorus rotifers but, in A. priodonta and S. stylata, prey availability accounted for 24-48% of density fluctuations. Of minor significance to all species were predation and photoperiod. Temperature usually accounted for >64% of the variation in the birth rate of Keratella spp. and K. longispina (the only species studied). The food Keratella spp. and K. longispina consisted of finely divided (<5 µm) detritus, associated bacteria and 0-20 algal cells/animal (mainly Cyclotella glomerata, Kepharion spp., Chlamydomans spp.). Bacteria were probably the main energy source.