Periphytic rotifer communities of an Australian seasonal floodplain pool

Murray-Darling Freshwater Research Centre

MDFRC item.

A seasonal, rainfill pool (Ryans 3) on the floodplain of the River Murray, near Albury, Australia was sampled in 1991 and 1993 for periphytic rotifer species and other microfauna. The main macrophytes present were species of Myriophyllum, Pseudoraphis and Triglochin, and, in 1993, there was an extensive covering of Azolla. Sampling methods included quantitative samples taken using a simple syringe. Rotifers numbered from about 10 to 150 per 100 ml and formed about 2 to 20% of the microfaunal community. Numbers of rotifers, and numbers of rotifer species, varied with different macrophytes (chi(2) tests, P<0.001 in each case), with the greatest numbers under Azolla. The two years showed marked differences in the macrophytes present and over half the rotifer species were also different (chi(2) test, P<0.001).