Abstract
On the occasion of only its second filling this century, Lake Eyre was sampled seven times between July 1974 (when the minimum salinity value of 7%, was obtained) and April 1975 (salinity 40%,). The dominant zooplanktonic forms recorded were Moina mongolica (first Australian record), Apocyclops dengizicus, Diacypris, Hexarthra fennica and Brachionus plicatilis. It is thought that Daphniopsis pusilla was prevented from obtaining significant numbers because its relatively large size made it vulnerable to fish predation. The most significant phytoplanktonic genera recorded were Nodularia, Anabaenopsis and Glaucocystopsis.