Throughout tropical Australia eulimnetic zooplankton is composed of 7 calanoid copepods, 5 cyclopoid copepods and 12 cladocerans . A further 10 cyclopoids and 9 cladocerans occur as littoral `strays', making 43 species in all . Dominants include Diaptomus lumholtzi, Mesocyclops notius, Thermocyclops decipiens, Diaphanosoma excisum, Ceriodaphnia cornuta, and Moina micrura. Momentary species composition averages 1 .0 calanoids, 1 .3 cyclopoids and 2 .0 cladocerans . These assemblages are not only less complex than in temperate Australia, but also are not as rich as in most other tropical regions . The main contributors to these differences are calanoids and cladocerans respectively . Nevertheless, as elsewhere, most zooplankters in tropical Australia are eurytropic, widely distributed and small .