DIET OF 2 FRESH-WATER TURTLES, CHELODINA-RUGOSA AND ELSEYA-DENTATA (TESTUDINES, CHELIDAE) FROM THE WET-DRY TROPICS OF NORTHERN AUSTRALIA

Chelodina rugosa occupies seasonally ephkmeral waterholes on the coast al freshwater floodplains of the wet-dry tropics of northern Australia , It is an obligate carnivore and feeds primarily on fish, fast-moving aquatic invertebrates, and carrion. Differences between wet-season an d dry-season diets, notably an increase in fish consumption and a decr ease in consumption of odonate nymphs, reflect changes in abundance or accessibility of prey items. Elseya dentata occupies permanent water riverine habitats and is primarily herbivorous. The bulk of its diet c onsists of fruit and leaves of riparian rainforest trees, and seasonal changes in fruit species consumed reflected fruiting patterns. Filame ntous algae comprised 30% by mass of the dry season diet but was absen t from the river during wet-season flooding and hence was absent from the diet. Elseya dentata readily feed on meat and fish carrion when av ailable, but animal prey such as shrimp (Macrobrachium sp.) and freshw ater sponge formed only a small proportion of their diet, Because E. d entata relies on riparian trees for most of its dietary intake, it is extremely vulnerable to land management practices that have adverse im pacts on riparian forests.