Trophic relationships of the platypus: insights from stable isotope and cheek pouch dietary analyses

摘要: The unique Australian monotreme, the platypus (Ornithorhynchus anatinus) potentially exerts a strong top-down influence on riverine food webs in eastern Australia. However, despite considerable interest evolutionary history and physiology of platypus, little is known its trophic relationships. To address this lack knowledge we used stable isotope analysis, combination with analysis items stored cheek pouches, to determine position typical web. This was essential first step process designing larger study investigate relative importance bottom-up effects rivers where occurs. We found that platypuses were feeding wide range benthic invertebrates, particularly insect larvae. similarity δ13C δ15N values recorded for native fish (Galaxias sp.) exotic mosquitofish (Gambusia holbrooki) indicated dietary overlap potential competition same resources. Although pouch studies identify most major groups prey organisms, contribution soft-bodied organisms such as larval dipterans, suggested by indicating use both techniques will be important future ecological investigations.