Diet of the newt, Triturus carnifex (Laurenti, 1768), in the flooded karst sinkhole Pozzo del Merro, central Italy

Abstract

Karst habitats host a high number of specialized organisms that contribute to complex and peculiar food webs. In underground aquatic habitats, vertebrates are the top predators that strongly influence and regulate prey communities. In this study, the diet of the Italian crested newt, Triturus carnifex, in the world's deepest karst phreatic sinkhole, the Pozzo del Merro in Latium, central Italy, was analyzed. We obtained both stomach and fecal contents from twenty adult newts (ten females and ten males) sampled in summer 2010. Availability of prey in the sinkhole also was determined. Prey items were identified and classified into ten ecological groups. At Pozzo del Merro, during the summer, the aquatic stage of T. carnifex was specialized on the pre-imaginal stages of the small China-mark, Cataclysta lemnata. The recently described endemic stygobitic crustacean Niphargus cornicolanus was not found in stomach contents. Finally, our results showed that analyses of stomach and fecal contents may provide different information on the diet of newts in their aquatic phase.