We describe the food web dynamics of fishless lentic communities of montane east-central Arizona. We highlight the changing trophic status of a top predator, larval tiger salamanders (Ambystoma tigrinum nebulosum), using long-term dietary information on different age classes and populations. Larvae are on the third trophic level when <30 mm snout-vent length (SVL) eating predominantly daphnids and dipteran larvae. This pattern appears to be true regardless of whether larvae will develop into typical or cannibalistic morphs. Beyond 30 mm SVL, A. t. nebulosum larvae eat a greater variety and range of sizes of aquatic insects and are on the fourth trophic level with larval predaceous diving beetles, Dytiscus dauricus and D. marginicollis, and leeches. Interactions between these predators are complex, changing with ontogeny and density. Cannibalistic salamander morphs and adult Dytiscus are on the fifth and highest trophic level in the freshwater ecosystem. Conspecifics comprise about 84% of the diet of cannibalistic morphs. Only one typical morph of 418 analyzed in this study ate a conspecific. However, above ≈65 mm SVL, typical salamander morphs are too large to be eaten by cannibalistic morphs and beetles. The food web is species-rich and dominated by relatively small, invertebrate and vertebrate ectotherms.