Barred Tiger Salamander cannibal larvae with typical larvae in its mouth

Barred Tiger Salamander larva with typical larva in its mouth, Kidder County, ND. 

Cannibal morphs are typically larvae and are distinguished by their disproportionally larger heads and  pronounced vomerine teeth. They get their name from their tendency to eat other barred tiger salamander larvae. The "cannibal" morphology provides a competitive advantage by allowing them to utilize a new prey/energy source (each other) and grow to metamorphosis. The duration and amount of water in a wetland and the availability of invertebrate prey are very important predictors of salamander morphology. Cannibal morphs are typically found in small, drying wetlands where salamanders all compete for limited prey resources.