Atelopus oxyrhynchus is a species of toad in the family Bufonidae.

A. oxyrhynchus contains tetrodotoxin (TTX), a potent neurotoxin that induces muscle paralysis and/or death.

Unlike Atelopus varius, which do not retain TTX when raised in captivity and thus acquires TTX exogenously, A. oxyrhynchus maintains its toxicity when raised in captivity.

This has also been shown for the rough-skinned newt, Taricha granulosa.

These organisms raise questions about the source of TTX, as the most supported hypothesis for TTX toxicity in other animals is an exogenous origin, either through dietary uptake or bacterial symbiosis.