Pumiliotoxin 251D is a toxic organic compound. It is found in the skin of poison frogs from the genera Dendrobates, Epipedobates, Minyobates, and Phyllobates and toads from the genus Melanophryniscus. Its name comes from the pumiliotoxin family (PTXs) and its molecular mass of 251 Daltons. When the toxin enters the bloodstream through cuts in the skin or by ingestion, it can cause hyperactivity, convulsions, cardiac arrest and ultimately death. It is especially toxic to arthropods (e.g. mosquitoes), even at low (naturally occurring) concentrations.