The Pacific mud eel[1] (Pythonichthys asodes) is an eel in the family Heterenchelyidae (mud eels).[2] It was described by Richard Heinrich Rosenblatt and Ira Rubinoff in 1972.[2] It is a tropical, marine eel which is known from the eastern central Pacific Ocean, including Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Panama, and Nicaragua.[3] It dwells at a maximum depth of 17 metres, typically habituating muddy substrates in estuaries. It is able to survive in water with a low salt concentration.[3] Males can reach a maximum total length of 47.2 centimetres.[2] The eels' diet consists primarily of benthic gastropods and worms, and bivalves.[3]
Due to its wide distribution, lack of threats and lack of observed population declines, the IUCN redlist currently lists the Pacific mud eel as Least Concern.[3]