Atelopus limosus, the limosa harlequin frog[3] (Spanish: sapo limoso[1]) is an endangered species of toad in the family Bufonidae endemic to Panama.

[4] Its natural habitats are stream banks in tropical moist lowland forests and rivers of the Chagres watershed in central Panama.

Little is known of their diet in the wild, but it is presumably similar to that of other Atelopus species that forage on beetles, ants, flies, and mites.

[6] Worried about the effects of chytridiomycosis on this endemic Panamanian frog, the Panama Amphibian Rescue and Conservation Project targeted A. limosus as a priority rescue species to be taken into captivity as an assurance colony at the Summit Municipal Park in Panama City.

When the rescue team arrived at one of the last known upland sites at Cerro Brewster, they found many of the frogs were already infected with chytridiomycosis.