A new species of Leucostethus (Anura, Dendrobatidae) from Gorgona Island, Colombia.

We describe a new species of Leucostethus from Gorgona Island, a small (13 km2) island located 35 km from the Pacific coast of southern Colombia. The new species most resembles L.argyrogaster and L.fugax from western Amazonia at 340-870 m elev. in Peru and Ecuador, with which it shares pale ventral coloration and orange suffusion of the axilla, groin and concealed surfaces of the hind limb, but it is most closely related to L.bilsa from ca. 340 km SW in the southern Chocó at 420-515 m elev., northwestern Ecuador. We report miniscule white spots on the posteroventral surface of the thighs of the new species and, on the basis of our preliminary assessment of their taxonomic distribution, hypothesize that their presence is a synapomorphy of Dendrobatoidea with subsequent losses in a few groups. Given the apparent restriction of the new species to Gorgona Island, it is Vulnerable according to IUCN Red List criteria. In addition to naming the new species, we also propose the following new combinations: L.alacris (Rivero and Granados-Díaz, 1990) comb. nov., L.dysprosium (Rivero and Serna, 2000) comb. nov., and L.yaguara (Rivero and Serna, 1991) comb. nov.