Diagnosis:The species cannot be distinguished from O. gracilis and O. uniformis morphologically, but major differences are recognized genetically. Moderately sized grayish-black salamander (adults 108 to 175 mm TL) with a very long tail (64 to 72% of TL). The head is moderately broad and the snout is bluntly rounded. Maxillary teeth 32 to 43 in count. This species has short legs with tiny hands and feet. Costal grooves number 19 to 20 (Savage 2002).
Description:Oedipina pacificensis is a worm salamander of the family Plethodontidae (the "lungless salamanders"). The body is extremely slender and elongate with short limbs and tiny hands and feet (Savage 2002). Hands and feet are syndactylous with four toes on forelimbs and five toes on hindlimbs. The tail is very long (64% to 72% of total length) (Savage 2002). The snout-vent length of an adult male is generally 26 to 48 mm and adult females are 39 to 51 mm in standard length (Savage 2002). Adults are 108 to 175 mm in total length (Savage 2002). Salamanders of this species have 19 to 20 costal grooves on the sides of its bodies (Savage 2002). This species has a moderately broad head with a bluntly rounded snout (Savage 2002). A sublingual fold is present (Savage 2002). There are 32 to 43 maxillary teeth present and 20 to 26 vomerine teeth (Savage 2002). Oedipina pacificensis is grayish-black in color, often with a whitish area near limb insertions or joints (Savage 2002). This species also has white post-ocular stripes (Taylor 1952). It cannot be distinguished morphologically from O. gracilis and O. uniformis, but there are major genetic differences for O. pacificensis (Good and Wake 1997).
This species was first described by Taylor (1952), but was then subsumed by Brame (1968) into O. uniformis. Subsequently, Good and Wake (1997) described O. uniformis genetic differentiation and recognized O. pacificensis as a cryptic species.
A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).