Long Tailed Worm Salamander

Oedipina gracilis has an elongated body and tail, and its appendages are minuscule, giving it the appearance of an earthworm. Typically it can reach up to 75 mm SVL, or 210 mm including the tail. (Guyer and Donnelly 2005; Leenders 2001). When the tail is fully grown and not broken off, it can be up to three times the length of its body. All Oedipina have 17 to 22 costal grooves and 18 to 23 trunk vertebrae (Leenders 2001; García-París and Wake 2000). There is no difference in size between the Oedipina sexes (Bruce 2000). The body is uniformly dark brown, black or gray in color (Guyer and Donnelly 2005). If the tail breaks off and regrows, the regenerated part may be lighter (Guyer and Donnelly 2005). It is difficult to distinguish O. gracilis from the other members in its genus, because differences in limb length and number of teeth can be problematic to ascertain in the field. Oedipina gracilis is particularly similar to O. uniformis and the two species were previously synonymous, but significant genetic differences were found by Good and Wake (1997). When compared side by side, Oedipina gracilis is not as robust; it has a narrower head, a less rounded snout, and shorter, more slender hind legs than O. uniformis (Guyer and Donnelly 2005).This species was considered no longer synonymous with Oedipina uniformis by Good and Wake (1997). Of plethodontid salamanders, Oedipina have the most highly derived karyotypes. Including the X chromosome, Oedipina have two telocentric pairs of chromosomes, which are derived from biarmed ancestral chromosomes (Sessions and Wiktorowski 2000).A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio) (http://darnis.inbio.ac.cr/FMPro?-DB=UBIpub.fp3&-lay=WebAll&-Format=/ubi/detail.html&-Op=bw&id=4359&-Find).

These salamanders are distributed from low to high elevation (3-710 m) in Costa Rica along the Caribbean coast and in to Panama (Guyer and Donnelly 2005; Savage 2002). They are terrestrial and inhabit predominantly moist, hidden environments, such as leaf litter, burrows made by insects, and underneath or near rotting logs (Leenders 2001).

These salamanders are quite elusive and individuals are usually seen as a quick disappearing flash. They are nocturnal and fossorial. Not much is known about the reproductive cycle. The eggs are typically laid where adults frequent: under leaf litter or decaying logs. The amount of care devoted to offspring can only be speculated; however, other members of the genus Oedipina are not associated with parental care (Bruce 2003). When males become reproductive, it is thought that their maxillary teeth go through an enlarging period. This is a trait of other members of the lungless salamander family, Plethodontidae (Guyer and Donnelly 2005). Many species in the genus Oedipina have long glands on their chins called mental glands (mental is derived from the Latin word mentum, meaning chin), which develop at the same time the maxillary teeth enlarge. These glands secrete pheromones that are thought to make the female more receptive for mating. The maxillary teeth enlarge to better scrape the skin of the female. Pheromones from the male's mental gland, underneath his chin, are thought to be transferred more directly into the female bloodstream as a result of the scraping (Sever 2003).

Oedipina gracilis is a species of salamander in the family Plethodontidae. It is found in Costa Rica and Panama. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss.