Comprehensive DescriptionRead full entry
Typhlonectes compressicauda can reach 523 mm in total length (Taylor 1968). The posterior part of the body is compressed, with a keel (Taylor 1968). 81-86 primary annuli are present but secondary annuli are lacking (Taylor 1968). Dermal scales are present (Wake 1975). The skull is zygokrotaphic (Nussbaum 1983). The head is relatively thick and wide (Taylor 1968). There are four rows of teeth (Taylor 1968), which are curved and have broadly dilated crowns rather than pointed tips (Wilkinson 1991; Hraoui-Bloquet and Exbrayat 1996). The tongue has two large narial plugs (Taylor 1968). Tentacles are located directly behind the nasal orifices (Jared et al. 1999). Narial apertures are subtriangular (Wilkinson 1989). Eyes are covered by thin skin in juveniles and thick, nonglandular skin in adults (Wake 1985). Fritzsch and Wake (1986) showed that ampullary organs are present on the head, most densely on the snout, and presumably used for electroreception; the original paper (Fritzsch and Wake 1986) examined a larval specimen of T. compressicauda, and an adult specimen of what was thought to be T. compressicauda, concluding that this species retained ampullary organs into adulthood, but a later paper (Dünker et al. 2000) refers the adult specimen to the closely related T. natans. (See Comments section below for more on taxonomy.)
Larvae look like miniature adults, though they possess lateral lines (Jared et al. 1999) and broad leaf-like gills (Taylor 1968). Gills are attached dorsally and fused at the bases (Wilkinson 1989). Within 24-48 hours after birth, the gills fall off (Exbrayat and Delsol 1985). Ampullary organs are present on the larval head (Fritzsch and Wake 1986) and may be retained into adulthood, since adults of the related species T. natans have ampullary organs (see paragraph above).
Described by Duméril and Bibron (1841). Typhlonectes compressicauda has a diploid karyotype of n=28 (Wake et al. 1980). This species has frequently been confused with T. natans in the literature (M. H. Wake, pers. comm.); specimens reported as T. compressicauda in the literature prior to 1994 should be regarded as most likely belonging to T. natans (R. Nussbaum, pers. comm., cited in Smits and Flanagin 1994). More extensive taxonomic review is required (IUCN 2008).