Telatrygon Last, Naylor & Manjaji-Matsumoto, 2016, gen. nov.
Creators: name: Last, Peter R.
name: Naylor, Gavin J. P.
name: Manjaji-Matsumoto, B. Mabel
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Myliobatiformes
Potamotrygonidae
Telatrygon

description: Genus Telatrygon gen. nov.
Type species Trygon zugei Müller & Henle, 1841; newly proposed.
Definition. Small to medium-sized dasyatids (adults typically to 29–73 cm DW) characterised by the following: strongly depressed, weakly rhombic to rhombic disc with pectoral-fin apex narrowly angular to broadly rounded; snout acutely angular and elongate (2.9–4+ times combined orbit and spiracle length); eye small to very small and sunken; nasal curtain typically narrowly skirt-shaped; mouth narrow and lacking oral papillae; tail rather long and filamentous distally (length 1.4–3 times DW), its base narrow to medium width; pelvic fins medium-sized, protruding slightly beyond disc; dorsal fold variably developed, from prominent to absent; ventral fold low with a short to long base; caudal sting close to tail base (distance from pectoral-fin insertion to caudal-sting base 2–2.5 times interspiracular width); skin smooth; no scapular thorns or denticle band; median thorns on nape in a row, usually separated from larger thorn-like denticles on tail; no other thorns or rarely denticles on tail; dorsal coloration plain; ventral surface white, disc margin usually dark edged; tail plain or darker dorsally than ventrally; marine, Northern Indian Ocean and Western Pacific.
Etymology. Combination of the Latin telum (javelin, spear, arrow, dart) and Greek trygon (stingray) with reference to the long, narrowly pointed snout possessed by all members of the genus.
Species. T. acutirostra (Nishida & Nakaya, 1988), T. crozieri (Blyth, 1860), T. zugei (Müller & Henle, 1841), and an undescribed species.
Remarks. Newly erected, morphologically conservative genus whose members were formerly assigned to Dasyatis. Telatrygon acutirostra resembles other species of Telatrygon in disc shape (apart from having a much longer snout and tail, smaller eyes, and less well-developed skin folds on the tail). It is otherwise similar in the states of most external characters used to define the dasyatid genera. However, based on phylogenetic analysis of NADH2 sequences (and unpublished analyses of whole mitochondrial genomes), T. acutirostra does not cluster with other species of Telatrygon (Fig. 1), so its placement in the group is provisional pending more detailed anatomical studies. Telatrygon is represented by an undescribed species in the Western Pacific (Last, White & Naylor, submitted), and a cognate occurring in the northern Indian Ocean (identified by molecular data, GN) appears to be conspecific with Trygon crozieri Blyth, 1860; placed in synonymy with Dasyatis (= Telatrygon) zugei by Nishida & Nakaya (1988, 1990). Although Blyth’s description is brief, his species is undoubtedly a Telatrygon, based on disc shape, squamation, and tail morphology. Given that no other member of this group is known from the region, we propose the resurrection of Blyth’s species as Telatrygon crozieri.
description: Published as part of Last, Peter R., Naylor, Gavin J. P. & Manjaji-Matsumoto, B. Mabel, 2016, A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights, pp. 345-368 in Zootaxa 4139 (3) on page 357, DOI: 10.11646/zootaxa.4139.3.2, http://zenodo.org/record/262765