title: No longer a circumtropical species: revision of the lizardfishes in the Trachinocephalus myops species complex, with description of a new species from the Marquesas Islands.
abstract: Trachinocephalus, a formerly monotypic and nearly circumtropical genus of lizardfishes, is split into three valid species. Trachinocephalus gauguini n. sp. is described from the Marquesas Islands and is distinguished from the two other species in the genus by having a shorter snout, a narrower interorbital space, larger eye and modally fewer anal-fin and pectoral-fin rays. The distribution of Trachinocephalus myops (type species) is restricted to the Atlantic Ocean and the name Trachinocephalus trachinus is resurrected for populations from the Indo-West Pacific Ocean. Principal component analyses and bivariate plots based on the morphometric data differentiated T. gauguini from the other two species, but a substantial overlap between T. myops and T. trachinus exists. Phylogenetic evidence based on mtDNA COI sequences unambiguously supports the recognition of at least three species in Trachinocephalus, revealing deep divergences between the Atlantic Ocean, Indo-West Pacific Ocean and Marquesas entities. Additional analyses of species delimitations using the generalized mixed Yule coalescent model and the Poisson tree processes model provide a more liberal assessment of species in Trachinocephalus, indicating that many more cryptic species may exist. Finally, a taxonomic key to identify the three species recognized here is provided.
authors.affiliation: Instituto de Investigaciones Marinas y Costeras INVEMAR, Calle 25 No. 2-55, Playa Salguero, Santa Marta D. T. C. H., Colombia.
authors.forename: A
authors.initials: A
authors.lastname: Polanco F
authors.affiliation: Universidad Nacional de Colombia sede Caribe, CECIMAR, El Rodadero, Santa Marta, Colombia.
authors.forename: A
authors.initials: A
authors.lastname: Acero P
authors.affiliation: University of Puerto Rico, P. O. Box 23360, 00931-3360, Río Piedras, San Juan P. R., Puerto Rico.
authors.forename: R
authors.initials: R
authors.lastname: Betancur-R
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D001699:Biometry; D004272:DNA, Mitochondrial; D005399:Fishes / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D062312:Islands; D010140:Pacific Ocean; D010802:Phylogeny; D010858:Pigmentation; D011114:Polynesia; D025341:Principal Component Analysis
chemical_list: D004272:DNA, Mitochondrial
keywords: Atlantic Ocean; Marquesas Islands; Pacific Ocean; T. gauguini; T. myops; T. trachinus