Morphologic analysis and Neotype designation of the Raspthorn sandskate, Psammobatis scobina, from its type locality

FUENTES, PAMELA; MABRAGAÑA EZEQUIEL; CONCHA, FRANCISCO

REVISTA DE BIOLOGIA MARINA Y OCEANOGRAFIA

INST OCEANOLOGIA

Lugar: Valparaíso; Año: 2021

0717-3326

The genus Psammobatis is endemic to South America, and three of its species are sympatric along the Chilean coast. Its morphological similarity together with the absence of type material have given evidence that the taxonomic identification of P. scobina is especially complex. Theaim of this work was to allow for objective identification and comparisons of P. scobina, providing a new morphological characterization, incorporating both morphometric and meristic features for both sexes, and designating a Neotype. Morphometric and meristic data are presented separately for the Neotype, and for males and females to determine variability between sexes. Although there is overlap between some morphometric features of males and females, there are also some morphometric measures that differed between sexes among specimens of similar sizes, such as disc width, length of posterior pelvic lobe, preoral length, distance between fifth gill slits and distance from cloaca to second dorsal fin. Additionally, with the Principal Component Analysis (PCA) and Cluster analyses it was possible to identify sexual dimorphism in the specimens, with the most influential variables related to tail length. There are several unresolved issues regarding the taxonomy of this problematic genus, especially those regarding P. scobina and P. normani, which are sympatric in the southeastern Pacific. In addition to the analysis of skeletal structures and egg cases, an integrative comparative morphometric analysis, based on a recent standardized methodology with the inclusion of both morphological and molecular data, is still needed. The designation of a Neotype for objective comparative purposes, will allow such future study.