Northernmost record of the Chilean torpedo Tetronarce tremens from tropical coastal waters of the Mexican Pacific

Abstract

The Chilean torpedo Tetronarce tremens is recorded for the first time in the Mexican Pacific. A single male specimen was captured by artisanal fishermen using a bottom-set gillnet off San Agustinillo, Oaxaca. The specimen identification was based on morphology and confirmed by DNA barcoding of the cytochrome oxidase subunit I gene and its comparison with sequences available in online repositories. A phylogenetic analysis of Tetronarce resulted in the clustering of three species that inhabit the Pacific Ocean: Tetronarce tremens, Tetronarce californica and Tetronarce tokionis. This study provides the northernmost record of Tetronarce tremens in the Eastern Pacific Ocean, an atypical sighting beyond its native distribution range in tropical and temperate waters off South America.