A New Guitarfish of the Genus Pseudobatos (Batoidea: Rhinobatidae) with Key to the Guitarfishes of the Gulf of California

摘要

A new guitarfish of the genus Pseudobatos is described based on 82 specimens obtained from the Gulf of California. Sixty-three morphometric measurements were taken on all specimens, and on ten specimens from each of three congeners. A principal component analysis and linear discriminant analysis were performed on these morphometric data for discrimination. The new species (similar to 685 mm TL) is most similar to Pseudobatos productus but differs in having a narrower maximum disc width (30-35% vs. 36-38% TL), shorter distance from nostril to disc margin (2.8-4.0% vs. 4.2-5.2% TL), narrower disc width at anterior orbit (12-19% vs. 20-22% TL), and a narrower tip of snout width (3% vs. 4-6% TL). The species is also less densely scaled between the orbits and has less pronounced rostral thorns than Pseudobatos productus. A key to the guitarfishes of the Gulf of California is also provided.