A Review Of The Systematics Of Angel Sharks Emphasizing The Eastern Pacific Region

Members of the monofamilial shark order Squatiniformes, commonly known as angel sharks, sand devils, ange de mer, and angelotes, are primarily benthic dwelling sharks found mainly in temperate and sub-tropical parts of the Atlantic and Pacific Oceans. Squatiniformes are very easily distinguished from other shark-like fishes, but the individual species within the order are much more difficult to distinguish from each other. In the North Eastern Pacific (NEP) region, three separate species descriptions were published from 1859 to 1913. Since the latter date, the systematics of the entire order of Squatiniformes has been in a state of flux, from having only one description recognized as valid to having all three being recognized as valid at different points in history.  Currently only two descriptions are considered valid Squatina californica, Ayers, 1859 and Squatina armata (Philippi, 1887). Herein, the presence of at least four phenotypic morphs in the NEP is confirmed and a revised dichotomous key for the region is presented.