Author: Capello, 1868
Remarks:
Two species of Pseudotriakis are commonly recognized, the Atlantic P. microdon Capello, 1867 and the Pacific P. acrales Jordan and Snyder, 1904. Elsewhere, the writer has traced the taxonomic history of Pseudotriakis (Compagno, 1979), and noted that several writers have disagreed on the validity of P. acrales. The writer has compared the holotype of P. acrawes (Stanford University, SU 12903, 1765 mm immature male, from Suruga Gulf, Japan) with various literature accounts of the two species as well as with specimens of Pseudotriakis from the North Sea and from the Hawaiian Islands. This resulted in the writer being unable to find any reliable characters to separate Atlantic and Pacific Pseudotriakis, although it was initially thought that the Atlantic species might have a longer snout. The criteria that Jordan and Snyder (1904) and Bigelow and Schroeder (1948) proposed to separate these species do not hold, and hence, they are tentatively synonymized here.