Pelagic Thresher - Taxonomy and Phylogeny

Taxonomy and Phylogeny

The pelagic thresher was originally described by Japanese ichthyologist Hiroshi Nakamura on the basis of three large specimens, none of which were kept as a type specimen. He illustrated one of the three specimens in his paper, "On the two species of the thresher shark from Formosan waters", published in August 1935. Nakamura also separately illustrated and described a fetus, that Leonard Compagno later concluded was probably of a common thresher. Several authors, including Gohar and Mazhar (1964, Red Sea), Kato, Springer and Wagner (1967, Eastern Pacific), Fourmanoir and Laboute (1976, New Caledonia), Johnson (1978, Tahiti), and Faughnan (1980, Hawaiian Islands) have published illustrations of "common threshers" that were in fact pelagic threshers.

An allozyme analysis conducted by Blaise Eitner in 1995 showed that the closest relative of the pelagic thresher is the bigeye thresher (A. superciliosus), with which it forms a clade. The specific epithet pelagicus is from the Greek pelagios, meaning "of the sea". Another common name is the smalltooth thresher.