Tortanus scaphus and Tortanus lophus, New Pacific Planktonic Copepods, with Notes on Tortanus murrayi (Calanoida, Tortanidae)

Abstract

The calanoid genus Tortanus contains 17 known species of predaceous copepods which inhabit coastal waters of the world, except the Antarctic, eastern North Atlantic, and Mediterranean. All except T. vermimlus Shen (1955) and T. denticulatus Shen & Lee (1963) are listed in Jones and Park (1968). Two schemes have been proposed to subdivide the genus Tortanus. Steuer (1926) divided the eight species then known into three groups, without giving names to the groups. Sewell (1932) assigned the seven Indian Ocean species to two subgenera, Tortanus and Atortus. Sewell's subgenera correspond exactly to two of Steuer's groups, but Sewell made no mention of Steuer's classification, even though he listed Steuer's revision in his bibliography (Sewell, 1929).