Type species. Agathotanais ingolfi Hansen, 1913
Generic remarks. Hansen (1913) erected this genus to accommodate his new species A. ingolfi from the Danish Ingolf expedition (by monotypy). Lang (1971 b) described the ‘second’ species of the genus, A. hanseni, but was apparently not aware that Kudinova-Pasternak (1970) already had described A. spendidus from the Kurile-Kamchatka Trench. Later several additional species were described, primarily from the Indo-Pacific region (Kudinova-Pasternak 1989, 1990; Larsen 1999 b).
Agathotanais is a cosmopolitan genus to be found in any deep-water samples around the world (Bird & Holdich 1988; Larsen 1999 a, b). The most recent key to the genus is given by Larsen (1999 b).