Aptocyclus De la Pylaie, 1835: 528 (type species: Cyclopterus ventricosus Pallas, 1769).
Cyclopterichthys Steindachner, 1881: 192 [type species: Cyclopterichthys glaber Steindachner, 1881 (= junior synonym of Cyclopterus ventricosus)].
Liparops Garman, 1892: 42 [type species: Cyclopterus stelleri Pallas, 1814 (= junior synonym of Cyclopterus ventricosus)].
Elephantichthys Hubbs & Schultz, 1934: 21 [type species: Elephantichthys copeianus Hubbs & Schultz, 1934 (= junior synonym of Cyclopterus ventricosus)].
Pelagocyclus Lindberg & Legeza, 1955: 436 [type species Pelagocyclus vitiazi Lindberg & Legeza, 1955 (= junior synonym of Cyclopterus ventricosus)].
Diagnosis. See “Diagnosis” of the subfamily Liparopsinae.
Remarks. Lindberg and Legeza (1955) established the genus Pelagocyclus, known only from the holotype of Pelagocyclus vitiazi Lindberg & Legeza, 1955, and were followed by many authors (e.g., Ueno, 1970; Kido, 1984; Nelson, 1994), until Kido & Shinohara (1996) demonstrated the conspecificity of P. vitiazi and A. ventricosus (Pallas, 1769), the latter having priority.
This genus includes only A. ventricosus.