The Bering Sea round bellied fish (Aptocyclus ventricosus) is a fish species in the family of round finned fish, belonging to the genus round bellied fish. It has suction cup shaped fins on its abdomen. Distributed in the North Pacific Ocean, it migrates from the deep sea to coastal areas in order to lay eggs, and breeds at the bottom of rocks in shallow waters deeper than 10 meters. Can be used as a food fish. The body is brownish gray in color, with dark spots on the back and gray on the abdomen. The pectoral fins are wide and have evolved into suction cups, and the skin is smooth without scales or small tumors. The dorsal fins have 8-9 soft stripes and the anal fins have 7-9 soft stripes. The body length can reach 41 centimeters, and it has a circular tail fin.