Grimpoteuthis are in the family Opisthoteuthidae (umbrella octopuses)external link and have short, squat, semi-gelatinous bodies with an internal U or V-shaped cartilaginous shell. They lack the secondary web (the web which extends from each arm to the primary web) and longer cirri found in the family Cirroteuthidaeexternal link and their eyes are much more developed. They can grow up to about 20external link cm in length. Species in the Opisthoteuthidae family have suckers without tooth-like structures. Their radula (a chitinousexternal link, ribbon-like band in the mouth of cephalopods that contains up to seven transverse rows of teeth that aid in the break up and transport of food into their esophagus for swallowing) in Opisthoteuthidae tends to be reduced or completely absent, as most species swallow their prey whole.