They do not have pelvic fins and there are no scales on their body but in one species the body is covered in papillae. There are 19-25 spines and 7-17 soft rays in the dorsal fin and 5-11 spines and 3-7 soft rays in the anal fin.
They lack pelvic fins, have no scales on their body, but in one species, papillae cover their skin. There are 19-25 spines and 7-17 soft rays in the dorsal fin and 5-11 spines and 3-7 soft rays in the anal fin.