Bathylagoides wesethi very low on the underside of the body. The colour is dark brown above with black spots and a black patch around the operculum, which extends halfway up the body. The flanks are silvery-grey and the fins lack pigment. The caudal peduncle is narrow, the caudal fin is short, and the lateral line, which is high on the body, extends into the tail fin. The maximum length to which this fish grows is about . The snubnose blacksmelt is found in deep water in the Pacific Ocean off the western coast of North America. Its range extends from 45°N to
Caudal cell mass dysraphisms. These types of abnormalities arise from specific structures formed in the caudal mass, for example if proper differentiation of the caudal mass doesn't occur, it could result in a type of spinal dysraphism. One example of spinal dysraphism is caudal regression syndrome. Patients suffering from caudal regression syndrome can experience a varying degree of the abnormality ranging from partial lack of the tail bone and pelvis to more significant cases where there may be paralysis and, as a result, inhibited function in the bowel and bladder. This abnormality can be caused by the caudal cell mass not developing properly