Chinese trumpetfish in shape to the anal fin which is just under. The pelvic fins are located in the middle of the body and are small, with one basal black spot. The body coloration can be uniform or mottled in a range of grey, brown, or dark green. Some fish are uniformly bright yellow. The rear part of the body is normally black with white dots. Two black spots are present on the tail. The compound set of the long caudal peduncle and the caudal fin is yellowish, whatever the fish coloration. Caudal fin usually has two round black spots, at least
Synodontis filamentosus attached to flexible, stalk-like structures and described as "s-shaped" or "hooked". The number of teeth on the mandible is used to differentiate between species; in "S. filamentosus", there are about 20 teeth on the mandible. The color of the fish is greyish, with small, scattered dark spots, and whitish on the underside. The dorsal and caudal fins have small greyish spots. The lower borders of the caudal fin are black. The maximum standard length of the species is . Generally, females in the genus "Synodontis" tend to be slightly larger than males of the same age. In the wild, the