The difference between Silurus meridionalis and Silurus meridionalis is that the adult Silurus meridionalis is bigger, and most of the Silurus meridionalis in China lives in the south, and Silurus meridionalis is common in the north (Heilongjiang Province).

Silurus soldatovi meridionalis? Chen, a fish belonging to Silurus, Silurus and Silurus. Local names: six-beard catfish, river catfish, fork catfish, catfish Balang, big mouth catfish, big catfish mackerel and so on. The shape is similar to that of catfish, and the difference between them is that the end of the mouth crack of catfish reaches or exceeds the lower part of the eye. The maxilla must reach the base of pectoral fin. There are 2 ~ 3 rows of granular protrusions at the front edge of pectoral fin thorn. The caudal fin is asymmetrical, and the upper leaf is longer than the lower leaf.

The catfish is similar in size to the common catfish, with a wide front, a flat back, a large and round abdomen. The back is mostly light yellow or grayish brown, with golden lateral lines on both sides of the body and irregular dark spots, and the abdomen is white. The body surface is smooth and scaleless, and there is a mucus hole at the base of pectoral fin, which can secrete a lot of mucus when stimulated. The head is flat and wide, the eyes are small, the mouth is large, and the upper and lower jaws have sharp teeth. There are three pairs of whiskers, maxillary whiskers 1 pair, and they are longer than the head length; There are 2 pairs of mandibular whiskers, which are short and easy to break. The dorsal fin is smaller. The pectoral fin has a hard thorn, and there are many tumor-like protrusions on the edge of the hard thorn, and there is no saw-like notch on the edge. The anal fin is long, from the back of the anus to the base of the caudal fin. The external morphological characteristics of Silurus asotus are shown in the figure.