1, shape:
Cod has small scales, a cylindrical body and a dark blue gray or green gray back. It is about 120 cm long and the scales are very sharp. The front of the oil fish is relatively flat, the back of the head is curved, and the upper part is black or blue-black. Generally speaking, cod is bigger than oily fish.
2. Cross section:
The cross section of cod is larger than that of oily fish, and there will be a yellowish or reddish line in the middle of oily fish, but cod does not.
3. Touch:
Cod feels smooth, like a mucous membrane. Oil fish will be rough.
4. Taste:
Cod melts in the mouth, and the meat is very delicate and tender. However, oily fish has a meaty smell after frying in oil, which is very greasy, thick and has a bad taste.
Living environment of oil fish:
Oil fish live in mountain streams or caves with flowing water and where rivers have springs, and their food is mainly diatoms and aquatic insects larvae. It's a little longer, with a round front and a flat back. The body length is about 20 cm, and the back of the head is curved; The snout is round and blunt, and the snout extends forward to form the upper lip, and there is no dividing line between them.
A small part behind the lower lip is covered by a small horny protuberance. When the mouth is opened, the kissing skin and the inner surface of the lower lip become trumpet-shaped, and the mouth is in the middle of this trumpet. Oil fish live in mountain streams or caves with running water, and where rivers have springs.