The reasons why scavenger fish can't be eaten include: low nutritional value, more bacteria, bad taste, very little meat, too dirty, etc.

1, nutritional value is not high

Scavengers to garbage for food, so the nutritional value is limited, may be compared with the ordinary food fish are a big difference.

2, more bacteria

Since scavengers often swallow the feces of other fish, the garbage in the riverbed, and various kinds of algae, so they have more bacteria inside their bodies.

3, bad taste

Because the scavenger fish live underwater all year round, so they have a very heavy earthy odor.

4, meat is very little

Scavengers are exoskeleton fish, its bones are relatively large and more, but the meat is very little.

5, too dirty

Because the scavenger swallowed the feces of other fish, so people think it is very dirty, unhygienic, so by the "food" people "abandoned".