Do fishes release nitrites?

Nitrites:

1. Nitrites are chemical substances that are either salts or esters of nitrous acid.
2. Nitrite is also dangerous to fish and is converted to nitrate once again by helpful nitrifying bacteria.
3. Nitrites are toxic to all fishes.
4. Fishes do not release nitrites.
5. Many fishes and invertebrates expel waste in the form of ammonia.

No, fishes do not release nitrites.