What is "piscicide"

n. 1 (context countable English) Any substance that is poisonous to fish 2 (context uncountable English) The killing of fish.

A piscicide is a chemical substance which is poisonous to fish. The primary use for piscicides is to eliminate a dominant species of fish in a body of water, as the first step in attempting to populate the body of water with a different fish. They are also used to combat parasitic and invasive species of fish.

Examples of piscicides include rotenone, saponins, TFM, niclosamide and Antimycin A (Fintrol).