What is the meaning of Fish_louse?

Any aquatic crustacean which is a parasite of fish, typically attached to the skin or gills

  1. Certain members of class Copepoda.
  2. Synonym of carp louse (family Argulidae)

Certain members of class Copepoda.

Synonym of carp louse (family Argulidae)

Source: wiktionary.org