fish louse

noun

Definition of fish louse

: any of various small crustaceans (as the carp louse) parasitic on fishes especially : any of various true copepods that are found on the skin or gills or in the mouth of fishes and that exhibit varying degrees of degeneration in the adult state due to their parasitic habits — see lernaea

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“Fish louse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fish%20louse. Accessed 1 Apr. 2020.

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