Argulus
Argulus is a genus of small crustacean ectoparasites known as fish lice. They belong to the class Branchiura, within the phylum Arthropoda. Argulus species are external parasites that infest a wide range of freshwater and some marine fishes worldwide. Notable species include Argulus foliaceus (the common fish louse) and Argulus japonicus (the Japanese fish louse).
Biology and life cycle: Argulus attaches to the skin, scales, fins, or gills of hosts using suction
Impact and diagnosis: Infestations cause visible irritation, rubbing, flashing, and lethargy; heavy infestations can lead to
Management: Quarantine of new fish, thorough cleaning of equipment and tanks, and treatment with approved parasiticides