Argulidae
Guides
Branchiura
Branchiurans, Fish lice
Branchiura is a subclass of crustaceans within the class Ichthyostraca, comprising approximately 170 species of ectoparasitic fish lice. The group contains two extant families: Argulidae (fish lice) and Chonopeltidae, plus the extinct Cyclida. Branchiurans are obligate ectoparasites of freshwater and marine fishes, characterized by a flattened body adapted for clinging to host surfaces and specialized mouthparts for feeding on host blood, mucus, and tissues.