Image from An Image-Based Key To The Zooplankton Of North America.

Crustaceans of the Subclass Branchiura, or fishlice, are distinctive ectoparasites of marine and freshwater fishes. There are more than 120 freshwater species (1 family), only 18 species (1 genus) occurs in in-land habitats in North America (Poly, 2008).

Branchiurans are generally in the mm-cm size range. A carapace covers the entire cephalothorax, bearing appendages adapted for a parasitic lifestyle. The 1st and 2nd antennae as well as the maxillules are used for attachment to their host, and the mandibles are piercing organs. There are four pairs of biramous swimming legs, and the abdomen is reduced. Branchiurans have compound eyes.

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Bibliography

• Covich, A.P., J.H. Thorp & D.C. Rogers. 2010. Introduction to the Subphylum Crustacea. [in] J.H. Thorp & A.P. Covich (eds.). Ecology and Classification of North American Freshwater Invertebrates, 3rd edition: 695-723.
• Poly, W.J. 2008. Global diversity of fishlice (Crustacea: Branchiura: Argulidae) in freshwater. Hydrobiologia 595: 209-212. [Available online]
• Smith, D.G. 2001. Branchiura (fish lice). Pennak's Freshwater Invertebrates of the United States, 4th edition: 519-520.
• Cressey, R.F. 1972. The genus Argulus (Crustacea: Branchiura) of the United States. U.S. Environmental Protection Agency, Biota of Freshwater Ecosystems Identification Manual 2. 14 pp. [Available online]
• Wilson, M.S. 1959. Branchiura and Parasitic Copepoda. [in] W.T. Edmondson (ed.). Ward & Whipple Fresh-Water Biology, 2nd edition: 862-868.

Student Essays

• "Argulus foliaceus: a well-adapted, destructive freshwater fish louse" by Brad Gorzek (BIOL 490, Fall 2014 )

Web Pages

• Free-Living and Parasitic Copepods (including Branchiruans) of the Laurentian Great Lakes: Keys and Details on Individual Species
• Integrated Taxonomic Information System
• Tree of Life
• WikiSpecies
• Wikipedia
• World Register of Marine Species