Argulus foliaceus is a freshwater fish ectoparasite that has
been reported throughout temperate regions of Europe, Central
Asia, and North America. It has been well studied in Europe,
especially the British Isles, where is has had major impacts on
UK sport fisheries through fish stress and mortality. (Harrison,
et al., 2006; Oktener, et al., 2007; Pasternak, et al., 2004)
Argulus foliaceus is found in warm, eutrophic, still lakes of
both fresh and brackish water. Eggs are laid in shady areas,
rather than in direct sunlight. Typically considered a shallow
water species, this louse is often observed laying eggs within
the top 1 m of the water column (although it will lay eggs in
deeper water at the end of the reproductive season). Argulus
foliaceus is an obligate parasite, requiring host availability.
This louse has a low host specificity, so it can infect a
variety of fish within its habitat. (Harrison, et al., 2006;
Pasternak, et al., 2000; Taylor, et al., 2006) On average,
Argulus foliaceus measures a total