26 species (see text) Ceratothoa is a genus of isopod ectoparasites of teleost fish,[2][3] first described by James Dwight Dana in 1852.

[1] Infection by Ceratothoa can cause anaemia, lesions, growth retardation, emaciation, and mortality in their fish hosts.

[3] Currently, 26 valid species in this genus are recognized:[1] C. carinata and C. oxyrrhynchaena were redescribed in 2013,[5] and C. angulata, C. capri, C. carinata, C. collaris, C. gilberti, C. gobii, C. guttata, C. italica, C. oestroides, and C. verrucosa in 2016.

[6] A number of taxa are species inquirendae:[1]

This isopod-related article is a stub.