Acanthonyx is a genus of crabs, in the family Epialtidae. Species so far known include: * Acanthonyx consobrinus A. Milne-Edwards, 1862 * Acanthonyx dentatus H. Milne-Edwards, 1834 * Acanthonyx depressifrons Manning & Holthuis, 1981 * Acanthonyx dissimulatus Coelho, 1993 * Acanthonyx elongatus Miers, 1877 * Acanthonyx euryseroche Griffin & Tranter, 1986 * Acanthonyx formosa Wu, Yu & Ng, 1999 * Acanthonyx inglei Tirmizi & Kazmi, 1988 * Acanthonyx limbatus A. Milne-Edwards, 1862 * Acanthonyx lunulatus (Risso, 1816) * Acanthonyx minor Manning & Holthuis, 1981 * ?Acanthonyx nodulosa (Dana, 1852) * Acanthonyx petiverii H. Milne-Edwards, 1834 * Acanthonyx quadridentatus Krauss, 1843 * Acanthonyx sanctaehelenae Chace, 1966 * Acanthonyx scutellatus MacLeay, 1838 *