Gastroptychus is a genus of squat lobsters in the family Chirostylidae, containing the following species: * Gastroptychus affinis (Chace, 1942) * Gastroptychus brachyterus Baba, 2005 * Gastroptychus brevipropodus Baba, 1991 * Gastroptychus cavimurus Baba, 1977 * Gastroptychus defensus (Benedict, 1902) * Gastroptychus formosus (Filhol, 1884) * Gastroptychus hawaiiensis Baba, 1977 * Gastroptychus hendersoni (Alcock & Anderson, 1899) * Gastroptychus iaspis Baba & Haig, 1990 * Gastroptychus investigatoris (Alcock & Anderson, 1899) * Gastroptychus laevis (Henderson, 1885) * Gastroptychus meridionalis de Melo-Filho & de Melo, 2004 * Gastroptychus milneedwardsi (Henderson, 1885). * Gastroptychus novaezelandiae Baba, 1974 * Gastroptychus paucispina Baba, 1991 * Gast