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