Chitons (Mollusca, Polyplacophora) from Sao Tome and Principe Islands

The chiton fauna of Sao Tome and Principe Islands is poorly known and here we present the first comprehensive and illustrated account of living Polyplacophora from these islands. Four species have been reported to date: Lepidochitona rolani Kaas & Strack, 1986, Chiton lyratus Sowerby, 1840, Chiton canariensis d'Orbigny, 1839 and Notoplax productus (Carpenter in Pilsbry, 1892). Two of these species are actually valid, while C. lyratus is considered a synonym of Rhyssoplax canariensis. N. productus was incorrectly considered to be the valid name for Craspedochiton foresti (Leloup, 1965). The present paper increases the list of living chiton species to 12, of which two are described as new, namely Stenoplax hernandezi sp. n. and Callochiton saotomensis sp. n. Three species are assigned only at generic level but reflect new records for these islands. Type specimens of Chiton lyratus and Chiton canariensis are figured.