Review of the genus Sagittalia Boyer, 2024 in the Indo-Pacific Province, with the description of ten new species

The fauna from Indo-Pacific waters attributed to the cystiscid genus Sagittalia Boyer, 2024 is reviewed. Eight species are revised in this genus: Marginella pulchella Kiener, 1834 recognized from Norfolk Island; M. deburghi A. Adams, 1864 described from West Australia; M. pacifica Pease, 1868 described from the Tuamotu Island; M. shepstonensis E.A. Smith, 1906 described from South Africa; M. fulgurata Hedley, 1911 described from West Australia; M. albomaculata May, 1911 described from Tasmania; M. newmanae Cotton, 1949 described from Esperance (southwest Australia); Gibberula squamosa Boyer, 2003 described from New Caledonia. Ten Indo-Pacific species are described as new in the genus Sagittalia: S. ovata n. sp. Boyer et Rosado from South Africa and Mozambique; S. granum n. sp. Boyer et Rosado from Mauritius; S. hervillardi n. sp. from Djibouti; S. cingalica n. sp. Boyer et Gori from Sri Lanka; S. similis n. sp. Boyer et Rosado from Sri Lanka; S. nancyae n. sp. from west and south Australia; S. marshalli n. sp. Boyer et Renda from southwest Australia; S. kieneriana n. sp. from the southern half-part of Australia; S. thorae n. sp. from the Queensland; S. coralensis n. sp. Boyer et Raines from the Coral Sea Islands Territory. Several species attributed to Sagittalia are tackled and compared in the frame of this review, but not formally revised, either because they were fully revised in previous works, or because nothing useful can be added for now to the previous reports, or because of insufficient documentation at hand. Live specimens and their soft parts are pictured and described for three of the new species. Possible species groups are proposed. Oman is sheltering the higher Sagittalia diversity documented until now, what is attributed to important remains of the Tethyan fauna in this area. Similar diversity might occur in the Gulf of Aden and off the coasts of East Africa, which remain about unexplored areas as far as marine micro-gastropods are concerned. The somewhat important Sagittalia diversity documented from Australia might prove to be much higher if fitting collecting effort were applied.