Hydrophis schistosus (Daudin, 1803) — Native; Indeterminate. Hydrophis schistosus Daudin, 1803f: 386–387. Holotype: BMNH 1946.1.10.7 (formerly RCSM & BMNH 1921.7.28.1), by original designation. Type locality: “Bengale” (= Bangladesh and India); later restricted to “Tranquebar” (= Tharangambadi), India, by Smith (1926: 39). Beaked Sea Snake (Figures 22F & 22G) Singapore records. Hydrus schistosus — Cantor, 1847c: 1057. Enhydrina velakadien — Flower, 1899: 688. Enhydrina valakadyn —Stejneger, 1907: 438.— de Rooij, 1917: 221.—Sworder, 1923: 70. Enhydrina valakadien — Boulenger, 1912: 194. Enhydrina schistosa — de Haas, 1950: 590.— Horwood, 1968: 34.—Sharma, 1973: 237.— Gremli, 1988: 60.—F.L.K. Lim & M.T.-M. Lee, 1989: 115.—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim & F.L.K. Lim, 1992: 148.—L.M. Chou et al., 1994: 105.— Cox et al., 1998: 35.— Iskandar & Colijn, 2001: 131.—K.P. Lim & F.L.K. Lim, 2002: 148.— Das, 2010: 318.— Das, 2012a: 93.— Wallach et al., 2014: 269.—Chan-ard et al., 2015: 313.— Das, 2018: 115. “ Enhydrina ” —P.K.L. Ng et al., 2011: 302. Hydrophis (Enhydrina) schistosus — Leviton et al., 2018: 466. Hydrophis schistosus — Charlton, 2020: 74. Remarks. Voris and Jeffries collected the only specimen of H. schistosus from Singapore from a kelong at LCK on 28 July 1981 (Fig. 22F). This specimen was deposited at the Raffles Museum and is catalogued under ZRC.2.2047. Cantor (1847c) was the first to report H. schistosus from Singapore, and in his account of the species he stated that it was the most abundant sea snake in Singapore, as did Horwood (1968). Sharma (1973) and Gremli (1988c) also both declared that H. schistosus was common in Singapore, and Shelford (1916) recounted H. schistosus as one of the most common sea snakes in the South China Sea between Singapore and Sarawak, Malaysia, and Borneo. However, neither of these authors provided any evidence. Thus, it appears that H. schistosus may be common in the waters surrounding Singapore, but the Voris and Jeffries specimen is the only record from Singapore. Occurrence. Known from one specimen from LCK in 1981. Rare. Singapore conservation status. Not Evaluated. Conservation priority. Highest. IUCN conservation status. Least Concern [2018]. LKCNHM & NHMUK Museum specimens. Lim Chu Kang: ZRC.2.2047 (28-Jul-1981). Additional Singapore museum specimens. No specimens. Singapore localities. Lim Chu Kang.

Published as part of Figueroa, Alex, Low, Martyn E. Y. & Lim, Kelvin K. P., 2023, Singapore's herpetofauna: updated and annotated checklist, history, conservation, and distribution, pp. 1-378 in Zootaxa 5287 (1) on pages 196-197, DOI: 10.11646/zootaxa.5287.1.1, http://zenodo.org/record/7960319