polyacanthus, Syngnathus Bleeker [P.] 1856:77 [Acta Societatis Regiae Scientiarum Indo-Neêrlandicae v. 1 (6); ref. 352] Manado, Sulawesi, Indonesia. Syntypes: RMNH 7246 (2). Bleeker specimens: BMNH 1867.11.28.359 (1). •Synonym of Oostethus brachyurus (Bleeker 1854) -- (Dawson 1979:467 [ref. 19285], Kottelat 2013:306 [ref. 32989]). •Synonym of Microphis brachyurus (Bleeker 1854) -- (Dawson 1984:152 [ref. 5879], Dawson 1985:138 [ref. 6541], Kuiter 2009:276 [ref. 30404], Haÿ et al. 2023:23 [ref. 40264]). Current status: Synonym of Microphis brachyurus (Bleeker 1854). Syngnathidae: Nerophinae. Habitat: freshwater, brackish, marine.