cayennensis, Syngnathus Sauvage [H.-E.] 1882:176 [Bulletin de la Société philomathique de Paris (7th Série) v. 6; ref. 3894] Cayenne, French Guiana. Holotype (unique): MNHN A-4247. Type catalog: Bertin & Estève 1950:43-44 [ref. 19576]. •Synonym of Oostethus brachyurus (Bleeker 1853), subspecies lineatus (Kaup 1856) -- (Dawson 1979:476 [ref. 19285], Dawson 1982:17 [ref. 6764]). •Synonym of Microphus brachyurus (Bleeker 1853) -- (authors). •Synonym of Microphis lineatus (Kaup 1856) -- (Ferraris in Reis et al. 2003:591 [ref. 27061], Haÿ et al. 2023:23 [ref. 40264]). Current status: Synonym of Microphis lineatus (Kaup 1856). Syngnathidae: Nerophinae. Habitat: freshwater, brackish, marine.