Species: Syngnathus pelagicus, Sargassum pipefish

Syngnathus pelagicus Linnaeus, 1758

Sargassum pipefish

Snout long [56 (42-63)% of head length] and slender (depth 9-29% of length); a narrow bar of bone in front of eye; no ridge above operculum, or along side of snout; ridges along top of snout and head low; opercular ridge, only on front 1/3 of opercle in adults; body and front part of tail long and slender; dorsal fin 25-34, fin origin on trunk, well before anus; anal fin 2-4; pectoral fin 12-16; no pelvic fins; tail fin 10; main body ridges low, edges granular or finely toothed, barely indented at ring margins; ridge along side of body ends under dorsal fin, not joining that along side of tail; upper ridge of body discontinuous with that of tail just behind dorsal fin; ridges along bottom of body and tail joined; trunk rings 15-18; tail rings 30-34; no skin flaps; brood pouch under tail, its plates folded inwards.