Habitat and Ecology
Syngnathoides biaculeatus is generally found in seagrass beds or algal flats in the protected shallow waters of lagoons and bays, its colouring matching plants well (Randall et al. 1997). Adults are found in large Sargassum rafts (Kuiter 1996) and juveniles are occasionally found among debris floating offshore (
Behaviour and Biology
Syngnathoides biaculeatus has a breeding season of between October and April in
Syngnathoides biaculeatus is a poor swimmer, propelling itself by the winnowing action of the dorsal and pectoral fins (Pogonoski et al. 2002). Some individuals have been observed near the surface of the water or jumping out of the water entirely (Dawson 1986, Kuiter 1996). Prey items include shrimps, fish, and amphipods (Nakamura et al. 2003) as well as other tiny crustaceans (Allen and Swainston 1992).
Syngnathoides biaculeatus has been reported to achieve a maximum length of between 260 to 300 mm (Kuiter 1996, Takahashi et al. 2003) and displays significant size dimorphism, with males growing bigger than females (Takahashi et al. 2003). Although growth of S. biaculeatus has been reported as rapid over a life span of less than two years (Takahashi et al. 2003), more recent studies suggest that growth rates are slower and life spans can reach three years (Barrows et al. unpub data).