Western Smooth Boxfish
The Western Smooth Boxfish has a distinct but smoothly rounded ridge over back with numerous dark blotches. Juveniles and females pale whitish brown with fewer dark brown blotches, and are moderately common on shallow coastal reefs, particularly near seagrass beds, while large males are a pale blue colour with iridescent blue lines and are sighted less often
Boxfish and cowfish similarly have a hard-shelled carapace consisting of large, fused triangular bony plates, with holes for fins and slits for gills. Their skin lacks scales and contains toxins making them poisonous to eat. Their small lips protrude in a puckered profile that is used for blowing a jet of water over sediment to expose prey while feeding. They tend to be slow moving fish, due to the small size of their fins, though short bursts have been observed during social interactions. Western Smooth Boxfish grow to a maximum size of 39 centimetres and are found from Shark Bay, WA to the Great Australian Bight, SA.
Occurrence at the Busselton Jetty
Females are occasionally sighted from the Observatory windows, swimming over the rubble searching for small crustaceans. Sightings of males are much rarer, with observations usually being of a large male cruising in the waters just above the reef.
Image by: S. Teede