A small reef shark with a large dark spot behind the gills that walks on its fins across reef flats, and can survive several hours in water with almost no oxygen.
To about 1 m, pale brown with dark spots and a single large black spot ringed in white behind each pectoral fin — the epaulette. It is a slender, small-headed shark with the tail nearly as long as the rest of the body.
It walks. The paired fins are used as legs and the animal crosses reef flats and even moves between tide pools out of the water. Two things go with that: it survives water with almost no oxygen for hours by shutting down parts of its brain and reducing its heart rate, and it tolerates being briefly out of it. It is nocturnal, hunting worms, crabs and small fish in the shallowest water on the Great Barrier Reef, and it is normally found by a torch on a shallow night dive.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.