Harlequin fish

While it may look like a tropical fish species, the harlequin fish is a colourful, rocky reef species endemic to the Great Southern Reef. Affectionately known as “Harlies”, these beautifully vibrant fish like to live on high profile reefs, in caves and crevices in clear coastal waters. They are known to have high site fidelity (staying close to home) and are usually found resting along the seabed amidst short bursts of swimming. Their colour can vary greatly, ranging from orange, to pink, red, green or brown with large spots and dashes that can be yellow, green or even a brilliant blue as they reach adulthood. These spots change in colour and size as they reach maturity, which is also the only way to differentiate the males and the females. Researchers found that in the younger individuals, these spots are yellow and when males reach sexual maturity they turn blue. During the spawning season, the colour blotches in the males intensify, playing a role in courtship. A classic daytime ambush predator, the harlequin has two eyes on the top of its head that operate independently to one another which allows them to set up a hunting spot and wait, very still, until a leather jacket or a small wrasse swims past as an easy target. They have enormous canine teeth in their large mouths located at the front of their jaws. Exclusively feeding on fish, they choose their prey based on size rather than species.