Harlequin Fish

The harlequin fish is a diurnal forager that has a long life-cycle, a small home range and strong site fidelity. It is likely to be harmed by localized anthropogenic changes and by recreational fishing, though their fishing along the coast is low.

The harlequin fish is native to the temperate waters, and is found over the shallow rocky reefs and in caves located in the cool coast of South-Western Australian waters. It's believed that this reef-dwelling species has an important place in the ecology of its environment since it is a top predator, and is relatively common in the area.

Harlequin fish can live up 42 years, and can grow a maximum length of 75 cm (30 in). In the otoliths of O. dentex, a single opaque zone forms annually, and age of the individual can be determined by the number of these zones. Considering their long life at the young age of 4-5, both the females and males, grow rapidly, with the males showing slight change in color as they reach maturity. Before maturing, the early juveniles are thought to be residing in the crannies and deeper in the caves, which would protect them against predatory piscivorous fish species that exist nearby. As the juvenile individuals approach their mature size, they start moving around the reef. Typically, the male individuals are solitary, and come together with females during spawning season.

Sexual reproduction. The harlequin fish is gonochoristic, it has indeterminate fecundity. This species also exhibits batch spawning which corresponds with the individuals being widely dispersed and scarce. It's unknown whether juveniles present bisexuality early in life, but if bisexuality is present, it's assumed that, some time before the individual reaches maturity, it disappears early in gonadal development. O. dentex have small testes, which implies low sperm competition. The spawning season for O. dentex is through September to March, and it peaks during the period between November and January. …