Jansen’s Wrasse

Interesting Info

• The Jansen’s wrasse is a species of marine fish found across Australia from Western Australia, the Northern Territory and Queensland. It is also well known in other parts of the Indo-Pacific region.
• The Jansen’s wrasse can exhibit different colours and patterns depending on the region and the sex of the individual. While the species is typically described as having a greenish-blue head, yellow back, and pinkish-white underbelly, some individuals may appear black and white. Male Jansen’s wrasses also tend to be more colourful than females, with a range of hues from blue to green to yellow.
• The species was named after the Dutch zoologist Pieter Bleeker’s friend, E. Jansen, who was an officer in the Dutch East Indies army.
• The fish feeds on a variety of small invertebrates and crustaceans, including crabs, shrimps, and small snails.
• The species is hermaphroditic, with females changing to males when the dominant male in a group dies.
• During breeding season, which typically occurs during the warmer months of the year, males establish territories and engage in courtship displays to attract females. Once a pair has formed, the female will lay eggs in a nest that the male has prepared. The male will then fertilise the eggs and guard the nest until the eggs hatch.
• The estimated lifespan is between 5 – 8 years in the wild.