Sandager's wrasse
Sandager's wrasse is a species of wrasse native to the southwestern Pacific Ocean ranging from Australia to New Zealand and the Kermadec Islands. This species can be found on reefs down to depths of about. It can reach a length of TL. It can also be found in the aquarium trade.
Etymology
The fish was named after Andreas Fleming Stewart Sandager, a lighthouse keeper in New Zealand who collected the first specimen. As the scientific name has sandeyeri as the specific epithet, a proposal was made in 1927 to change it to "sandageri" on the theory that the original description constituted a misspelling. However, in 2011, it was shown that "Sandager" was also spelled "Sandeyer" at that time and thus that the original spelling of the scientific name should stand.
Behavior
The wrasses live in small shoals consisting of one male and several 'attendant' females and juveniles. In the presence of the male, all juveniles will grow into females, but when the male dies or is removed from the shoal, the group's dominant female then undergoes physiological changes to convert herself into a male.
Description
The male fish has a deeper body, and differs significantly in colouration. For example, the male has very distinctive bands, whereas the female is paler in colour and only has 2 dark spots.