About Pomacentrus amboinensis Bleeker, 1868
Pomacentrus amboinensis is a species of damselfish native to the Western Pacific Ocean. This species occasionally enters the aquarium trade, and grows to a maximum length of 9 centimeters. It lives in small groups made up of one mature male and several females; the mature male guards a nest site on the seafloor. After settling into a group, females rarely migrate, and new juveniles are usually able to join groups easily. As individuals reach sexual maturity, they typically lose the "eyespot" marking on their dorsal fin. Pomacentrus amboinensis is a protogynous species: all individuals begin life as females, and can later transition into males. Some males retain a juvenile-like appearance, most likely to allow them to sneak into the harems of dominant males. Behavioural experiments that controlled for brightness have confirmed that this species has colour vision, and this is apparently the first recorded example of colour discrimination in reef fish.
