Alexander's Damsel

Pomacentrus alexanderae

Alexander's Damsel is a small reef-associated fish found in the tropical waters of the Western Pacific, ranging from the Indo-Malayan Archipelago to Taiwan and the Ryukyu Islands. It typically inhabits lagoon, inshore, and offshore reefs at depths of 5 to 60 meters, although most are found shallower than 50 meters. This species reaches a maximum length of 9.0 cm and is characterized by a compressed body with 13 dorsal spines and 14 to 15 dorsal soft rays. This damsel is usually seen swimming solitarily above the substrate, feeding on a diet that includes algae, barnacle nauplii, copepods, fish eggs, and small gastropods. During breeding, they exhibit distinct pairing, with males taking on the responsibility of guarding and aerating the demersal eggs that adhere to the substrate. For divers, encountering Alexander's Damsel can be a solitary experience as these fish are often seen alone, actively swimming above the reef. They are not known to pose any threat to humans. As of the latest assessment, the species is listed as Least Concern on the IUCN Red List.