Blackspot Sergeant

Abudefduf sordidus, more commonly known as the blackspot sergeant or kūpīpī in Hawaii (🇺🇸 United States), is a fascinating species of damselfish that inhabits the tropical Indo-Pacific region. Part of the Pomacentridae family, these fish are notable for their striking appearance and interesting behavioral traits.

Characterized by their yellowish-grey color adorned with six broad brown bars and several narrow light bars, blackspot sergeants have a distinct black spot located at the upper base of their tail. They can grow to impressive lengths of up to 24 cm (9.4 inches) and live up to nine years in their natural habitats. These vibrant fish are typically found in tidepools and shallow rocky areas where there is moderate water movement at depths from 1 to 3 meters (3 to 10 feet).

Juvenile blackspot sergeants inhabit tidepools, feeding on a varied diet of algae, small animals, and plankton. As they mature, these fish transition to deeper waters where conditions provide more surge, indicating a shift in habitat preference as they grow. Known for their territorial nature, blackspot sergeants exhibit aggressive behavior towards other fish, especially in confined spaces like tidepools.

During the daytime, these fish are usually observed near rocky areas, taking refuge under various structures at night for protection. This nocturnal behavior highlights their adaptability to the changing environment over a 24-hour period. Blackspot sergeants are oviparous, meaning they lay eggs. Males are responsible for constructing nest sites in rocky areas to entice females during the breeding season, a period marked by heightened aggression as part of their mating rituals.

In summary, the blackspot sergeant is a solitary yet fascinating creature, whose vibrant appearance and aggressive territoriality make it a distinctive inhabitant of the tropical Indo-Pacific waters. Its lifecycle from a juvenile in tidepools to an adult in more challenging environments showcases its adaptability and survival strategies in the wild.