Abudefduf sordidus
A large, solitary damselfish with a black tail spot.
Abudefduf sordidus, called the blackspot sergeant or kūpīpī in Hawaii, is a large, solitary damselfish from the Pomacentridae family. It lives in the tropical Indo-Pacific. Its body is yellowish-grey with six wide brown bars and six to seven narrow light bars, plus a black spot near the top of the tail base. It can grow to 24 cm long and live up to nine years in the wild. This fish is common in tidepools and rocky, shallow areas with moderate wave action, from the surface down to 3 meters deep. Juveniles stay in tidepools, eating algae, small animals, and plankton. As they mature and get larger, they move to deeper, more surge-prone areas. Blackspot sergeants are very territorial and aggressive, especially toward other fish in tidepools. During the day they stick near rocks, but at night they hide under objects. They are oviparous: males build nests in rocky spots to attract females, and during mating they are thought to be especially aggressive.
Quick Facts
- Genus
- Abudefduf
- Species
- sordidus
Facts from the source article.
Lore & Background
Blackspot sergeants are generally yellowish-grey in colour with six brown broad bars, six to seven narrow light bars and a black spot at the upper base of the tail. They can reach up to 24 cm (9.4 in) in total length and are known to live up to nine years in the wild. They are common in tidepools and rocky shallow areas with moderate surge at a depth of 0 to 3 m (0 to 10 ft). Juvenile blackspot sergeants are common in tidepools where they feed on algae, small animals, and plankton. Once they mature and become bigger, they are known to move towards deeper areas with more surge. Blackspot sergeants are very territorially aggressive, especially towards other fish in tidepools. During the day they are often found near rocky areas, although at night they tend to take shelter under various objects. Blackspot sergeants are oviparous and males build a nest site in rocky areas to attract females. During this mating period they are believed to be especially aggressive.
Reader's Guide
The blackspot sergeant is a significant species within the Pomacentridae family due to its large size and solitary nature, contrasting with many damselfish that form schools. Its common name derives from the prominent black spot at the upper base of the tail, a key identifying feature. The species is ecologically important in shallow rocky and tidepool habitats, where it plays a role as both a grazer (feeding on algae) and a predator of small animals and plankton. Its aggressive territorial behavior, particularly during mating, influences the distribution and behavior of other fish in these environments. The shift from tidepools to deeper surge zones as individuals mature indicates an ontogenetic habitat change. The species is also culturally notable in Hawaii, where it is known as kūpīpī. Its lifespan of up to nine years and oviparous reproduction with male nest-building contribute to its life history strategy.
Did You Know?
- Juveniles are common in tidepools, while adults move to deeper areas with more surge.
- Males build a nest site in rocky areas to attract females and are believed to be especially aggressive during mating.
More in Clownfish and Damselfish, Part 2 1-24
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