Sergeant major (fish)
A striped Atlantic damselfish named for its sergeant-like bars.
The sergeant major, also called the píntano (Abudefduf saxatilis), is a type of damselfish. It reaches a maximum length of about 22.9 cm (9.0 in).
This fish lives in the Atlantic Ocean. In the western Atlantic, its range stretches from the northeastern United States down through the Gulf of Mexico, the Bahamas, the Caribbean islands, and the eastern coasts of Central and South America as far as Uruguay. In the eastern Atlantic, it appears from Portugal, the Azores, the Canary Islands, Cape Verde, and along western Africa. Its presence in the Mediterranean is uncertain because it may be confused with similar species, *A. vaigiensis* and *A. troschelii*. Juveniles are often found in tidal pools, while adults inhabit coral reefs. They can be found at depths down to 40 m (130 ft).
Adults typically grow to 15 cm (5.9 in), though the maximum recorded length is 22.9 cm (9.0 in). The heaviest recorded specimen weighed 200 g (7.1 oz). The fish has 13 dorsal spines, 12 to 13 dorsal soft rays, two anal spines, and 10 to 12 anal soft rays. Its body is white with a yellow top and five black or dark blue vertical stripes. A faint sixth stripe may appear on the caudal peduncle. Adult males develop a bluer coloration, making their stripes less visible, and a dark spot surrounds their pectoral fins.
The sergeant major feeds on invertebrate larvae, zooplankton (such as copepods and shrimp larvae), pelagic tunicates, smaller fish, crustaceans, and various benthic and pelagic algae. It is also known to eat the waste and vomit of spinner dolphins.
These fish form shoals of several hundred individuals. They sometimes get cleaned of parasites by other fish, including gobies in the genus *Gobiosoma*, *Bodianus rufus*, *Elacatinus figaro*, and *Thalassoma noronhanum*. Along with *Acanthurus chirurgus* and *Acanthurus coeruleus*, sergeant majors also clean green sea turtles.
Predators of this species include *Plectropomus leopardus*, *Thalassoma bifasciatum*, *Cephalopholis cruentata*, *Epinephelus striatus*, *Mycteroperca venenosa*, and *Rachycentron canadum*.
The fish appears in the aquarium trade but is considered difficult to breed.
Reproduction is oviparous. Males build nests on rocks, reef outcrops, shipwrecks, and pilings, where females lay egg masses.
Quick Facts
- Taxon
- Abudefduf saxatilis
Facts from the source article.
Lore & Background
The sergeant major is white with a yellow top and five black or dark blue vertical stripes, with a faint sixth stripe possibly present on the caudal peduncle. Adult males develop a more bluish coloration, making their stripes less visible, and a dark spot surrounds their pectoral fins. Juveniles are common in tidal pools, while adults inhabit coral reefs down to 40 meters.
This species forms shoals of several hundred individuals. It feeds on invertebrate larvae, zooplankton, pelagic tunicates, smaller fish, crustaceans, algae, and even the waste and vomit of spinner dolphins. It is cleaned of parasites by various fish species, including gobies in the genus Gobiosoma, Bodianus rufus, Elacatinus figaro, and Thalassoma noronhanum, and also participates in cleaning green sea turtles alongside Acanthurus chirurgus and Acanthurus coeruleus.
Reproduction is oviparous: males create nests on rocks, reef outcrops, shipwrecks, and pilings, where females lay about 200,000 ovoid eggs attached to the substrate by a filament. The eggs turn greenish after a few days and are guarded by the male for about a week, during which he becomes bluish in color. The species is found in the aquarium trade but is regarded as difficult to breed.
Reader's Guide
The sergeant major holds significance as a widespread and recognizable damselfish in the Atlantic Ocean, with a distribution spanning from the northeastern United States and the Caribbean to Portugal, the Azores, and western Africa. Its name derives from its striped sides, which evoke the insignia of a military sergeant major. The species plays a role in reef ecosystems as both predator and prey, feeding on a variety of small organisms and being hunted by larger fish such as Plectropomus leopardus and Epinephelus striatus. Its cleaning behavior, involving both fish and green sea turtles, highlights its ecological interactions. In the aquarium trade, it is present but challenging to breed. The species' distribution in the Mediterranean remains unclear due to possible confusion with similar species Abudefduf vaigiensis and Abudefduf troschelii, reflecting taxonomic uncertainties that persist in the scientific record.
Did You Know?
- It feeds on the waste and vomit of spinner dolphins.
- Males guard the egg masses for about a week, turning bluish in color during that time.
- Its distribution in the Mediterranean Sea is unclear due to possible confusion with A. vaigiensis and A. troschelii.
More in Clownfish and Damselfish, Part 2 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced