|Sergeant major swimming inshore at Phil Foster Park, Florida|
Distribution and habitat
Abudefduf saxatilis is found in the Atlantic Ocean. Populations in the western part of the Atlantic Ocean are found from the north eastern coast of the United States south to the Gulf of Mexico, the Bahamas, islands around the Caribbean Sea, the eastern coast of Central and South America all the way to Uruguay. In the eastern Atlantic Ocean, they are found from Portugal, Azores, the Canary Islands, Cape Verde, and western Africa. Its distribution remains unclear in the Mediterranean Sea due to possible confusion with Abudefduf vaigiensis and Abudefduf troschelii. Juveniles are common in tide pools while adults are found over coral reefs. Sergeant majors are found at depths of 0 to 40 metres (0 to 131 ft).
Adults can grow up to 22.9 centimetres (9.0 in) at maximum length. Normally, they would grow up to 15 centimetres (5.9 in). The largest recorded specimen weighed had a weight of up to 200 grams (7.1 oz). Abudefduf saxatilis has 13 dorsal spines, 12 to 13 dorsal soft rays, 2 anal spines, and 10 to 12 anal soft rays. This fish is white with a yellow top. It has 5 black or dark blue vertical stripes. A faint sixth stripe might be present on the caudal peduncle. Adult males have a more bluish coloration and its stripes are less visible. There is a dark spot around its pectoral fin.
Individuals of this species form shoals of about several hundred individuals. Sometimes, they get cleaned of parasites by fish species such as gobies in the genus Gobiosoma, Bodianus rufus, Elacatinus figaro, and Thalassoma noronhanum. Sergeant majors also clean green sea turtles along with Acanthurus chirurgus and Acanthurus coeruleus.
In the aquarium
They are found in the aquarium trade but are regarded as difficult to breed.
The sergeant major is an oviparous species in which the males create nests on rocks, reef outcrops, shipwrecks, and pilings where the females lay their egg masses. The males actively chase the females in courtship before the female releases approximately 200,000 ref, ovoid eggs which are attached to the substrate by a filament; the eggs turn greenish after a few days and are guarded by the male. As he guards the eggs the male becomes bluish in colour, guarding them for about a week.
- Rocha, L.A. & Myers, R. (2015). "Abudefduf saxatilis". IUCN Red List of Threatened Species. 2015: e.T188581A1896808. doi:10.2305/IUCN.UK.2015-4.RLTS.T188581A1896808.en. Retrieved 11 November 2022.
- Froese, Rainer; Pauly, Daniel (eds.) (2014). "Abudefduf saxatilis" in FishBase. December 2014 version.
- Atlas of Exotic Fishes in the Mediterranean Sea (Abudefduf saxatilis). 2nd Edition. 2021. 366p. CIESM Publishers, Paris, Monaco.https://ciesm.org/atlas/fishes_2nd_edition/Abudefduf_saxatilis.pdf
- Matthew L. Wittenrich. "Raising Sergeant Majors (Full Article)". Tropical Fish Hobbyist Magazine. Retrieved 4 October 2018.
- Melany P. Puglisi (1 August 2008). "Abudefduf saxatilis". Indian River Lagoon Species Inventory. Smithsonian Maine Station at Fort Pierce. Retrieved 4 October 2018.
- Cathleen Bester. "Sergeant Major". Discover Fishes. Florida Museum. Retrieved 4 October 2018.