Adults can grow up to 22.9 centimetres (9.0 in) at maximum length.[2] Normally, they would grow up to 15 centimetres (5.9 in).[2] The largest recorded specimen weighed had a weight of up to 200 grams (7.1 oz).[2]Abudefduf saxatilis has 13 dorsal spines, 12 to 13 dorsal soft rays, 2 anal spines, and 10 to 12 anal soft rays.[2] 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.[2] Adult males have a more bluish coloration and its stripes are less visible.[2] There is a dark spot around its pectoral fin.
They are found in the aquarium trade but are regarded as difficult to breed.[4]
Reproduction
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.[5] 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.[6]
Etymology
Sergeant majors earn their name from their brightly striped sides, known as bars, which are reminiscent of the insignia of a military sergeant major.[6]
^Melany P. Puglisi (1 August 2008). "Abudefduf saxatilis". Indian River Lagoon Species Inventory. Smithsonian Maine Station at Fort Pierce. Retrieved 4 October 2018.