The Sergeant Major is a small, flat, oval fish that grows to 9 inches (23 cm). This fish has two color phases depending on where it is-light color (silvery-gray with a yellow luster on upper sides) when swimming over sandy bottom or high above reefs during daylight, dark gray-blue when hiding inside reef crevices or caves at night. Five black vertical stripes give this fish its military rank name.
Range & Habitat
Warm waters on both sides of the Atlantic Ocean - Rhode Island to Uruguay, S.A., the Gulf of Mexico and Caribbean, and the western coast of Africa. This species swims in large schools of several hundred while feeding in daytime. The Sergeant Major lives in coral reefs and sea grass beds at depths of 3 to 50 feet (1-15 m). Juveniles swim in shallow tide pools near floating sargassum (brown seaweed).
Conservation Status: Not Evaluated
Although not evaluated by IUCN, it is not considered endangered.
Algae, small fish and crustaceans, and invertebrate larvae.
In the wild, juveniles feed by removing algae, molting skin and parasites from the green sea turtle.
Fun Facts about the Sergeant Major
- The Sergeant major also is known as the five finger fish and the pilot fish.
- The male fish prepares and aggressively guards the nest in which the female deposits approximately 200,000 salmon or red colored eggs that turn greenish with red yolks 96 hours after fertilization and hatch within 155-160 hours.
- The male actively protects its offspring after they hatch.
- Egg guarding is specific to Family Pomacentridae; most reef fishes release their eggs and allow them to float freely until they hatch.
- This species forms very large nesting colonies, which make it difficult for predators.
- The Genus Abudefdub means “father” named for the males’ bossy, aggressive behavior among reef inhabitants.
Florida Museum: https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/abudefduf-saxatilis/
Lamar University: https://www.lamar.edu/arts-sciences/biology/study-abroad-belize/marine-critters/marine-critters-3/sergeant-major.html
Georgia Aquarium: https://www.georgiaaquarium.org/animal/sergeant-major/