Sergeant Major

Sergeant Major

Bony Fish

SCIENTIFIC CLASSIFICATION

COMMON NAME: sergeant major
KINGDOM: Animalia
PHYLUM: Chordata
CLASS: Osteichthyes
ORDER: Perciformes
FAMILY: Pomacentridae
GENUS SPECIES: Abudefduf saxatilis

FAST FACTS

DESCRIPTION: Dorsal spines (total): 13-13; Dorsal softrays (total): 12-13; Anal spines: 2-2; Anal soft-rays: 10-12. Yellow to gray dorsal, shading to white ventral, with 5 distinct vertical black bars. Faint sixth bar may be present along caudal peduncle. Adult male exhibits dark blue to dark gray background tonality during the mating season, with the black bars concurrently less conspicuous.
SIZE: 10.2-15.2 cm (4-6 in) avg; 22.9 cm (9 in) max
WEIGHT: 200 g (0.4 lbs) max
DIET: Algae, invertebrate larvae, small crustaceans, and small fish
INCUBATION: Species exhibits dioecism. Fertilization is external. Spawns year-round. Species creates nesting site which the male guards.
SEXUAL MATURITY: No data
LIFE SPAN: No data
RANGE: Western Atlantic: Rhode Island (seasonal extreme) to Uruguay (seasonal extreme)
Eastern Atlantic: Mid-Atlantic islands, Cape Verde south to Angola
Western Pacific: Great Barrier Reef, Australia
HABITAT: 1-15 meters in tropical & sub-tropical marine and/or brackish coastal waters
POPULATION: GLOBAL No data
STATUS: IUCN Not listed
CITES Not listed
USFWS Not listed

FUN FACTS

1. Adults will often form large feeding aggregations - sometimes containing several hundred individuals.
2. Adult males adopt a bluish hue while guarding the nesting site.
3. This species is commonly referred to as "sergeant major" as it exhibits five black bars - resembling the insignia of said rank in the military services.
4. Male sergeant majors exhibit a dark blue to dark gray background tonality during the breeding season. Beyond that, sexual dimorphism is minimal; thereby making it rather difficult to distinguish male from female via casual observation.
5. Male sergeant majors guard the eggs during the four days incubation period prior to hatching.
6. For more information about bony fishes, explore the Bony Fishes InfoBook.

ECOLOGY AND CONSERVATION

The current global trend of coral reef depletion could ultimately effect severe change to sergeant major populations; however, there are no currently identified significant threats to the species.

BIBLIOGRAPHY

Bond, Carl E. Biology of Fishes - Second Edition. Saunders College Publishing, 1996.

Humann, Paul. Reef Fish Identification - Florida, Caribbean, Bahamas. New World Publications, Inc., 1992.

fishbase.org

bio.utexas.edu