The Sergeant Major Damsel Fish is a beautiful, hardy saltwater fish that can make a lovely addition to many aquariums. Larger than most Damsel Fish, Sergeant Majors have dramatic colorations.
The Sergeant Major Damsel Fish was first referred to as Abudefduf saxatilis by Carl Linnaeus (1758). The scientific name abudefduf translates as "father", saxa as "living among rocks", and tilus as "tile-like in color". It is called father due to its bossy, aggressive behavior towards other inhabitants on the reef.
In the wild, Sergeant Major Damsel Fish live in the coral reefs of the Atlantic Ocean. They feed on plankton that they are able to find in the reefs or rocky areas where they live. They tend to be rather aggressive and may bully other inhabitants of the reef. For this reason, Sergeant Major Damsel Fish may not do well with smaller, peaceful fish or with conspecifics in a saltwater aquarium, though they are reef safe, if kept with compatible species. In the wild they live at depths between 1 and 12 meters.
Sergeant Major Damselfish are associated with shallow reefs
This reef-associated fish is commonly observed forming large feeding aggregations of up to a few hundred individuals. These schools swim over shallow reef tops at depths of 3-50 feet (1-15 m).
Sergeant Major Damsel Fish get their names from the five black stripes over there bodies that resemble those of a Sergeant Major's insignia. They inhabit warm reef shallows in the Atlantic Ocean.
Some common names for this fish are Sergeant Major, Damsel fish, Five finger, and Pilotfish. This fish gets its common name "sergeant major" from the stripes that resemble the traditional insignia of the military rank.
General Size Specifications: One of the larger Damsel Fish, Sergeant Major Damsel Fish often reach lengths of six or seven inches (15 to 18 centimeters), though some have been reported to reach eight inches (20 centimeters) in length. Their upper bodies are yellow, often with blue tints. They are laterally flattened. The lower body of the Sergeant Major Damsel Fish is whitish with some gray coloring. There are dark spots on the pectoral fins, one at the base of each fin. There are also five black vertical stripes, which run the height of the body and narrow toward the underside of the fish. The mouth of the Sergeant Major Damsel Fish is small, and the single dorsal fin has a continuous structure.
Feeding and Diet: The Sergeant Major Damsel Fish feeds on a variety of food items including algae, small crustaceans, various invertebrate larvae, and fishes. Stomach content analysis reported benthic algae, pelagic algae, and plankton including copepods, shrimp larvae, fish, and pelagic tunicates as specific prey items of this fish.
Minimum Tank Size: Sergeant Major Damsel Fish, when kept individually, should have an aquarium of at least 20 gallons in size. They are reef safe. Because of their aggressive natures, Sergeant Major Damsel Fish should only be kept with other large fish with similar temperaments.
Habitat: The range of the Sergeant Major Damsel Fish is worldwide in warm waters. In the Atlantic Ocean, this fish occurs from Rhode Island (U.S.) to Uruguay. It is quite abundant on Caribbean Sea reefs as well as around islands in the mid-Atlantic region. In the eastern Atlantic Ocean, its range includes Cape Verde, along the tropical coast of western Africa, south to Angola.
Feeding and Diet: Sergeant Major Damsel Fish can be maintained quite nicely on flake food, and are often offered brine shrimp, algae, and frozen foods.
Breeding: Spawning among Sergeant Major Damselfish mates occurs on rocks, shipwrecks, pilings, and reef outcroppings where the male sergeant major prepares the nest. Courtship rituals include males actively chasing the female during the morning hours. During this time, the males build nests. During spawning, approximately 200,000 eggs are released. These eggs are salmon or red colored, oval-shaped, and 0.5-0.9 mm in diameter. Upon fertilization, the eggs turn greenish at 96 hours and contain a deep red yolk. An adhesive filament attaches the egg to the bottom substrate. The male Sergeant Major takes on a bluish color while guarding the fertilized eggs. He guards them until they hatch which occurs within 155-160 hours following fertilization. This guarding of the eggs, characteristic of the family Pomacentridae, is unusual since most reef fishes have a planktonic stage. The larvae reach 2.4 mm in length approximately 36 hours after hatching. They are deep-bodied, with the caudal and pectoral fins visible, prominent lips, and well-developed jaw bones. Sergeant Major Damsel Fish mate between the months of April and August. Males turn deep blue in color and often become quite territorial.