Facts on the Sergeant Major Fish

Sergeant major fish (Abudefduf saxatilis) are damselfish who, in nature, abound in warm ocean environments of both the Pacific and Atlantic Oceans. As a species, sergeant major fish are extremely turf-oriented and defensive, particularly the males, who diligently protect their nests against the threats of passersby. They are common additions to aquarium life.

  1. Appearance

    • These schooling fish are roundish, and they weigh up to 0.45 pound. Lengthwise, they can sometimes get to 9 inches. As far as coloration goes, sergeant major fish appear in two separate modes for handy camouflage purposes. In sandy locales, their coloring takes on a subtle look and blends in with the landscape, with elements of pale yellowish-green and gray. In murky locales, however, they take on black appearances. The edges of their bodies are adorned with five vertical stripes, which essentially vanish in dim lighting. They have little mouths and sharp teeth. In times of reproduction, male sergeant major fish turn deep blue.

    Diet

    • In their natural habitat, sergeant major fish consume a healthy array of sustenance -- fish, shrimp, crabs, phytoplankton and algae. They readily dine on most foods they can access. As pets in tanks, sergeant major fish usually eat herbivore blends, algae, fish flakes, shrimp and frozen foods.

    Living Environments

    • Sergeant major fish amass in sizable units often made up of hundreds of specimens. Some typical haunting grounds for these fish are the areas surrounding sea-grass meadows, tide pools and the upper portions of reefs. They also often gravitate to rugged reefs, as these settings feature lots of hiding spots. In the aquarium, a single sergeant major fish needs a tank of at least 20 gallons. For small groups of around three fish, a tank with 50 gallons' capacity or higher is preferable. For bigger groups, look for a tank that can hold 150 gallons or more. Never place them in the same tanks as fish who eat them in the wild, such as family Labridae wrasses. Keep the water temperature between 72 and 78 degrees.

    Naming

    • The "sergeant major" moniker of the Abudefduf saxatilis species is a reference to the striping on their bodies. The striping of these family Pomacentridae creatures is thought to look like the U.S. military's sergeant major emblem.

    Breeding

    • As an oviparous species, sergeant major fish youngsters hatch after exiting their mothers' bodies as eggs. The fathers work on setting the nests up, typically over stones and amidst debris from broken ships. Spawning occurs in the morning. The mothers release up to 200,000 red or purple eggs simultaneously.