Sergeant Major Damselfish - Medium

Sergeant Major Damselfish

The Sergeant Major Damselfish are a very hardy species. They are ideal for beginners but the tank must be large enough.

Sergeant Majors have a silver body with a greenish tinge. There are 5 black stripes that run down the sides of its body, with yellow shading between at the top of the stripes.

The Sergeant Major Damselfish is an aggressive species which as they mature they will become more aggressive. They should not be housed with more docile peaceful fish and care needs to be taken when selecting tank buddies.

When Sergeant Major Damselfish reproduce, they change color to a deep blue, which almost hides their black stripes. A white patch also appears on the males’ face.

The male will make a temporary spawning site and try to entice females by signal jumping. This consists of bizarre movements up and down and making noises. The female can spawn up to 20,000 eggs, which the male guards until they hatch around a week later.

It is difficult to breed these fish in captivity, eggs are small, and it is not easy to rear the fry. In a tank community, other animals such as crabs, wrasse, and stars will eat damselfish eggs.

They normally grow to a length of 5.9 inches (15 centimeters) however in the wild some specimens have been measured at 8.6 inches (22 centimeters)

Life expectancy is around 6 years in the wild and up to 15 years in captivity.

In the wild, Sergeant Major Damselfish can be found on coral reefs, usually in shallow waters to a depth of around 15 meters.

They live in the Indo-Pacific region, around the Red Sea, Madagascar, Sri Lanka, Indonesia, Australia, and the Gulf of Thailand.

Tank Recommendations for the Sergeant Major Damselfish

These Damselfish need a tank that is a minimum of 75 gallons (284 liters).

Sergeant Major Damselfish are suitable for both reef and fish-only tanks. Providing them with hiding places in rocks and crevices will help reduce aggression with other tank mates.

This is an active species that swims a lot, they appreciate areas in the tank with a strong current and need a larger tank than other Damsels.

Suitable Tank Buddies

Sergeant Major Damselfish is one of the more aggressive Damselfish and so keep this in mind when selecting tank mates.

Usually Compatible

You can keep Sergeant Major Damsels either on their own, as a pair in a group of 5 or more. Large semi-aggressive species like Angelfish, Tangs, and large Wrasses also cohabit well with these fish.

Sometime Compatible

Caution is advised if housing this species with aggressive fish such as other Damselfish, Dottybacks, 6-Line, and 8-Line Wrasses.

Rarely Compatible

Fish that are likely to eat them like Sharks and Rays should be avoided. Delicate species such as Seahorse/Pipefish are unsuitable tankmates too, as are small peaceful fish.

Feeding Your Sergeant Major Damselfish

Sergeant Major Damselfish are omnivores. They are not fussy eaters and enjoy a mixture of meaty foods such as krill or mysis shrimp and vegetable produce such as spirulina and other algae & zooplankton.

Plenty of protein is recommended for their diet. They can consume most types of flake food, pellets, freeze-dried and frozen products. Live foods such as shrimps, worms or fish can be offered as treats or to help prepare the fish for spawning. They should be fed several times a day, this will also help reduce aggression.