The Sulphur Damselfish (Pomacentrus sulfureus) is an attractive looking fish. Compared to most Damselfish they have a very small range being confined to the eastern Indian Ocean and Red Sea. Even within their range they are not a commonly seen fish but they are not rare.
The body has an oval shape with a sharpish nose. The base color of the body is yellow as its name implies. There is a prominent black spot in the base of the pectoral fin and younger specimens may have a black dot on the rear of the dorsal fin. There are thin purple lines around the mouth going back towards the eye. They grow up to 10 cm in length but the largest specimens we have observed in Tanzania have been 7 to 8 cm.
SULPHUR DAMSELFISH IN THE WILD
They are not a very common fish on Tanzanian reefs. Usually they are seen on protected reefs to a depth of 12 to 14 meters and are most often seen singularly. They are quick to go into cover at the approach of a diver but if one stays in proximity to them they do come out again. They appear to be territorial and if one returns to the same spot they will be there.
The Sulphur Damselfish is found in the west Indian ocean from Mozambique up to Kenya and the Red Sea. They are also found on the West Indian ocean islands including Aldabra, Madagascar, Reunion, Mauritius and the Seychelles. In Tanzanian waters they are usually found between 3 and 14 meters. They are found mainly on protected reefs and occasionally on shallower less protected reefs. They seem to prefer having a small wall or feature alongside them. On the shallower less protected reefs they will hide in acropora corals.
The Sulphur Damselfish feed predominantly on algae and may supplement their diet on zooplankton.
Little if any research has been done on their mating habits, but they probably follow the normal Damselfish behavior. Pairing before mating is usual and after the male cleans a patch for the eggs, mating takes place. The eggs are demersal and adhere to the substrate. The males guard and aerate the eggs until they hatch.
They are colorful hardy fish and would be easy to keep in an aquarium. However they would undoubtedly become highly territorial. It is almost a certainty that they will harass and beat up more peaceful fish.