Dascyllus are a specific genus of damselfish within the family Pomacentriade. Pomacentridae consists of both damselfish and clownfish, and the damselfish known as dascyllus rest within the subfamily Chrominae. There are about 11 species of dascyllus, all of which are marine fish that inhabit the tropical and sub-tropical waters of the Indo-West Pacific ocean. This includes places like the Solomon Islands, Hawaii and Micronesia. They live in shallow reef areas where they have access to close cover. They’re generally forager fish in the wild, acting as planktivores that consume water-borne zooplankton and feeding secondarily on benthic algae. They will, however, consume nearly any type of food given in a tank whether it’s dry or frozen.
Dascyllus fish are noted to lack warm and cool color coverage on their bodies like other genera of damselfish. Instead, dascyllus exhibit more black and white patterns. As a common damselfish trait, dascyllus stay relatively small. For example, the reticulated dascyllus generally reaches three inches in length and the three and four-striped dascyllus reaches about 4 inches. Some of the bigger species include the domino and Hawaiian dascyllus that can grow as long as half a foot. Despite their size, damselfish in general can be very aggressive. They can be competitive both among members of their own species while forming harems, as well as towards other species of fish. Lifespan would certainly differ between species, but captive dascyllus have been observed to live for more than 10 years.
Damselfish are egg layers who clear a site or piece of hard material like dead coral first for their hundreds of eggs to stick to. First thing after clearing a site, damselfish participate in a mating dance involving rapid swimming and fin movements. The males will often turn a shade darker and may even display white blotches on their body during this time. After courtship, spawning occurs at dawn and the male then adamantly guards the eggs until they hatch. When they aren’t being territorial, some species of dascyllus, like the reticulated dascyllus, can be found in medium-sized schools. Dascyllus are desirable aquarium fish, especially for beginners, because of their beauty, high tolerance of chemical and physical conditions, and high disease resilience. Some of the most popular dascyllus for aquariums into the three spot or domino dascyllus, four-striped or blacktail humbug, and three-striped or white-tailed damsel. These three are also used for testing purposes and breaking in nutrient cycling in tanks. No dascyllus species appears to be in endangered or threatened at this time.