The Dascyllus damselfish are often purchased as juveniles because they are so cute–but many members of the genus go from being charming little fish to nasty big fish. While they may not work in every marine fish community, they are well-suited for an aquarium with more assertive tankmates. The reticulate damselfish or reticulate dascyllus (Dascyllus reticulates) is a handsome species that is not as aggressive as some of its cousins (e.g., domino damselfish, Dascyllus trimaculatus).
Difficulty: The reticulate damselfish is almost bullet-proof. It will readily acclimate to aquarium life and accept any aquarium food you toss its way. Feed it frozen foods, like finely chopped seafood, fish eggs, mysid shrimp and preparations for herbivores. The reticulate damselfish will also eat flake food.
Physical description: The reticulate damselfish is a deep-bodied damsel that is pale bluish-gray overall with black-edged scales. There is a black bar that runs from the front of the dorsal fin to the anal fin (which is also dusky in color). It also has black lips. The most similar species is the Indian dascyllus (Dascyllus carneus), which is found on reefs in the tropical Indian Ocean. It has a blacker dorsal fin and has blue trim on the scales. The margined dascyllus (Dascyllus marginatus) is another close relative that is found in the Red Sea and Gulf of Oman. The reticulate damselfish is brown on the front of the body, white on the rear with black fin highlighting, and a black spot at the base of the pectoral fin. Both species are similar to D. reticulates in their husbandry requirements. The reticulate damselfish reaches a maximum length of around 3 inches.
Range: The reticulate damselfish ranges from the Cocos Keeling Islands in the eastern Indian Ocean to Samoa in the Pacific. It lives on sheltered lagoons, patch reefs, reef flats, reef faces and slopes at depths of 1 to 160 feet. The reticulate damselfish is almost always found living among the branches of small-polyped stony corals in the generaAcropora, Pocillopora and Stylophora. Groups of reticulate damselfish hover above their coral colony home and pick off zooplankton that drift in ocean currents. Groups of reticulate damselfish often consist of one male, a number of females and few juvenile fish. The size of the group of reticulate damselfish will be directly correlated to the size of the coral head they are living in (i.e., the bigger the coral head, the bigger the group).
Compatibility: The reticulate damselfish is often peaceable as a juvenile, but as it grows it can become quite bossy. The reticulate damselfish is likely to chase and nip at smaller fish that come near its preferred hangout (often a branching coral colony) and may even harass more passive species to the point of causing them to hide constantly (this type of behavior is exasperated if space is limited). Adult reticulate damselfish are best housed with moderately aggressive species, such as pygmy angelfish, other damselfish, hawkfish, larger wrasses, rabbitfish and surgeonfish. Because the reticulate damselfish is deep-bodied and has a spiny dorsal fin, it tends to be less attractive to predators. Occasionally, a soapfish or frogfish may attempt to ingest a dascyllus only to find that it cannot swallow it completely. In some cases, the would-be predator will succeed in spitting the reticulate damselfish out, but in other cases it may become lodged in the mouth or throat of the larger fish. This can be disastrous for both fish species if the predator is unable to spit out the hapless damselfish. The reticulate damselfish does well in the reef aquarium and groups of these fish may actually benefit small-polyped stony coral colonies. Their presence among the branches of these corals helps irrigate the entire colony with fresh, oxygenated seawater and the ammonia the reticulate damselfish releases may be used by the coral as a nutrient.
Aquarium conditions: The reticulate damselfish should be housed in an aquarium of 30 gallons or more. It actually does best if housed in a small group in an aquarium of 100 gallons-plus. In a larger aquarium, these groups of reticulate damselfish are less likely to cause behavioral problems. Keep the water parameters for reticulate damselfish as follows: pH of 8.1 to 8.4, specific gravity of 1.019 to 1.025 and a water temperature of 74 to 82.
Breeding: The reticulate damselfish is a protogynous hermaphrodite (females can change into males). They are haremic, with the male reticulate damselfish defending a group of female reticulate damselfish. During courtship, the male’s head turns dark. The female reticulate damselfish will lay her eggs on a piece of rubble or shell near their preferred hiding place. The reticulate damselfish egg clutch usually contains over 1,000 eggs. The male reticulate damselfish guards and fans them, and the reticulate damselfish eggs hatch in 2 to 2.5 days.