Royal gramma

Geographic Origin and Biotope: Native to the Caribbean Sea and the western tropical Atlantic Ocean. Inhabits coral overhangs, shady caves and reef slopes, often swimming upside down keeping its belly close to the rocky ceilings.

Taxonomy and Morphology: Royal Gramma. It is a Basslet (Grammatidae), not a dottyback. Fusiform and compact body, reaches 8 cm (3 inches). Prominent eyes and a small mouth armed with micro-teeth to catch plankton. Recognizable by the broken lateral line.

Social Behavior: Peaceful, shy but proud defender of its den (a crevice in the live rock). It will open its mouth wide in a threatening attitude to chase away intruders, without however coming to a physical clash. Multiple individuals fight fiercely in small tanks.

Coloration and Sexual Dimorphism: Unmistakable bicolor: the anterior half is brilliant fuchsia/purple, which fades abruptly into a bright golden yellow in the posterior half and tail. It has a black spot on the dorsal fin and a black line through the eye. Males slightly larger.

Aquarium Setup: Ideal for nano-reefs (minimum 100 liters / 25 gallons). The live rock must be architected to form countless caves, ravines and overhangs. Without adequate hiding places it wastes away from stress. Loves penumbra areas and moderate currents. Cover necessary (they jump).

Diet and Feeding: Planktivorous carnivore (darts from its den to grab morsels and returns). Very adaptable: accepts mysis, frozen brine shrimp, fish eggs, calanus and quickly gets used to high quality carnivore micro-pellets. Feed 1-2 times a day.

Water Quality: Robust, among the most recommended marine fish for beginners. Salinity 1.023-1.025, temperature 24-28°C (75-82°F). Good general tolerance to parameters, but the water must be mature to ensure the abundance of amphipod microfauna.

Compatibility and Tankmates: Perfectly Reef Safe (ignores corals and ornamental shrimp). Gets along with Clownfish, Blennies and small Gobies. Do not pair it with the similar and much more aggressive Pseudochromis paccagnellae (Bicolor Dottyback), which would kill it.

Aquarium Reproduction: Possible. The male builds a tiny nest in his cave weaving pieces of algae. After an elaborate courtship, the female lays filaments of adhesive eggs that the male will vigorously defend until hatching (5-7 days).

Risks and Diseases: Basically healthy, but can contract Ich (Cryptocaryon) if subjected to thermal shocks. Problems almost always stem from aggression by territorial dottybacks and damselfish or from the lack of adequate caves in which to retreat.