Steene's Dottyback

Geographical Origin and Habitat: Pseudochromis steenei is native and endemic to Indonesia, particularly found around Bali, Flores, and the Sunda Islands. It inhabits deep outer reef slopes and rocky drop-offs at depths ranging from 10 to 50 meters. It is typically found in current-swept areas rich in small caves, crevices, and sponge formations.

Taxonomy and Morphology: Belonging to the family Pseudochromidae, this species is named in honor of the renowned marine photographer and author Roger Steene. It is one of the larger dottyback species, reaching an adult size of 12 cm. It features a robust, elongated body, a large mouth with sharp teeth, and keen eyesight suitable for predation.

Social Behavior: This is a solitary, highly territorial, and exceptionally aggressive fish. It claims a specific cave or rock crevice as its territory and will defend it relentlessly against any intruders, including fish many times its size. It will not tolerate other dottybacks or similarly shaped bottom-dwellers.

Coloration and Sexual Dimorphism: It displays a distinctive color pattern: a greyish-brown head and anterior body that transitions into a bright lemon-yellow posterior body and tail. It has prominent bright orange rings around its eyes. Mature males generally exhibit more intense coloration and a slightly larger, bulkier head than females.

Aquarium Setup: Requires a dedicated aquarium of at least 150 liters. The tank must feature robust, complex rock structures that provide plenty of caves, crevices, and hiding spots where the fish can establish its territory. A tight-fitting lid or screen is mandatory, as this species is an excellent jumper when startled.

Diet and Feeding: Carnivorous. In the wild, it feeds on small fish, shrimp, and crabs. In the aquarium, it should be fed a protein-rich diet containing frozen mysis shrimp, krill, brine shrimp, and finely chopped table shrimp. It will also accept high-quality carnivore pellets. Feed twice daily.

Water Quality: Maintain standard marine parameters: temperature 22-27 °C, pH 8.1-8.4, and salinity with a specific gravity of 1.020-1.025. It requires efficient biological filtration and moderate to strong water flow. Regular water changes are necessary to keep nitrate levels low, though the species is relatively hardy.

Compatibility and Cohabitation: Highly aggressive and predatory. It is not suitable for community reef tanks. It will harass or kill smaller, peaceful fish (like gobies and firefish) and will consume ornamental shrimp (such as cleaner shrimp). Best kept alone or with large, aggressive tankmates like tangs and triggerfish.

Aquarium Breeding: Demersal spawners. Breeding in home aquariums is highly unlikely due to extreme intraspecific aggression; putting two individuals together often results in the death of the weaker fish. If a compatible pair is formed, the male will guard the egg mass inside a cave until hatching.

Risks and Diseases: The main risk is the potential eradication of smaller tankmates due to its aggressive nature. Physically, Pseudochromis steenei is highly resilient and disease-resistant. However, it can occasionally suffer from fin rot or physical injuries if it engages in fights with larger fish.