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Steene's Dottyback

Pseudochromis steenei

Steene's Dottyback is a large, fiercely territorial micro-predator from Indonesia. It requires a dedicated semi-aggressive setup with heavy rockwork and a secure lid.

Taxonomy
Class:Actinopteri
Order:Perciformes
Family:Pseudochromidae
Subfamily:Pseudochrominae
Genus:Pseudochromis
Species:Pseudochromis steenei

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Water Temperature

22 - 27 °C

pH Value

8.1 - 8.4

Water type

Marine

Tank level

Bottom

Adult size

12 cm

Minimum tank volume

>= 150 L

Minimum group

>= 1

Species description

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.

Care, breeding and tankmates

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.

Geographic Origin and Distribution

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.

Origin

Cosmopolitan or introducedSouth and Southeast AsiaTropical oceans and reefs

Fish profile

Temperament
Aggressive
This group is notoriously pugnacious and highly territorial, fiercely dominating their chosen area of the reef structure. They will aggressively and unrelentingly defend their chosen cave or crevice from any perceived intruders, regardless of the intruder's size. Despite their relatively small stature, their bold, fearless, and aggressive nature means they can easily dominate an entire tank if not carefully matched with appropriate tank mates. Impeccable planning of the community dynamic is utterly crucial prior to introducing them.
Diet
Carnivore
They are strictly carnivorous predators, relying on a diet rich in meaty foods in the wild, such as small crustaceans, worms, and zooplankton. In the aquarium setting, they should be offered a highly varied diet including mysis shrimp, enriched brine shrimp, and finely chopped seafood. High-quality marine carnivore pellets or flakes can also be offered as supplementary daily food. Ensuring a diverse and protein-rich diet helps maintain their vibrant coloration and overall immune health.
Sex ratio
Solitary
These species often exhibit distinct sexual dimorphism, with males typically growing larger and displaying much more intense and varied coloration than the females. It is highly recommended to keep them entirely singly or as a carefully matched, confirmed male-female pair. Keeping multiple males or unsexed individuals in the same confined tank almost universally results in severe territorial aggression and inevitable fatalities. Even in very large aquariums, establishing a peaceful pair requires ample physical territory and visual barriers.
Feeding frequency
Twice daily
Due to their highly active nature and carnivorous diet, they should be fed small portions at least two to three times a day. Frequent, smaller meals closely mimic their natural foraging behavior across the reef structure. Avoid feeding large, infrequent meals as this can lead to digestive issues and result in excess uneaten food decaying in the tank. Closely observing their feeding response ensures they are getting adequate nutrition without overfeeding.
Bioload
These fishes produce a relatively small amount of waste given their diminutive size and moderate metabolic rates. A well-established biological filtration system and regular protein skimming can easily handle their output. Routine water changes are sufficient to maintain pristine water quality and a healthy environment. Overfeeding should be carefully avoided to prevent unnecessary spikes in bioload and nutrient accumulation.
Flow
Moderate
These species thrive in moderate to strong water flow that realistically mimics the dynamic currents of their natural coral reef environment. Excellent water movement helps keep their environment properly oxygenated and carries suspended food particles past their favorite hiding spots. Furthermore, adequate flow aids in keeping the tank free of detritus accumulation, which is essential for maintaining high water quality. Powerheads should be strategically positioned to create varied and turbulent flow patterns.
Jump risk
Yes
Like many similar reef fishes, they possess a sleek, torpedo-like body shape that allows them to dart quickly when navigating the rockwork. This agility makes them exceptionally prone to jumping out of the water when startled, harassed, or simply exploring. A tightly fitting lid, glass canopy, or fine mesh screen is absolutely essential to prevent them from tragically escaping the aquarium. Open-top aquariums are highly discouraged for these species, and immense caution is required during routine maintenance.
Reproduction
Oviparous
They are well-known to be secretive cave spawners, where the male actively entices a receptive female into a secluded crevice to lay a mass of sticky eggs. After fertilization, the male vigorously guards, cleans, and aerates the egg mass until the fry hatch a few days later. Breeding in the home aquarium is certainly possible but presents a massive challenge, primarily due to the immense difficulty of providing appropriate microscopic live foods for the tiny larvae. Providing numerous complex rocky caves dramatically increases the likelihood of spawning behavior if a compatible pair is established.
Compatibility & tankmates
Highly aggressive
They are highly territorial and generally aggressive towards smaller or similarly shaped fishes, especially other benthic species. They should not be kept with peaceful, shy species as they will likely harass them relentlessly. It is best to house them with larger, robust tank mates such as moderately sized angelfishes, tangs, or larger damselfishes. Caution is advised when keeping them with small ornamental shrimp, as these invertebrates may be viewed as a natural food source.
Tank level
Bottom
They primarily inhabit the lower to middle vertical regions of the aquarium, consistently staying close to the complex rockwork. They spend a significant majority of their time cryptically darting in and out of tight caves, crevices, and rocky overhangs. While they may bravely venture out into open water columns during feeding time, they always quickly retreat to the safety of their established territory. A tank equipped with intricate and porous aquascaping provides the perfect ideal environment for their natural benthic behaviors.

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level
3.6 ± 0.5 se
Resilience
High (less than 15 months)
Phylogenetic uniqueness (PD50)
0.5
Bayesian Length-Weight
a = 0.00501, b = 3.1
VulnerabilityLow vulnerability (10 / 100)

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

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Last updated: 06/30/2026
Steene's Dottyback (Pseudochromis steenei) Care Guide & Tank Setup | Atlarium