Bicolor Dottyback (Pictichromis paccagnellae)

Description

Bicolor Dottyback (Pictichromis paccagnellae)

Overview

The Bicolor Dottyback (Pictichromis paccagnellae), also known as the Royal Dottyback or False Gramma, is a striking marine fish from the Dottyback family (Pseudochromidae). Native to the Western Pacific Ocean, it is found in regions from Indonesia (Java, Sulawesi) to Vanuatu, including Palau in Micronesia. It inhabits coastal reefs, coral rubble, and crevices at depths of 0–50 meters, typically 0–15 meters. This species is a protogynous hermaphrodite, meaning it can change from female to male when needed, often in pair formation. It grows to a maximum length of 7–8 cm and can live 5–7 years or more with proper care. Its vivid coloration—bright purple/magenta on the front half transitioning sharply to yellow on the rear—makes it a favorite in reef aquariums. Unlike the similar Royal Gramma (Gramma loreto), it lacks a black dorsal spot. Hardy but territorial, it suits intermediate to experienced aquarists.

Care Requirements

The Bicolor Dottyback is relatively easy to care for in a stable marine aquarium but requires specific conditions to thrive and minimize aggression.

Tank Size and Setup

• Minimum Tank Size: 114 liters for a single specimen. For community tanks, 200–300 liters is recommended to reduce territorial conflicts.
• Aquascaping: Provide ample live rock with caves, crevices, and overhangs to mimic its natural reef habitat. This offers hiding spots and territory markers. Avoid open, barren setups, as they increase stress and aggression. A secure, tight-fitting lid is essential, as this species is a known jumper.
• Lighting: Moderate to high-intensity reef lighting enhances its vibrant colors; actinic lights accentuate the purple hue.
• Water Flow: Moderate flow (10–20 times tank volume per hour) simulates reef currents. Use powerheads or wavemakers for circulation.
• Filtration: Strong filtration with a protein skimmer is ideal to maintain water quality, especially in reef setups with corals.

Water Parameters

Stable water conditions are critical to prevent stress, color fading, or health issues. Test weekly and maintain with regular water changes.

• Temperature    24–26°C    Avoid fluctuations >2°C; use a reliable heater.
• Salinity    30–35 ppt (SG 1.020–1.025)    Measure with a refractometer.
• pH    8.1–8.4    Use buffers if needed to maintain alkalinity.
• Alkalinity    8–12 dKH    Supports coral health and stability.
• Ammonia/Nitrite    0 ppm    Undetectable; toxic even at low levels.
• Nitrate    <20 ppm (ideally <10 ppm)    Keep low for reef systems.
• Phosphate    <0.03 ppm    Prevents algae growth.
• Calcium    400–450 ppm    Essential for corals, if present.
• Magnesium    1,200–1,400 ppm    Stabilizes water chemistry.

Maintenance

Maintaining a healthy environment for the Bicolor Dottyback involves routine care and monitoring to replicate its natural habitat.

• Acclimation: Use drip acclimation over 1–2 hours to adjust to tank conditions. Quarantine new fish for 2–4 weeks to prevent introducing diseases like marine ich or velvet.
• Water Changes: Perform 20–30% water changes bi-weekly or 10–15% weekly using RO/DI water mixed with a high-quality marine salt mix. This controls nitrate buildup and replenishes trace elements.
• Tank Cleaning: Siphon detritus from the substrate during water changes. Use a turkey baster to clear debris from rockwork. The fish may hunt small bristleworms, but heavy infestations require manual removal or traps.
• Health Monitoring: Watch for signs of stress (color fading, hiding, reduced appetite) or disease (white spots, rapid breathing). It is hardy but susceptible to ich if water quality falters. Use copper-free treatments and vitamin-enriched foods to boost immunity and color.

Tips: Add the Bicolor Dottyback as the last fish to minimize aggression toward new tankmates. In tanks under 200 liters, keep it as the only semi-aggressive species.

Diet

As a carnivorous micropredator, the Bicolor Dottyback feeds on small crustaceans, zooplankton, and worms (e.g., bristleworms) in the wild. In captivity, a varied, protein-rich diet ensures health, vibrant colors, and reduced aggression.

Recommended Foods: 

• Frozen: Mysis shrimp, brine shrimp, krill, or chopped seafood (squid, mussel, clam).
• Live: Enriched brine shrimp or copepods, especially for new or picky eaters.
• Prepared: High-quality carnivore pellets or flakes with spirulina, astaxanthin, or carotenoids to enhance coloration.

Feeding Regimen: Feed 1–2 times daily in small portions to avoid overfeeding and water pollution. Thaw frozen foods in tank water and soak dry foods in brine shrimp juice or vitamins if the fish is reluctant to eat.

Notes: A varied diet (80% meaty foods, 20% pellets/flakes) prevents nutritional deficiencies. Underfeeding may increase aggression, while overfeeding can degrade water quality.

Behavior and Compatibility

The Bicolor Dottyback is active, bold, and territorial, claiming caves or rockwork as its domain. It hovers near hiding spots, darting out to feed or defend its territory, which can span several square meters in the wild. Initially shy, it becomes confident and engaging, often displaying a “mating dance” during courtship. It is reef-safe with corals and most invertebrates but preys on small ornamental shrimp (e.g., cleaner, sexy, or anemone shrimp) and tiny snails, while ignoring larger invertebrates like hermit crabs, clams, or starfish.

Behavior

• Territoriality: Highly territorial, especially in smaller tanks. It may chase or nip at fish encroaching on its space, particularly those of similar size, shape, or color.
• Activity: Swims actively near rockwork, often peering from caves, making it an entertaining addition to reef tanks.
• Aggression: Semi-aggressive to aggressive, depending on tank size and tankmates. Larger tanks with ample hiding spots reduce conflicts.

Compatibility

Keep only one Bicolor Dottyback per tank (unless in a very large system, e.g., 380+ liters) to avoid deadly fights. Introduce it last to establish dominance without bullying existing peaceful fish. Choose tankmates carefully to prevent harassment or predation.

Compatible Tankmates:

• Robust, active species: Hawkfish, dwarf angelfish, tangs, clownfish, large damselfish, foxfaces, parrotfish, squirrelfish.
• Semi-aggressive: Blennies, chromis, anthias (in larger tanks with plenty of space).

Incompatible Tankmates: 

• Similar-looking or small fish: Royal Gramma, other dottybacks, firefish, dartfish, gobies, small wrasses (may be bullied or eaten).
• Shy or slow-moving: Mandarins, seahorses, pipefish.
• Small predators: Groupers, lionfish, puffers (may eat the dottyback).
• Small ornamental shrimp: Cleaner shrimp, sexy shrimp, peppermint shrimp.

Reef Safety: Safe with corals (SPS, LPS, soft) and most invertebrates, except small shrimp or micro-snails.
In a 200-liter community reef tank, it can coexist with 4–6 robust fish if territories are divided by rockwork or coral structures.

Reproduction

The Bicolor Dottyback is an oviparous (egg-laying) protogynous hermaphrodite, with females capable of becoming males in the absence of a dominant male. Breeding in captivity is rare and challenging due to its aggressive nature, which complicates pair formation. Most specimens in the trade are wild-caught, as captive breeding is not commercially common.

Breeding Process: 

• Pair Formation: Introduce a smaller (likely female) and larger (potential male) juvenile simultaneously in a 200+ liter tank with multiple hiding spots. The dominant fish typically becomes male. Pairing is tricky, as aggression often leads to fighting instead of bonding.
• Courtship: The male performs a wiggling “dance” near his cave to attract the female. If she accepts, she enters the cave and lays 100–1,000 demersal eggs (which sink and stick to surfaces) on the cave wall or substrate. The male fertilizes them externally.
• Egg Care: The male guards and fans the eggs for 7–11 days until hatching, aggressively excluding the female and other tankmates. Hatched larvae (3–4 mm) are planktonic, drifting in the water column.
• Larval Rearing: Larvae require live foods like rotifers, copepods, or micro-plankton. Survival is low without specialized rearing tanks with high oxygen, dim lighting, and stable temperatures (25–27°C).

Challenges:

• Aggression prevents stable pairs; even successful pairs may fight post-spawning.
• Larvae are difficult to rear due to their small size and need for live foods.
• Home aquarists rarely succeed due to the need for controlled conditions and dedicated breeding setups.

Recommendation: Hobbyists should focus on observing natural behaviors (e.g., courtship displays) in a species-only or community tank rather than attempting breeding, which is better suited for professional aquaculturists.

Summary

The Bicolor Dottyback is a hardy, colorful addition to marine reef aquariums, ideal for aquarists prepared to manage its territorial behavior. A 114+ liter tank with ample hiding spots, stable water parameters (24–26°C, 30–35 ppt salinity, pH 8.1–8.4), and a varied carnivorous diet (mysis, brine shrimp, pellets) ensures its health. Regular maintenance (20–30% water changes bi-weekly) and careful tankmate selection (robust, non-similar species) minimize aggression. While reef-safe, it preys on small shrimp. Breeding is rare in captivity due to aggression and larval rearing challenges. With proper care, its vivid purple-and-yellow coloration and lively behavior make it a standout in any reef setup.

Picture for illustrative purposes only. Either come in store to view available stock or request pictures to be sent to you.

Please Note: Due to variations within species resulting from age, region, sex, etc., the actual livestock may not look identical to the image. Approximate size range may also vary between individual specimens.