Description
Green Mandarin (Synchiropus splendidus)
Overview
The Green Mandarin (Synchiropus splendidus), also known as the Mandarin Dragonet, Mandarin Goby, or Psychedelic Fish, is a stunning marine fish from the Callionymidae family. Native to the Indo-Pacific, it ranges from the Ryukyu Islands to Australia, including the Philippines and Indonesia, typically found on coral reefs, lagoons, and rubble zones at depths of 1–18 meters. Renowned for its vibrant coloration—greenish-blue with orange, red, and yellow wavy patterns—it has a broad head, large pelvic fins, and a distinctive dorsal fin (larger in males). Reaching up to 8 cm in length, it can live 10–15 years with proper care. Its beauty makes it a favorite for reef aquariums, but its specialized diet and slow-moving nature make it challenging, best suited for experienced aquarists with mature tanks.
Care Requirements
The Green Mandarin is delicate and requires a stable, mature aquarium with specific conditions to thrive. Its dietary needs and sensitivity to poor water quality demand careful attention.
- Tank Size and Setup: Minimum Tank Size: 114 liters for a single specimen; 200–300 liters recommended for community tanks to ensure ample food and space.
- Aquascaping: Provide a mature tank (6+ months old) with abundant live rock and a fine sand bed (2–5 cm) to support a healthy population of copepods and amphipods, its primary food source. Include caves, crevices, and low-flow areas for resting. A tight-fitting lid is essential, as mandarins may jump when stressed.
- Lighting: Moderate reef lighting enhances its vivid colors; no special requirements beyond standard reef setups.
- Water Flow: Low to moderate flow (5–10 times tank volume per hour) mimics lagoon conditions. Avoid strong currents, as mandarins are slow swimmers.
- Filtration: Strong filtration with a protein skimmer maintains pristine water quality, critical for this sensitive species. Refugiums with macroalgae (e.g., chaetomorpha) support copepod populations.
Water Parameters
Pristine water conditions are vital to prevent stress or disease. Test weekly and maintain with frequent water changes.
- Temperature 24–26°C Stable; avoid fluctuations >1°C.
- Salinity 30–35 ppt (SG 1.020–1.025) Use a refractometer for precision.
- pH 8.1–8.4 Buffer if needed to maintain alkalinity.
- Alkalinity 8–12 dKH Supports coral health, if present.
- Ammonia/Nitrite 0 ppm Undetectable; toxic at trace levels.
- Nitrate <5 ppm (ideally <2 ppm) Very low for sensitive species.
- Phosphate <0.03 ppm Prevents algae and stress.
- Calcium 400–450 ppm Essential for corals, if applicable.
- Magnesium 1,200–1,400 ppm Stabilizes water chemistry.
Maintenance
Maintaining a pristine environment is critical for the Green Mandarin’s health, given its sensitivity and reliance on live prey.
- Acclimation: Drip acclimate over 2–3 hours to adjust to tank conditions.
- Quarantine for 4–6 weeks in a separate tank with live rock to ensure it is eating and free of parasites like marine ich.
- Water Changes: Perform 10–20% water changes weekly using RO/DI water mixed with marine salt to maintain low nitrates and replenish trace elements.
- Tank Cleaning: Siphon detritus from the substrate gently to avoid disturbing copepod populations. Use a turkey baster to clear debris from rockwork. Maintain a refugium to sustain live prey.
- Health Monitoring: Watch for stress (lethargy, faded colors, weight loss) or disease (white spots, labored breathing). Mandarins are prone to starvation if copepods are scarce and susceptible to ich if water quality declines. Use copper-free treatments and vitamin-enriched foods to boost immunity.
Tips: Ensure a robust copepod population before introducing the fish. Avoid adding to new tanks (<6 months old) or with competing copepod predators (e.g., wrasses). Check the tank lid regularly to prevent escapes.
Diet
The Green Mandarin is a specialized carnivore, feeding primarily on live copepods and amphipods in the wild. Its small mouth and picky eating habits make it challenging to feed in captivity, requiring a mature tank with abundant live prey.
Recommended Foods:
- Live: Copepods and amphipods from live rock or refugium cultures. Tisbe or Tigriopus copepods are ideal.
- Frozen: Mysis shrimp, brine shrimp, or copepod blends (thawed in tank water) for trained specimens.
- Prepared: High-quality micro-pellets or flakes with spirulina or carotenoids, though acceptance is rare unless trained early.
Feeding Regimen: Allow constant foraging on live copepods in a mature tank. Supplement with frozen foods 1–2 times daily in small amounts if the fish accepts them. Use a pipette or target feeding to ensure slow-moving mandarins reach food before faster tankmates.
Notes: Train to accept frozen or prepared foods by mixing with live copepods during quarantine. A refugium or copepod dosing (1,000–2,000 copepods weekly per fish) sustains dietary needs in smaller tanks. Starvation is common if live prey is insufficient, so monitor body condition (rounded belly indicates good health).
Behavior and Compatibility
The Green Mandarin is peaceful, shy, and slow-moving, often hovering near the substrate or perching on live rock while foraging for copepods. It is non-territorial but vulnerable to harassment by faster or aggressive fish. Males display larger dorsal fins and may perform courtship dances, raising their dorsal fin.
Behavior:
Slow, deliberate swimmer, foraging continuously for small crustaceans on live rock and sand. Rests in low-flow areas or crevices at night, rarely burrowing. Shy initially, becoming bolder in a stable tank with ample hiding spots.
Compatibility:
Reef Safety: Safe with corals (SPS, LPS, soft) and most invertebrates, including shrimp and snails, as it does not eat them.
Tankmates: Compatible with peaceful fish, e.g., clownfish, gobies, firefish, dartfish, or small blennies. Can be kept singly or in male-female pairs in larger tanks (>200 liters) if introduced simultaneously.
Incompatible: Avoid copepod competitors (e.g., wrasses, dragonets) or aggressive fish (e.g., damselfish, triggers, large angelfish) that may outcompete or harass it. Avoid multiple mandarins in small tanks (<300 liters) due to food competition.
Notes: In smaller tanks (<200 liters), keep as a solo specimen. Ensure ample live prey to prevent starvation in community setups.
Reproduction
The Green Mandarin is an oviparous species with sexual dimorphism (males have larger, pointed dorsal fins). Breeding in captivity is possible and increasingly common in aquaculture, producing captive-bred specimens that are hardier and more likely to accept prepared foods. However, it remains challenging for hobbyists due to larval rearing difficulties.
Breeding Process:
- Pair Formation: In a large tank (200+ liters), introduce a male and female simultaneously. Males are larger with a prominent dorsal fin, females smaller with a rounded fin. Pairs form through courtship displays, often at dusk.
- Courtship: Males perform a “dancing” display, raising their dorsal fin and circling females.
- Spawning occurs in open water, with pairs rising together, releasing pelagic eggs and sperm simultaneously.
- Egg Care: Eggs (1–2 mm) drift in the water column with no parental care.
- Larvae (2–3 mm at hatch) require live foods like rotifers and copepods for 20–40 days until metamorphosis.
Challenges: Larval rearing is difficult due to their small size and need for constant live foods. Maintaining water quality (24–26°C, high oxygen, low nitrates) is critical. Aggression is minimal, but food competition can disrupt spawning.
Recommendation:
Purchase captive-bred specimens, which are more adaptable to aquarium diets. Hobbyists should focus on observing courtship behaviors in a species-only or community tank rather than attempting breeding, which is best for professionals with larval rearing systems.
Summary
The Green Mandarin (Synchiropus splendidus) is a breathtaking but challenging addition to reef aquariums, prized for its psychedelic coloration and unique behavior. A mature 114+ liter tank with abundant live rock, a refugium, and stable water parameters (24–26°C, 30–35 ppt salinity, pH 8.1–8.4) supports its needs. Frequent maintenance (10–20% weekly water changes) and a diet reliant on live copepods (supplemented with frozen foods) prevent starvation. Its peaceful nature makes it compatible with non-competitive, reef-safe fish, but avoid copepod predators or aggressive species. Breeding is possible but difficult for hobbyists due to larval rearing challenges; captive-bred specimens are recommended. With meticulous care, it thrives as a stunning, delicate reef fish.
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.
