RecifAtHome guide
The mandarin dragonet is one of the most colourful reef fish and one of the most misunderstood. Success depends almost entirely on its food supply: tiny crustaceans called copepods.
In short
- A wild mandarin feeds almost exclusively on live copepods.
- It needs a tank that has been running for at least 6 months, rich in live rock.
- Captive-bred mandarins often accept frozen food, making them much easier to keep.
- Only one male per tank.
Common species
- Synchiropus splendidus: the green-and-blue mandarin with psychedelic patterns.
- Synchiropus picturatus: the spotted mandarin, with black eyespots ringed in green.
- Synchiropus marmoratus, sycorax, Neosynchiropus ocellatus: more discreet, with similar needs.
All these mandarin fish are peaceful and spend the day picking at rocks and sand.
Why copepods are essential
In the wild, mandarins hunt tiny crustaceans on the rocks from dawn to dusk: copepods and amphipods. A wild-caught specimen often ignores dry food and can starve in an immature or undersized tank, even if it appears to be eating.
For a wild mandarin, you need:
- a tank of at least 200 litres, running for at least 6 months;
- plenty of porous rock and, ideally, a refugium with macroalgae under refugium lighting;
- no competing pod-eaters (other dragonets, some wrasses, gobies and dwarf angelfish).
Culturing copepods and seeding your tank
Add live copepods regularly (Tisbe, Tigriopus, Apocyclops) and feed them phytoplankton. Our RAH aquaculture phyto- and zooplankton is produced at our aquaculture facility. A refugium, or simply a copepod breeding box in the sump away from the pumps, helps maintain a stable population.
Captive-bred mandarins: the best solution
Aquarium-bred mandarins, including those bred at our facility in France, are accustomed to frozen food from a young age (brine shrimp, mysis, fish roe), and sometimes fine pellets. They still enjoy copepods but no longer depend on them alone: they are suitable for smaller and younger tanks.
Male, female and pairs
Males can be identified by their taller, pointed first dorsal fin. Two males will fight: keep only one per tank. A pair lives peacefully together and performs a courtship dance every evening as the lights dim, rising together into the water column.
Helping to control flatworms
Mandarins also eat red planaria, the small rust-coloured flatworms that sometimes cover the rocks: this is why they are also listed among our flatworm eaters. They help keep numbers down but cannot eliminate a heavy infestation on their own.
Frequently asked questions
What does a mandarin fish eat?
In the wild, almost only live copepods and amphipods. Captive-bred mandarins also accept frozen food.
What tank size for a mandarin fish?
At least 200 litres, running for 6 months, for a wild-caught specimen. A captive-bred mandarin can adapt to smaller tanks if fed several times a day.
Can you keep two mandarins together?
A pair, yes. Two males, no: they fight.
How much does a mandarin fish cost?
In our range, from around €35 for a wild specimen and €100 to €140 for a mandarin bred in France.
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Guide written by the RecifAtHome team, coral aquaculture in Roche-lez-Beaupré (France) since 2010. Updated: October 2026.