Family: Callionymidae Picture of a MandarinfishSynchiropus splendidusPhoto courtesy: Seth Weintraub
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Our lil green Female Mandarin, Maze , is in love with our lil Blue spotted Watchman Goby,Joe, They sleep side by side Every Night, we have Never seen anything like... (more)  Tim

   The Mandarinfish is one of the most striking of the smaller marine fish! It is probably the fish that is singly most responsible for enticing people into the marine aquarium hobby!

   Mandarinfish usually move around a lot in search of food and are really beautiful and fun to watch. They are so cute when they "perch" on their pelvic fins on the bottom of the aquarium or the decor!

  NOTE: Mandarinfish do best in a well-established reef and are only recommended for experienced reef keepers. This is because they thrive only on a large and constant supply of live copepods: interstitial crustacians & worms.

For more Information on keeping this fish see: Guide to a Happy, Healthy Marine Aquarium

Geographic Distribution
Synchiropus splendidus
Data provided by
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Callionymidae
  • Genus: Synchiropus
  • Species: splendidus
Mandarinfish, Synchiropus splendidus
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Extreme close up of a Mandarinfish

The Mandarinfish is one of the saltwater fish that often draws people into the hobby. This is a male, as can be seen by the first rays of the dorsal fin being much longer than the rest. While these fish have been raised in captivity and learn to feed on pellets, they are much like seahorses and need to be fed several times a day. Just dropping in pellets when you feed your other fish in a large tank is not enough since they may not get enough food or may be more interested in the live creatures crawling on the rocks. Keeping them in a smaller tank to monitor their weight is best rather than dumping them in a larger tank they can get lost in. If you have a tank with at least 100 pounds of live rock that has been well seeded, that will support one mandarin. If there are other pod eaters then you will need more live rock than 100 pounds. Avoid corals that are near the bottom and have tentacles like the Elegant Coral, since a bumbling Mandarin can easily find itself stung by that particular coral and die. This was a sad experience I personally had and will never have a Mandarin with such a coral again.

Mandarinfish mating, Synchiropus splendidus
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Well fed Mandarinfish mating in captivity

This is a great video that can identify that odd behavior your male and female mandarins may be displaying! Mandarins have been bred in captivity and trained to eat pellets. This has helped the survival rate of these beautiful fish! They cost up to 4 to 5 times more than the wild caught Mandarinfish, however, their survival rate is worth the cost!

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Maintenance difficulty:    This fish is easy to keep if you have the right aquarium set-up. See "Maintenance" below for a full description.

Maintenance/Foods:    Mandarinfish are omnivores. They will usually eat live brine, bloodworms, and tubifex but this diet is usually not sufficient to keep them over the long term. In the wild they eat small crustaceans (and other benthic organsisms). The latest on some of the newsgroups is that each one needs anywhere from 75 to 150 pounds of live rock to survive. We have kept one in a 125 gallon reef that is doing fine and all he eats is whatever he finds on the rocks. With most fish variety is the key. Feed them anything they will eat and try lots of different things. Live brine, worms, formula I, and formula II, flakes, etc. The mandarin seems to only go for live food however. A mature aquarium with live rock really helps provide the natural food they need.

Habitat: Natural geographic location:    The Mandarinfish are found in the Western Pacific from Java to Japan, the southern Barrier Reef, and the Caroline Islands. Usually found at depths of 1 to 18 meters.

Social Behaviors:    Male mandarins can only be kept singly or with other females. Only one male per aquarium though!

Sex: Sexual differences:   The males are somewhat larger than the females, have longer fins, and the first ray of the dorsal fin is about twice as long as the female's. The fish pictured at right above is probably a male since the dorsal fin is elongated.


   The following breeding information was contributed by Aaron in our guest book:

  "Mandarinfish only spawn in the evening and exhibit very unique mating behavior. If a pair of them are healthy enough, they will begin spawning occasionally just after lights out.
   The male and the female approach each other and begin to "dance" in a spiral up the water column. They release sperm and egg as they rise. The spawn are planktonic for some time, but will grow to a couple mm in length in a couple days.
   If there are other kinds of fish in the tank, the spawn should be isolated. I know this info is relatively general, but I have not personally mated Mandarins (I only have a large enough tank for one fish)."

For more information about recent concerns as well as mandarinfish breeding habits check this article at National Geographic.

Light: Recommended light levels:    No special requirements.

Temperature:    No special requirements. Normal temperatures for marine fish is between 74 and 79 degrees fahrenheit.

Length/Diameter of fish:    Mandarinfish adults can grow to 10.0 cm (4.0 inches).

Minimum Tank Length/Size:    A minimum 60 gallon aquarium is recommended since a minimum of 75 pounds of live rock is needed in order to sustain them.

Water Movement: Weak, Moderate, Strong    No special requirements.

Water Region: Top, Middle, Bottom    Usually spends most of its' time on rockwork or live rock near the bottom.

Availability:    This fish is readily available and is inexpensive.

Author: David Brough. CFS.
Lastest Animal Stories on Mandarin Fish

Tim - 2017-05-06
Our lil green Female Mandarin, Maze , is in love with our lil Blue spotted Watchman Goby,Joe, They sleep side by side Every Night, we have Never seen anything like it

diane Stegman - 2011-01-17
I am not sure how to feed this fish. I put in brine frozen shrimp and didn't touch it. Any suggestions?

  • Enoch Park - 2015-11-01
    Dear Ms. Stegman, Mandarin dragonets are generally finicky eaters; not many are captive bred, so not many will touch frozen food. Make sure that your mandarin is a 'blue mandarin.' That term means that that mandarinfish has been captive bred and might accept frozen food. When buying one, make sure that the mandarin has been fully 'weaned' onto frozen food. You can train a mandarin to accept and even depend on frozen or pellet food, but trust me and my experience; that is a very long and tedious process. Generally, mandarins are to be left to the experts. Good luck! -Enoch
CRRose - 2011-04-28
I have a male mandarin in my 40 gallon reef that is doing excellent and growing well. He eats anything frozen (especially Nutramar Ova) though I'd like to get him eating New Life Spectrum pellets as well. These fish are easy to care for in any sized tank provided that the owner is willing to work with them and train them onto other foods. It is important to choose a mandarin that is not skinny with a sunken-in stomach, as they often won't start eating again. Putting them in a breeder net or similar and offering foods several times a day (siphoning out anything left over) is an excellent way to train them. Once they are eating well, they can be released. No one willing to invest a little time should be scared away from these lovely little fish.

  • Charlie Roche - 2011-04-29
    Thank you for the information. It is always great to hear from someone who has been through it and can help others. Thank you.
Shane Arthur - 2009-02-21
I have a Synchiropus splendidus in a 20 gallon nano reef, have trained him to come eat pellets twice daily with my clowns. He eats well and is gaining weight normally.