Mandarinfish (Synchiropus splendius) are a popular saltwater aquarium species, mainly due to their unusual coloration which resembles the psychedelic style artwork of the late 60s and early 70s. Although they are relatively peaceful, reef safe, and disease resistant, they are generally considered to be a difficult species for beginning aquarists due to their feeding requirements. In this article, we are going to look at the characteristics, tank conditions, and diet of this beautiful saltwater fish.


Mandarinfish are from the family Callionymidae, also known as the dragonet family. This family is known for cryptic, colorful patterns, scaleless bodies, and large preopercular spines. The coloration of mandarinfish is primarily blue which is very rare for vertebrates. This blue coloration is covered with yellow, orange, and red lines that create a psychedelic style pattern. They have a blunt head and an elongated body. The males of this species have an extended dorsal spine at the front of their dorsal fins. The males are generally larger than the females with a maximum length of around four inches. They are considered to be very resistant to many bacterial diseases and parasites that are common among saltwater aquarium species.

Green Mandarin

Tank Conditions

The main issue with keeping mandarinfish is related to their dietary requirements, although this issue can be addressed by introducing them into a well established reef tank with a large copepod population. Typically, mandarinfish are very peaceful and can get along with most other saltwater aquarium species, except for members of their own species. The water in your tank should range between 73-77°F with a pH between 8.2-8.4. Live rocks and live sand are both recommended and can help to provide your fish with food as well as hiding places.

Fish Food

Mandarinfish are carnivores which feed primarily on small crustaceans found on reefs or other types of live rocks in the wild. In an aquarium, they are usually unwilling to adapt to any type of prepared diet. Therefore, it is essential to have a large population of crustaceans such as copepods in your aquarium. A well establish reef tank is the main type of environment that can encourage this type of crustacean population. Some aquarists have had success feeding live brine shrimp but having a population of copepods available is essential to ensuring the health of your fish. If you do not have a population of copepods living in your tank you need to feed your aquarium with Live Marine Copepods to keep the mandarin alive.

The Takeaway

Mandarinfish are a beautiful species whose coloration and demeanor intrigue many aquarists. However, they might not be suitable for beginning aquarists due to their strict dietary requirements. Be sure to consult with your aquarium specialist in order to determine whether you have suitable conditions in your reef tank for these beautiful fish.

-Richard Bryant
contributor for Aquarium Network

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