Mandarin fish is a brightly colored and small member of the dragonet family, which is well known in the saltwater aquarium trade. It is a great choice for an aquarium as it offers so much color and life. This type of fish, however, is quite difficult to keep because of the high maintenance it needs from the keepers to stay healthy. It has specialized diet requirements which need to be fulfilled. Once you have successfully overcome this challenge, mandarin fish is then fairly easy to keep. Due to its small size, people consider this fish as the best pick for nano reef tanks. In terms of temperament, mandarin fish does not have aggressive behavior unless kept with conspecifics and males of the same species. However, you can easily keep a single mandarin with the rest of the small, non-aggressive reef species without any issue.

Keep reading for an even more detailed overview of mandarins about their origin, habitat, breeding mode, feeding, tank size, and much more.

Mandarin Fish – Overview

Common Name

This fish is commonly called mandarin fish. As mandarins belong to the dragonet family of saltwater, they are sometimes referred to as dragonets too.

Scientific Name

The scientific name of mandarin fish is Synchiropus splendidus.

Habitat or Origin

Ryukyu Islands south to Australia

Average Size

Mandarin fish is relatively small in size. It can grow up to a length of 7.6 cm (3 inches).


The appearance and coloration of the mandarin fish are the reason why most people keep this fish in their aquarium. Different varieties of this species have slightly different color patterns. Striped mandarin fish has wavy blue and orange horizontal stripes. Their fins also have the same design, but the orange shade can morph into yellow.

The head can be either green or blue with bold blue stripes. Red and green mandarins also resemble striped ones, but the orange shades get replaced with red or green shades. Spotted mandarin fish are recognized for their pale yellow-green bodies. Instead of strips, their bodies have dark blue spots bordered by yellow rings.

Life Span

The average life span of the mandarin fish is up to 5 years. But this period can be extended for a year or even more if taken care of properly.


Mandarins have a carnivorous nature which means that you have got limited options to feed them. In wildlife, they eat any type of small creatures which comes close to them, such as small snails, fish eggs, and worms. In the aquarium, their food is copepods.

Copepods are one of the few things which they eat in both natural as well as aquarium life. In smaller tanks, where live rocks cannot be kept to sustain copepod populations, live brine shrimps are a good alternative. Frozen Mysis shrimps are also popular because of the variety of nutrients they provide, but for that, you will need to wean the fish onto such frozen foods.

Gender Identification

Identifying the sex of mandarin fish is not too difficult as males and females have distinguished appearances. Male mandarins are present with pointed and longer dorsal fins. Females, however, can be a little smaller in size too. All of these differences make it easier for the aquarist while try to mate them.


Mandarin is a peaceful fish that spends most of its time at the bottom of the tank searching for food to eat. not too much activity can be expected from them. Still, people enjoy watching them because of their captivating patterns and designs. Generally, they have peaceful behavior and ignore most of the fish around them. Males often have aggressive behavior and fight with each other, so it is advisable to keep one pair per tank.


Mandarin fish move slowly and have a peaceful personality. Therefore, their keepers should choose peaceful and non-aggressive coral fish species as tank mates to mandarins. Best compatible tank mates for mandarin fish include Pajama Cardinal, Coral Beauty, Seahorse, Small Damselfish, crabs, and snails. Any sort of a large predatory fish that would show aggression towards mandarins would be an incompatible tank mate for them.

Ideal Tank Conditions

A reef tank habitat is the best marine setup for mandarins. Only one pair of mandarin is advisable. As each member of that pair needs its own space, the tank size should be at least 60 gallons. The ideal tank size for a single dragonet is 30 gallons. Almost 75lbs of live rock is usually needed to provide sufficient food for a single mandarin fish. Silty substrates or some live sands can be used to cover the bottom.

This covering layer should be thick enough for the fish to bury themselves in as they like to do this whenever they are stressed. Plenty of corals and live rocks are needed as they act as an important food source.  In an ideal tank setup, a heater is needed so that the water temperature can be maintained between 75-81°F. A salinity of range 1.023-1.025 and pH of 8.1-8.4 is considered to be ideal. As slow water movement is preferred, no water pump is required.

Water Parameters

Optimal water temperature – 75 to 81°F.
PH values – 8.1 to 8.4.
Salinity range – 1.023 to 1.025.
You don’t need a water pump, as it’s ideal to use slow-moving water.


Mandarin fish is known to have a spawning mode of breeding. If you can establish a compatible breeding pair, it can breed prolifically as well. But one point that should be kept in mind is that before breeding, you need to provide mandarin high-quality food and let them get used to a regular lighting schedule as mandarin fish usually spawns at night time. As mandarins are pelagic spawners, they release their eggs into the water, where they float freely until they get hatched.

Common Diseases

Fin rot, Excess skin mucos, redness at finbase.

Approximate Cost

Due to the popularity of the fish, it’s available in plenty at the same time they cost about 50 Dollars.

What to look at when buying

Look for the active ones, avoid buying Mandarin fish with fin rot, damage fins/reddish finbase.

Species in the Market

Striped Mandarin fish, Spotted Mandarin fish, Red Mandarin fish.