Saltwater aquariums are great because they offer so much color and life. Mandarin fish are one of the most attractive examples; they have lots of different colors and patterns stretched across their body.
Their appearance is what draws people in, but people sometimes bite off more than they can chew. Dragonets are fussy eaters, so their diet needs to be carefully controlled.
These dietary challenges can be difficult to overcome but once they are, this species is simple to care for.
This article explains everything you need to know to keep your mandarin fish healthy, including their ideal tank setups, diet and much more…
|Lifespan:||Up to 5 years|
|Size:||Up to 3 inches|
|Minimum Tank Size:||30 Gallons|
|Tank Set-Up:||Marine: Reef|
|Compatibility:||Peaceful Fish of a Similar Size|
Mandarin Fish Overview
The mandarin dragonet (Synchiropus splendidus), sometimes known as the mandarin fish, is a popular saltwater fish for home aquariums. They are part of the Callionymidae family.
In the wild they’re native to the Pacific, stretching from the Ryukyu Islands to Australia. However, now they can be bought worldwide. Prices range from $20-40 depending on the size and colors of the fish. This is quite a popular species, so it shouldn’t be hard to find stock near you.
It’s popular because it’s one of the most colorful fish you can get. They brighten up any tank, but don’t be tempted to keep them in groups as they will fight with each other.
They are perfect for a reef-type tank, and work well in a community aquarium of similar sized fish.
They are slow-moving fish that spend a lot of their time at the bottom of the tank in the search of food.
Don’t expect too much activity from them, but that doesn’t mean you won’t enjoy watching them. Their patterns and designs are captivating.
Generally, this is a peaceful species that should ignore most fish around them. If anything, they can be quite shy, often choosing to hide away in caves.
Males often fight so they should be kept on their own, or in a pair of one male and one female.
Mandarin Fish Appearance
Its appearance is the reason most people keep them in their tank.
Their body resembles that of a goby but there aren’t many other similarities between the two. An adult rarely exceeds 3 inches.
They have large pelvic fins which allow them to “walk” across the substrate. This often gets mistaken for pectoral fins. The actual pectoral fins are more central to the body and almost transparent. Their eyes appear large and are raised slightly from the body. Each eye is red with big black pupils. They have no scales but can secrete toxic mucus to deter predators.
There are a few different varieties of this species, each with a slightly different pattern.
The striped variety has wavy orange and blue horizontal stripes. Their fins have a similar design, but the oranges can morph into yellows. Their head can be blue or green with bold blue stripes.
Green and red mandarin dragonets look similar to the striped ones, but the oranges are replaced by red and green shades.
You can get spotted mandarin dragonets too which have a completely different design. The stripes are replaced by dark blue spots, bordered by yellow rings. The body is a pale yellow-green.
Sexing these fish isn’t too difficult. Males have longer, pointed dorsal fins. Females can be a little smaller too. These differences make it easier when trying to work out how to mate them.
Habitat and Tank Conditions
In the wild you will find this species in shallow lagoons and inshore coral reefs in the Western Pacific. If you can recreate these conditions in your tank, your fish will feel at home.
The substrates would be silt with an array of corals, rocks and rubble sat on top. A combination of these provides both food and shelter.
Waters are warm and alkaline with little movement and plenty of access to light.
A reef habitat is probably the most common marine tank setup. It’s not too difficult to design one that’s perfect for your mandarin fish.
Some live sands or silty substrates should be used to cover the bottom on the tank. Make sure the layer is thick enough for your fish to bury themselves in, they like to do this when they get stressed.
On top of the substrate you’ll need plenty of rock and coral to create a labyrinth of hiding spots for the mandarins to retreat to. Live rock acts as an important food source.
Around 75lbs of live rock is needed to provide enough food for a single dragonet. They’ll quickly eat through all the copepods that these rocks provide if there’s too few. Any tank that you add these dragonets to needs to be well established, so that the live rock supports a food supply. If the tank is newly setup, you fish will likely starve.
A heater is needed to keep the water between 75-81°F. Maintain pH of 8.1-8.4 and a salinity of 1.023-1.025. There aren’t any special lighting requirements and most standard lights keep the tank well lit.
Slow water movement is preferred so you don’t need a water pump. Plants aren’t a necessity either.
What Size Aquarium Do They Need?
A single mandarin dragonet will need at least a 30 gallon aquarium. The minimum tank size is usually determined by their diet rather than their size. If you can’t fit enough live rock in your tank, they’ll quickly run out of food.
How Many Can Be Kept Per Gafllon?
This isn’t a species you should be keeping in groups, no more than a pair is advisable. Each member of the pair needs their own space and food, so the tank will need to be at least 60 gallons.
Tank Mates For Mandarin Dragonets
These fish are peaceful towards other species; fights are usually only between males of their own kind.
Ideally tank mates will be of a similar size. Larger fish can start to pick on your dragonets and often outcompete them for food, so they go hungry.
This species isn’t an aggressive feeder, so it doesn’t do well when it needs to compete for its food. Mandarin fish need to be kept with other peaceful feeders like seahorses, or with those that eat a different food source.
Live anemones should be avoided too. This fish species spends a lot of time on the bottom of the tank and could be consumed by the anemone.
You should be able to keep a few invertebrates in your tank with the dragonets. Cleaner shrimp and nerite snails can both be kept.
Keeping Mandarin Dragonets Together
Do not keep males together or they’ll start to fight over food, territory and females. Either keep this species on its own, or as a pair of one male and one female.
What Do Mandarin Dragonets Eat?
Mandarin dragonets are a carnivore which means you’re limited with what you can feed them.
In the wild they eat various small creatures that come close by to them, including: copepods, small snails, worms and fish eggs.
They feed continuously throughout the day whenever they find food perched on the substrate or around rock surfaces.
In an aquarium, their favorite food is copepod. This is something they eat naturally and is one of the few things they eat in an aquarium.
Live rock is important in your tank because it will sustain populations of copepods that your mandarin dragonets can eat. The amount of rock you can keep depends on your tank size. If you want their diet to be solely sourced from the live rock, they will need a well-established 70 gallon tank.
If your tank is too small, your fish can completely deplete the copepods and will need some other foods so that they don’t starve. Live brine shrimp are a popular alternative. Frozen Mysis shrimp are good too because they provide a range of nutrients, but you have to wean the fish onto these frozen foods.
To do this you must provide live foods and slowly introduce frozen foods into their diet. As they get a taste for the new foods they will begin to accept them, so you can increase the amount of it you give them.
Thaw the frozen foods before adding them into the water.
Caring For A Mandarin Fish
Once established in the tank, your mandarin dragonets won’t need any special care. As long as you know how to clean the tank effectively, they should be healthy.
Perform water changes every week to prevent pollutants from building up. They can deal with small fluctuations in water parameters, but will still succumb to poor water conditions eventually.
This is a hardy species that is particularly resistant to parasites, but they can get diseases just like any fish can.
There are a few signs to look out for to check their health. These include discoloration, darting, flashing, rapid ventilation and a loss of appetite. A poor diet will make them more susceptible to disease so make sure you’re feeding them well. This is particularly difficult with dragonets as they can be picky eaters.
If you suspect that your fish are ill, check the water parameters and start doing more regular water changes. Alter their diet too if you don’t think they’re getting adequate nutrition.
Though they can live up to 15 years in the wild, a healthy individual rarely lives past five years in captivity.
Mandarin fish can be difficult to breed in captivity, but it’s not impossible.
First you need to establish a mating pair. This isn’t as simple as keeping a male and female together, since not all pairs mate with each other. Individuals can be picky so sometimes it’s trial and error and can take time.
It is easier to purchase an already established pair that has bred before, but this will cost more.
Tank conditions need to be similar to those mentioned above. If these conditions are maintained, and the fish are well fed, then spawning should happen naturally.
This species usually spawns at night. A pair will meet above the reef and release their gametes, the resultant fertilized eggs float to the water’s surface. Up to 200 eggs will be released which will hatch after 12 hours or so. After 3 weeks, the juveniles should develop the colorful designs and resemble the adults.
Spawning can occur every week for a few months if ideal conditions are maintained.
Depending on the tank mates you have, it is advisable to use a separate breeding tank to protect the juveniles from other fish.
Are Mandarin Dragonets Suitable For Your Aquarium? (Summary)
This species can seem difficult to look after at first. It’s not easy to handle their dietary needs.
However once you have mastered this you are rewarded with a beautiful fish.
They are hardy fish that are resistant to diseases and changes in water conditions.
Their colors give your tank a new attraction. There are plenty of varieties to choose from so you can pick the pattern you like best.
These dragonets should get on well with their tank mates, providing they are a similar size and don’t outcompete them for food.
If you have an established reef setup and are looking for new additions, these could be the fish for you.
What do you feed you Mandarin Dragonets? Let us know in the comments section below…