Mandarin fish belong to the family of dragonet (Callionymidae) within the order of Perciformes (percomorph). Preciforms comprises about 160 species in 19 genera. All Perciformes are sea-dwellers and wide spread around the globe. The mandarin fish specifically are small fish native to the coral reefs of the indo-pacific oceans reaching depths of 6-65 ft. (2-20m).These fish have quite distinctive beautiful colors, fat cheeks, and an unusual swimming behavior. All these behaviors together make mandarin fish a popular choice for aquariums.
Although these fish are popular, mandarin fish require very specific conditions in an aquarium and stress easily. Because of this, they are not recommended for beginners.
Size & life expectancy
The adults reach an average length of 3-4″(8-10cm) with the males being considerably larger than the females.
When well cared for, mandarin fish in captivity have a life expectancy of 5 to 10 years of age. They are very difficult to care for so this is not always the case.
Behavior and Characteristics
Mandarin fish is a small little fish with a broad head, big frog like eyes and an assortment of beautiful, elegant fins.
The body is scaly with elaborate fins with patterns of dots, spots, and stripes in orange, yellow, blue and green with a dark border. The males can be identified by being larger than the females and are often more brightly colored. The male will also have an elongated spine on the dorsal fin that is twice as long as the females.
Mandarin fish do not swim in schools and live alone most of the time. They are sedentary and will only move a few square feet away from their hiding spot. They are not aggressive unless two male mandarins are put together in a small aquarium.
In nature, they are found mostly hidden between corals or buried in the sand. They leave their hiding spaces in the early morning and later in the afternoon in search of food. They move slowly and cautiously resting on the sea floor and moving with a few quick, short movements.
Mandarin Fish Care and Nutrition
Mandarin fish spend most of the day looking for food at the bottom of fish tanks and on live rocks. These fish eat live copepods and amphipods living in an aquarium. Due to their particular food requirements, these fish need experienced aquarists.
Feeding your mandarin fish copepods and amphipods:
Mandarin fish can only survive in large, well-established aquariums where there is sufficient growth of copepods. It takes eight months to a year after adding in copepods to become established enough to introduce the mandarin fish.
Copepods require lots of places to hide, breed, and live. Having a bed of live sand of at least 1” (2.5cm) deep as well as lots of live rocks for breeding will help them become well established. Having a sump with a refugium will also help with keeping enough copepods and amphipods separated from the Mandarin for breeding.
both of these species of pods feed on phytoplankton so they must be added to have a complete ecosystem.
Although it can be tough, training mandarin fish to eat brine shrimp is possible. (shown in detail below)
Note: Baby mandarin fish must be fed live copepods and amphipods. Once they become Juvenile fish, you can start training them how to eat frozen brine shrimp.
How to train your dragonet to eat prepared food:
First, move them to a small 10-20 gallon (37-75L) tank to begin training. The walls of the tank should have dirty or non-reflective glass. Otherwise, they will think the reflection is another fish and keep attacking their reflection. This will make it very difficult to feed them.
Since they are a very slow, cautious fish all pumps should be off during feeding so the water stagnates and they can identify the food easily.
Note: It is not recommended to start with live brine shrimp. Live brine shrimp do not spend most of their time swimming around where mandarin fish forage for food (live rocks, tank bottom).
Once the water has become stagnate, add tiny sized frozen brine shrimp to a container to soak for 15 minutes with selcon and garlic pro. These additives increase the protein levels and other vitamins for the fish. Brine shrimp alone don’t have enough nutrients and it is important to enrich their food.
When soaking the brine shrimp is finished, take a little baster and use it to put the shrimp into the tank. It is important to dump lots of shrimp into the tank especially if there is other fish that eat brine shrimp. once the shrimp reach the bottom of the tank, they cautiously might eat them. It can take a few weeks for the dragonet to learn it is food.
Patience is key
It can take a few weeks for the dragonet to learn the brine shrimp is food. Once they become trained on eating the shrimp, they should be fed two to three times a day. This is because they will only eat a few shrimp at each feeding.
If possible, supplementing prepared food with copepods and amphipods will make your Mandarin a healthier, happier fish. These pods will add additional vitamins to their diet and increase the variety of food.