Spotted Mandarin Care Guide

Synchiropus picturatus
Minimum Tank SizeVariable, see feeding section
Water Parameters72-78 F, pH 8-8.4, Salinity 1.020-1.025

Spotted Mandarins (Synchiropus Picturatus) offer a middle ground between the scooter blenny and green mandarin in terms of difficulty. They bring a unique look with a solid green body covered in spots. These can either be a solid black or outlined with green and orange circles. While they may look different they are the same species.

Like all members of the dragonet family the Spotted Mandarin spends most of its day searching the tank for copepods and amphipods as its main source of nutrition. They can be trained to eat prepared foods, which is essential for keeping them consistently healthy. Over all they are bottom dwellers that hop about on the rocks and glass.

Feeding & Diet

Spotted Mandarins rely on a steady supply of pods as their main diet. In enormous bodies of water this is easy to sustain, meaning smaller tanks under 50 gallons in size will have difficulties keeping the Spotted Mandarin. Keeping mandarins in smaller tanks, even when supported by a refugium, will often result in the mandarins wiping out the pod population.

Mandarins are able to eat frozen or prepared foods, making keeping them much easier. However they must be trained to eat prepared foods. This is best done in an isolation tank, as other fish will frequently steal the food before the mandarin can try it. With the Spotted Mandarin in an isolation tank first release a few live brine shrimp. Once the mandarin starts to hunt these introduce a few frozen, but thawed, brine shrimp. Keep the balance at 50% frozen 50% live. They will occasionally eat frozen brine shrimp. As this continues adjust the ratio towards more frozen brine and less live brine. Using this method mandarins can be trained to eat prepared foods. Use the same method to train them towards mysis or pellet foods. After they accept your desired food they may be released into the main tank. Mysis is better than brine shrimp, and prepared foods can be better than mysis shrimp.

Note: Training a mandarin to eat prepared foods in the display tank is not impossible, and is actually how I trained my first dragonet, it simply produces more waste and can be stolen by other fish.


Spotted Mandarins are, in my experience, far less aggressive towards other mandarins than other species. The most dominant male will continue to harass other males until removed and harass females for the first day. This will only stress the females a small amount, but males will frequently end up dead after enough harassment. After that they can be kept peacefully. To keep large numbers of mandarins you must have 2-3 females per male.

The Spotted Mandarin will not be aggressive towards any other species of fish or coral. They are somewhat prone to bullying but can swim extremely fast when needed. Tank mates for Green Mandarins should be limited to peaceful or slightly aggressive fish.

Breeding & Sexing

Spotted Mandarins are the easiest mandarin to sex. The females are smaller, have much smaller dorsal fins and are often less colorful. Males have large front dorsal fins and will typically be the aggressor when two mandarins meet.

Breeding Spotted Mandarins in captivity used to be though of as impossible, but in recent years has become much easier thanks to in depth studies. To breed the Spotted Mandarin your water parameters will need to be as follows:

  • Temperature of 75-80 F
  • Salinity 1.024-1.026
  • pH 7.7-8.3
  • 0 Ammonia/Nitrite
  • Near 0 Nitrate
  • >1 Phosphate
  • Frequent Feedings
  • Frequent Water Changes
  • Sand Substrate

Emaciated, malnourished mandarins will never breed and may even turn hostile towards each other. Always give the mandarins plenty of feedings and ensure their health before watching for rises/mating. Spotted Mandarins who have been trained to eat frozen foods are much easier to breed, as a few mysis shrimp will provide much more nutrition than hours of hunting pods.

At lights out, and with tanks on timers just before lights out, the male will begin to swim excitedly around the tank will his fins fully extended. This is him seeking any females in the area. If the female accepts the invitation they will swim together, touching fins. After enough courting they will begin what is known as a ‘rise‘. This is where the mandarins lock fins and swim towards the surface of the tank. At the top of the rise the mandarins will separate and either start another rise or resume normal behavior. After enough rises the mandarins will release their eggs and genetic materials. This can range between 50 and 300 eggs depending on the health of the mandarin. Likewise the fertilization rate will depend on the males health.

To attempt rearing fry remove the eggs from the tank as soon as possible. It is best to turn off any filtration when you first notice the mating to avoid them being sucked in. These eggs should then be placed in an incubator with the temperature between 75-79 degrees Fahrenheit. For the highest survival rate these eggs should be kept suspended in the water column(body of water) by a gentle current. This is easiest to do by using a device known as a kreisel.

Green Mandarin eggs will hatch within 24 hours of spawning, having no more than a body and tail. After 4 days they will form eyes and a mouth, enabling them to hunt small foods such as rotifers and phytoplankton. Continue to feed them these for three weeks. At this point they should be switched to copepods or amphipods, which ever you find easier to provide. I personally always have at least two tisbe copepod cultures running as they are easy to sustain and provide excellent nutrition for mandarins. Pods can be continually purchased, but it is much more expensive.

In the middle of the 8th week they may be trained to eat frozen or pellet foods, but this should still be supplemented by copepods. Refer to the feeding section on training them to eat prepared foods.

Remember: The constant addition of all these foods will result in dirty waters, which fry cannot live in. You will need to perform frequent water changes to prevent this from happening. Use a sieve or micron net of 53 or less microns to catch pods from removed water. These can be placed back into the tank for higher efficiency/no waster food.

Fry will begin assume their final look around 7 weeks after hatching. They can be released into the tank after they reach 1-1.5 inches in size. Remember the male to female ratio still applies and fry are best introduced at lights out. For the best results rearrange the tank before adding the fry to an existing tank. This removes all territories and puts the fry on equal footing with existing tank mates.

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