𝐓𝐡𝐞 𝐌𝐚𝐧𝐝𝐚𝐫𝐢𝐧 𝐅𝐢𝐬𝐡 𝐒𝐮𝐫𝐯𝐢𝐯𝐚𝐥 𝐆𝐮𝐢𝐝𝐞:

𝐅𝐞𝐞𝐝𝐢𝐧𝐠, 𝐓𝐚𝐧𝐤 𝐒𝐞𝐭𝐮𝐩, 𝐚𝐧𝐝 𝐏𝐫𝐨 𝐓𝐢𝐩𝐬 𝐟𝐨𝐫 𝐒𝐮𝐜𝐜𝐞𝐬𝐬

To Watch Our Video On Mandarins Click Here

Introduction

There’s just something about mandarin dragonets, isn’t there? If you’ve ever watched them flutter around the rocks, showing off their psychedelic colors like living pieces of abstract art, you know exactly what I mean. These little reef gems are often called "dream fish" for a reason.

But let’s be honest—they aren’t always the easiest fish to keep. Mandarin fish have a reputation for being picky eaters, and they need a mature tank with lots of natural food sources. Don’t let that scare you, though. With the right setup and a little preparation, they can absolutely thrive in your reef tank.

This is one of those fish that rewards patience and careful planning. Trust me, once you see them happily hunting through your rockwork, you’ll feel like a reefkeeping pro. Let’s get into everything you need to know to make that happen.

Quick Species Snapshot

Types of Mandarin Dragonets: Green vs. Spotted

There are a few types of dragonets in the aquarium trade, but the two most common (and beloved) are the Green Mandarin and the Spotted Mandarin. While they share a lot of care requirements, they have their own quirks and beauty that are worth knowing about before you pick your new reef superstar.

Green Mandarin (Synchiropus splendidus)

This is the classic, the showstopper, the one that usually first comes to mind when you hear "mandarin fish." The Green Mandarin isn’t entirely green — it’s a dazzling mix of electric green, bright orange, neon blue, and gold swirls. Photos rarely do them justice.

They are two color varieties, the "Green" and the "Red". They are the same species but they usually have more red or green in their colorations. 

Identification:

• Extremely popular due to their psychedelic, almost painted appearance.

• Males have taller, sail-like dorsal fins.

• Females have more subdued dorsal fins but equally stunning coloration.

Behavior and Care:

• Constant, graceful forager — they glide through the rockwork like little underwater butterflies.

• Feeding: Like all mandarins, they require established copepod populations but can sometimes be trained to take prepared foods.

Tamara’s Pro Tip: The Green Mandarin is one of my personal favorite reef fish of all time. Under the right lighting, they glow like neon signs. If you’ve built a tank you’re proud of, this fish will show it off perfectly.

Spotted Mandarin (Synchiropus picturatus)

Also called the Psychadelic Mandarin or Picturesque Dragonet, this variety looks like it’s been splattered with a painter’s palette.

Identification:

• A deep green to blue base body.

• Bright, almost neon-blue spots scattered across its body and fins.

• Orange outlines along the spots and fin edges.

• Slightly chunkier body shape compared to the Green Mandarin.

Behavior and care:

• Peaceful and always foraging.

• Requires the same mature tank and pod populations.

• Sometimes reported to be a touch more accepting of prepared foods than Greens, though this varies.

Appearance and Behavior

Mandarins are truly one of the hobby's most colorful fish, almost looking like they were airbrushed by an artist who got a little carried away. Males can be identified by their taller, elongated dorsal fins, while females are a bit more streamlined.

They spend their day slowly gliding over rockwork, poking their snouts into crevices in search of tiny critters to snack on. Mandarins are peaceful and will not bother other fish or invertebrates. In fact, they seem entirely in their own little world, blissfully unaware of whatever chaos might be happening elsewhere in the tank.

• Constant foragers, always on the hunt

• Gentle, non-aggressive temperament

• Natural cryptic behavior, prefer lots of hiding places

Tank Requirements

Mandarins absolutely require a mature, stable tank to thrive. A tank that's at least 30 gallons is a good starting point for a single mandarin, but larger is always better, especially if you’re hoping to keep a pair.

Key tank setup considerations:

• Minimum tank size: 30 gallons for one, 50+ gallons for a pair

• Lots of live rock for natural food hunting

• Mature tank, established at least 6 months to 1 year

• Stable water parameters, with no drastic swings

• Peaceful reef-safe environment

Tamara’s Pro Tip: I like to think of mandarins as "reef tank royalty." They deserve a well-established kingdom before they take the throne.

Lifespan and Long-Term Care

Mandarins live about 3 to 5 years in captivity, though longer is possible with excellent care. The biggest challenge is maintaining food availability over the long haul.

Long-term care tips:

• Regularly observe for weight loss

• Supplement pods consistently and dose phytoplankton to keep the pod growth strong.

• Avoid drastic changes in water parameters

Tamara’s Pro Tip: A healthy mandarin has a round belly and is always busy picking at the rocks. Watch for that!

Feeding Mandarin Fish

Here’s the big one. Feeding mandarins is where things get tricky, but also really rewarding.

In the wild, mandarins eat all day, every day, grazing on thousands of tiny copepods and amphipods. Replicating that natural feeding behavior in captivity is key to keeping them healthy.

Food Source:

• Copepods (Tigriopus, Tisbe, Apocyclops species)

• Amphipods

• Other tiny zooplankton

In captivity:

• Live copepods introduced regularly

• Frozen foods like baby brine shrimp or enriched mysis shrimp (some mandarins can be trained)

• High-quality prepared foods designed for finicky eaters

Tamara’s Pro Tip: If you’re serious about mandarins, consider setting up a refugium to culture pods. It’s like building them an all-you-can-eat buffet in your tank!

To Learn How to Train Your Mandarin to Eat Frozen or Pelleted Food Click Here

Breeding and Pairing

One of the coolest things about mandarins is their courtship dance. If you have a male and female pair, they’ll often rise together in the water column at dusk, spiraling around each other in a graceful mating ritual.

Things to know:

• Males have a taller dorsal fin

• Pairing works best in large, pod-rich tanks

• They lay planktonic eggs that drift with the current

Tamara’s Pro Tip: Watching mandarins spawn is one of the most magical moments in reefkeeping. Keep your lights a little lower at dusk to see if they start their dance.

Common Problems and Troubleshooting

If your mandarin isn’t thriving, don’t stress—these fish are quirky little creatures, and a few simple tweaks can make all the difference.

1. Problem: Mandarin not eating

Cause: No established pod population, or not accepting prepared foods

Solution: Solution: Boost pod populations with regular dosing or by setting up a refugium. Try feeding live baby brine shrimp to trigger their natural hunting instincts. Consider using a feeding station to train them to recognize frozen or prepared foods. If they simply won't get and are losing weight, you should try to rehome them before they get too thin and they can't recover.

If your mandarin isn’t thriving, don’t stress—these fish are quirky little creatures, and a few simple tweaks can make all the difference.

Tamara’s Pro Tip: If they simply won't eat and are losing weight, you should try to rehome them before they get too thin and they can't recover.

2. Problem: Weight loss

Cause: Outcompeted by faster tankmates or simply not finding enough food between meals.

Solution: Feed in quieter areas of the tank, or during times of lower activity like early morning or lights-out periods. You can also dose live pods at night when mandarins are more active and other fish are less competitive.

3. Aggression from other fish

Cause: Tankmates are too fast, territorial, or aggressive around food sources.

Solution: Avoid housing mandarins with overly aggressive or boisterous fish like dottybacks, larger wrasses, or damsels. Stick with peaceful community species, and provide lots of live rock for hiding.

Tamara’s Pro Tip: If you notice bullying during feeding, create a little rock tunnel or hideaway so your mandarin can eat in peace. If that doesn't work, you might have to re-look at your fish selections.

4. Mandarin hiding constantly

Cause: Stress from new surroundings, strong flow, or harassment by other fish.

Solution: Double-check your flow isn’t too aggressive, and make sure there are plenty of caves and overhangs in your aquascape. Reduce tank disturbances and give your mandarin time to adjust.

Tamara’s Pro Tip: New mandarins are shy. Give them a week or two to relax, and watch from a distance to avoid startling them.

5. Mandarin not picking at rocks

Cause: Pod population has crashed, or water is too “clean” (zero nutrients).

Solution: Re-seed with a variety of pod species, like Tisbe and Tigriopus. Maintain a small level of nutrients in the tank—zero nitrate and phosphate can starve out your pod colonies.

Tamara’s Pro Tip: Pods thrive on detritus and biofilm. A sparkling-clean tank might look nice but can leave mandarins hungry.

6. Sudden decline after initial success

Cause: Pod population couldn’t keep up with consumption, especially in smaller tanks.

Solution: Set up a pod hotel or refugium to replenish populations sustainably. If you don’t have a refugium, dose pods regularly, and supplement with training for prepared foods as backup.

Tamara’s Pro Tip: Pods breed best in safe zones like refugiums or pod hotels where predators can’t reach them. Think of it as your mandarin’s pantry!

Setting Up a Copepod Buffet

If there’s one thing that separates a thriving, plump mandarin from a struggling, skinny one, it’s a never-ending, self-replenishing supply of copepods. Think of it like keeping a salad bar stocked for your little dragonet guest of honor—except way more alive and wiggly!

Here’s how to build the ultimate copepod buffet:

1. Set up a refugium

A refugium is your best friend when it comes to natural copepod production. Packed with live rock, macroalgae like chaetomorpha, and live sand, it creates a safe haven where pods can breed without predation. Plus, it helps stabilize nutrients and improves overall water quality.

2. Add “pod hotels” to your refugium or display tank

These are structures made from porous materials (think ceramic media or bio-blocks) that give copepods tons of hiding places to live, breed, and multiply. Even better, they let you harvest pods if you need to transfer them to your display tank.

3. Seed your tank with live copepods

If you don't start off with live rock you might have to seed your tank with copepods. Start strong by seeding your system with multiple species like Tisbe, Tigriopus, and Apocyclops pods. Each type has its own habits: some are better at living in rockwork, others thrive in the water column. A mix keeps your pod population diverse and resilient.

4. Dose phytoplankton to feed your pods

Pods need food too! Regular dosing of live phytoplankton keeps your pod population thriving. Think of phytoplankton as the fertilizer for your copepod garden. Feed the pod farm, and the pod farm feeds your mandarin.

5. Avoid overstocking pod-hungry fish

Mandarins are not the only pod grazers in town. Wrasses, dragonets, and scooter blennies all love a copepod snack. If you have a pod-hungry community, you’ll need to boost your pod production accordingly—or limit their numbers to give your mandarin a fighting chance.

6. Direct dosing (if you don’t have a refugium)

No refugium? No problem—kind of. You can absolutely add pods directly into your display tank, but remember: without a dedicated breeding ground, your display will quickly become an all-you-can-eat buffet for your fish. You’ll need to re-dose regularly, and this can become expensive over time.

Tamara’s Pro Tip: Rotate your pod species like you rotate your fish foods. Variety keeps your population robust and adaptable, and your mandarin will appreciate the menu change!

Mandarin Fish Myths

1. Myth: Mandarins will eat whatever you feed the rest of the tank.

• Truth: Not true. Most mandarins are live food specialists and need pods or trained feeding.

2. Myth: You need a massive tank to keep a mandarin.

• Truth: Size matters, but tank maturity and pod availability are more important. I have seen a very successful 30 gallon tank house a mandarin that started with a captive bred mandarin that ate both pelleted food and frozen mysis. However, it takes dedication and frequent feedings for that to be a possiblity.

3. Myth: All mandarins starve in captivity.

• Truth: With the right setup and dedication, many mandarins thrive in home aquariums especially captive bred ones!

Are Mandarin Fish Right for You?

Mandarins are some of the most rewarding reef fish to keep, but they definitely aren’t for every setup. Here’s what you need to know to decide if they’re right for you.

Mandarins are best suited for hobbyists who:

1. Have a mature, stable tank

Ideally, your aquarium should be at least 6 months to a year old. Why? This gives time for microfauna like copepods and amphipods to establish a healthy, self-sustaining population. Young tanks often don’t have enough natural food for a mandarin to thrive.

2. Enjoy culturing pods or setting up a refugium

Mandarins are “micro-predators” that spend their day grazing on live foods. A refugium stocked with macroalgae and live rock acts as a natural breeding ground for pods, giving you a continuous food source. Some hobbyists even set up “pod hotels” in their sump to keep populations robust.

3. Are committed to careful observation and care

These fish require you to pay attention—really pay attention. Watching your mandarin’s belly size and behavior is key to catching issues early. If they start to lose weight or hunt less actively, you’ll need to step in fast with additional food or pod replenishment.

4. Love a peaceful reef environment

Mandarins thrive in calm, mellow tanks without aggressive or boisterous fish. A peaceful community tank with plenty of rockwork is their perfect home.

Tamara’s Pro Tip: If you enjoy the process as much as the payoff, mandarin keeping is deeply rewarding. Watching them hunt pods in your tank all day is like having your own mini underwater safari.

Mandarins are not ideal for:

1. Tanks under 6 months old

New systems simply don’t have the microfauna populations mandarins rely on.

2. High-energy predator setups

Tanks with wrasses, triggers, large tangs, or puffers are too aggressive and fast-paced for mandarins. These peaceful grazers will get outcompeted or stressed.

3. Fish-only tanks without live rock or refugiums

Without rockwork or a pod breeding ground, your mandarin won’t have a natural food supply. Unless you’re committed to constant manual feeding, they’ll struggle in these environments.

4. Tiny nano tanks

Unless you are extremely diligent about pod dosing and prepared foods, tanks under 30 gallons are too small to sustain a stable pod population for mandarins long term. I would highly discourage anyone from trying.

Tamara’s Pro Tip: Before you bring home that beautiful mandarin, spend a month or two “prepping the pantry.” Seed your tank with pods and give them time to multiply—you’ll thank yourself later!

FAQs About Mandarin Fish

1. Can I keep multiple mandarins?

• Yes, if your tank is large and has abundant pods. Pairs are magical!

2. Will mandarins eat frozen food?

• Some will, with patience and target feeding. Success varies but starting with captive bred will up the odds of success.

3. How long should I wait before adding a mandarin?

• At least 6 months, ideally 9-12 months for pod populations to establish.

4. Can they live in nano tanks?

• It’s not recommended unless you have an external pod culture and are very experienced.

Conclusion

Mandarin dragonets are truly one of the crown jewels of reefkeeping. Yes, they require extra effort, but the payoff is seeing these vibrant little gems flutter gracefully through your aquascape every day. With a well-planned tank, healthy pod populations, and a little patience, your mandarin fish can thrive and become the star of your reef.

Tamara’s Pro Tip: Patience pays off big time with mandarins. Set up their environment first, let it mature, and enjoy the reward of one of the most beautiful fish in the hobby.

Happy Reefing!