Keeping The Rainbow Belly Pipefish Microphis deocata

By: | Date: 08/17/2016 | 2 Comments |
Female Rainbow Belly Pipefish displaying sail

Female Rainbow Belly Pipefish Microphis deocata showing her breeding sail.

Microphis deocata, also known as Indian Royal Green Pipefish or Rainbow Belly Pipefish, are one of very few completely freshwater pipefish species on the planet. They are a small brownish green pipefish that grow to a maximum of 6.5″. What makes this species truly unique is the brightly colored sail the females of the species use for courtship.

Microphis deocata are found in the Brahmaputra River that runs between India and Bangladesh. They are a threatened species as a result of seasonal flooding within these two countries and are not commonly available commercially in the aquarium trade. There is very little information available at all on this species and so I am offering my experience with this fish for enthusiasts who hope to keep them in the future.

5 drab pipefish in a small containter

A group of Microphis deocata shortly after acquisition.

I have been working with this species for 15 months now. I discovered Microphis deocata as an aquarium fish completely randomly; I typed “oddball fish” into Google in May of 2015. The search led me to a forum where I discovered an image of a female Microphis deocata. I was immediately hypnotized by the beauty. I couldn’t believe they were real. I did another google search for “Microphis deocata” and that search only returned a handful of results. I was surprised by the lack of information available about the care of this species.

One of those few search results led me to Rachel O’Leary. She was able to obtain Microphis deocata in the past so I shot her an email hoping she could help me find them. That same day, Rachel got back to me with her advice and pointed me in the right direction and they were actually available! It was a Friday night so I had to wait until Monday to place the order. Over the weekend I set up the tank (always good to keep spare cycled sponge filters in your other tanks, you’ll never know when you might need them), placed the order on Monday and by Tuesday they had arrived. Little did I know how lucky I was to find them that quickly because they haven’t been available at all in 2016.

Setting Up The Aquarium For Microphis deocata

Over the course of the 15 months that I have been working with this species there has been a lot of experimenting with set ups. The basics though for all the set ups have been: sponge filtration rated for higher than tank size, and a nano hang on filter (with a pre-filter) rated for 3-5 gallons just to create a slight current. No heater in the summer and a heater set to 74 degrees during the winter.

Planted aquarium with driftwood

20 gallon Aquarium setup for the pipefish. Inset shows the full tank with canopy.

I have had these fish in various sized tanks ranging from 10 gallons, to 20 gallons (both long and high) as well as a 40 breeder. What little information I found online recommended a Ph between 6-7.6. My tap water is 7.8 and moderately hard. I have been using dechlorinated tap water with them since day one. The only special treatment I give their water is adding a few Indian Almond Leaves occasionally at their bi-monthly 25% water change.

The original set up I had them in was a 20 long, with gravel substrate, and Vallisneria across the entire length of the tank. I also utilized floating plants such as frogbit and duckweed to dim the light, as well as provide a natural canopy that would allow the pipefish to feel safe and secure while also providing them with roots and leaves at the surface that they could hunt in. They seemed to thoroughly enjoy this set up.
Within a month of having them, I witnessed the first breeding display.

A week or two later, I noticed one of my males had a pouch full of eggs and I was beyond excited. However, this is where I ran into my first issue. I realized that the fry could fall into the gravel and never make it back out. I decided to move the male to a bare bottom tank where he could give birth. With each passing day his eggs were disappearing, I don’t know whether he absorbed them for his own nutritional benefit or if he dropped them and then ate them, but they were nowhere to be found. He only had 1 egg left in his pouch and as luck would have it, my first baby M. deocata was born in July 2015. It was smaller than a grain of rice! But back to the set ups!

Before returning the father to the main setup with the rest of the adults, I decided to pull the large gravel from the set up and switch to fine sand that way there was no chance the babies could get trapped within the substrate. I found that sand was the way to go as two months later I had another four baby pipefish born. I raised them in the tank with their parents with no issues whatsoever. I also had a pair in a 10 gallon packed with plants, and floating plants that also mated for me.

I ran into trouble when I upgraded the adults to a 40 gallon breeder. I thought they would appreciate the additional space a larger tank would provide, but I was wrong. Their behavior didn’t change at all, if anything, it made hunting for food harder and forced them to utilize more energy. After I had them in the 40 gallon for a couple months, I lost two females. I immediately decided to move them back into a 20 gallon, this time a 20 high.

I truly believe the 20 high is the perfect tank size for this species. They enjoy having both height and length to swim around. They may do well in a 29 gallon aquarium for the same reason. Another thing to note is with a canopy of floating plants, they swim vertically and utilize the height of the tank, without floaters, they stay toward the bottom and swim horizontally.

To sum up what has worked best for me

  • Sponge filters
  • a tiny hang on with a pre-filter on it to create current
  • sand substrate or bare bottom
  • tons of plants both tall and a canopy of floaters
  • temp between 70 & 74
  • 20 long, 20 high, or 29 gallon aquarium

Two Suitable Tankmates

It has taken a lot of trial and error to find appropriate tank mates for Microphis deocata. There are two potential issues with keeping these pipefish with other species. One is that these pipefish are not able to compete for food with most fish who are faster and more active feeders. Microphis deocata need a steady food supply throughout the day if you want them to be healthy enough to breed for you. Having baby brine available to them for the duration of the lights being on for 8 hours is a necessity. Most fish that inhabit the water column will feast nonstop on the baby brine and this could risk the supply running out before the pipefish are satisfied.

The second is the threat to pipefish fry – most aquarium animals would find them a quick snack. When it comes to newborn fry, they are so tiny that really anything can be a threat to them. Through much trial and error, I found two species that make good tankmates. Danionella translucida, an extremely small Danio and Green Babaulti Shrimp. Both of these species are also found in India.

Green Babaulti Shrimp on plant stem

Green Babaulti Shrimp in aquarium.

D. translucida max out at about half an inch and the largest food they can accept is baby brine, and even that is a little too big for them. I feed mine hikari first bites, so they pose no threat to pipefish fry which are large by comparison. D. translucida can also thrive in the cooler temperature required by M. deocata. Green Babaulti shrimp are an algae eating species so too pose no threat to fry and the pipefish also benefit from them because the pipefish can eat newborn shrimplets. These are the only two species I would recommend based on my experiences.

Danionella translucida in palm of hand.

Danionella translucida, an extremely small danio won’t harm pipefish fry


Pipefish targeting brine shrimp

M. deocata about to strike an enriched adult brine shrimp.

Keeping Microphis deocata fed is the most challenging part in caring for them. I tried a number of different types of live foods when the pipefish arrived. I was quickly able to find what worked and what didn’t. These fish live to hunt; they are proving to be impossible to completely frozen train.

Daphnia magna and D. pulex are both too big, even the smallest of either species are too big. They can eat the smallest Moina.

Freshly hatched Baby Brine has proven to be one of their favorites so I hatch it every day for them. It is very important to harvest the baby brine within the first few hours of hatching because after 8 hours their egg sack is fully absorbed and they lose much of their nutrtitional value.

For a while I was harvesting live mosquito larvae wherever I could because this is one of their biggest food sources in the wild. I found that they were able to eat the smaller mosquito larvae, but they would choke on the larger ones. Then the larger ones would go uneaten and eventually transform into flying mosquitos in my house. It wasn’t worth the risk personally to feed mosquito larvae. I also tried flightless fruit flies, but that didn’t work very well. The fruit flies would eventually find their way onto the floating plants and crawl out of the tank.

Adult brine shrimp

Adult artemia make up part of their staple diet.

Live adult brine, enriched for 20 minutes in Vitachem has become their staple diet along with moina and freshly hatched baby brine. I’ve had my Moina cultures crash a couple times and can say with complete confidence that I have had them breeding on just Vitachem enriched live adult brine, and baby brine alone. Also, occasionally I trick them with enriched frozen brine, some do fall for it and eat it, while others will bite it and then spit it out. But they never fall for it two days in a row for some reason. They are extremely smart fish, and I am 100% confident in saying that they recognize me when I come to the tank to feed them. They all swim to the front glass and just float there staring directly at me, as if to tell me how hungry they are.

Every morning they get live baby brine shrimp, moina and enriched adult brine. On the weekdays I feed them the enriched adult brine before and after work. On the weekends I feed them adult brine 3-4x a day, on top of the daily baby brine shrimp and moina.


two pipefish, female with large colorful sail on belly

Female M. deocata displaying sail to male (obscured by female).

Being completely freshwater is not the only attribute that makes this species unique compared to other pipefish. Female Microphis deocata have a very special mating display that not only makes them a standout when compared to other pipefish, but when compared to all freshwater and saltwater fish in general. I would compare it to a display in a male bird more than I would compare it to a display in a fish.

Sexual roles are reversed in this species, with females working to attract the males. Upon sexual maturity, the female develops a breeding “sail.” When she is ready to attract a male for mating, it is unlike anything you’ve ever seen before; she releases a marvelous blue, red, and white striped flap of holographic and translucent skin from her underbelly. Imagine an almond eye shape where the lower half is a decagon and the skin is patterned like a barber pole pattern.

Two pipefish swimming mid-column, female with colorful sail expanded

Pair M. deocata mating dance as male prepares to accept eggs.

The males are drawn to the female the moment she extends her sail. They will jet from wherever they are in the tank to mate with her. It’s as though they are hypnotized by the display into mating with her. That may be hyperbole, but it is really bizarre how quickly they stop what they’re doing to be alongside her.

The mating ritual only occurs within the first half hour to hour of the tank light being on in the morning. It also only occurs a couple times every few weeks, even after 15 months of keeping them, it is still something I look forward to every morning! During the actual mating, the male will align his pouch next to the females’ egg tube, and then the female will retract her sail in order to deposit the eggs into the males pouch. She can deposit eggs into multiple males’ pouches during one mating ritual.

two pipefish with eggs in pouches

Pregnant male M. deocata showing different development. New eggs (left) and embryos visible (right).

Egg development takes anywhere from 3-4 weeks. Keeping the males well fed while they are carrying eggs is extremely important. If there is not enough food available to him, he will drop some of his eggs in order to ensure that the remaining eggs are getting enough nutrients. I have recorded up to 25 eggs in a male’s pouch, however getting them all to hatch has proven difficult. I was able to get 11 to hatch from the batch shown above, but lost them all within a day or two. They may have been born weak. The three batches I was able to raise were: a single fry, four fry, and then five fry in that order.

small pipefish fry

If everything goes well, the fruits of all that hard work are babies! Pictured at 1 week old.

Raising Fry

I have successfully raised 10 fry from 3 different spawns and all 10 have ended up male so there may be an environmental factor in the sexual development of the fry. I have still yet to figure out how to get female fry, but I am very eager to continue experimenting. All the fry I’ve raised to adulthood were fed vinegar eels as well as freshly hatched baby brine from day one! At around four months the young pipefish are able to be sexed, and at around six months they start accepting live enriched adult brine shrimp.

Pipefish fry at different stages

M. deocata fry at different stages. On the left, 1 day old newborn. On the right 1 month old juvenile pipefish.


Keeping Microphis deocata is a challenge, but it is definitely rewarding when you get to see the breeding display, the mating, and the babies being born! The babies are a little difficult to raise, but as long as you hatch baby brine daily, have a sand or bare bottom substrate, don’t house them with tank mates that are a threat, and use only sponge filtration, you should do well. Finding them available for sale is tricky and requires patience. Keeping them well fed is the hardest part about keeping these fish.

Female pipefish head detail

Female pipefish head detail. Notice body of small M. deocata hiding behind female.

If you follow my guidelines and learn from my mistakes, you can keep and breed these fish successfully. They are certainly worth the challenge especially since they are threatened in their natural habitat. Microphis deocata are hands down one of the most magnificent freshwater fish species on the entire planet Earth. We need to do all we can to make sure that this species is still around in the years to come!

About The Author

Michael Aquilina

Michael Aquilina is passionate about animals and has been keeping fish since his early childhood. His grandpa Ron had a pet store when Michael was growing up and was a big influence on his fascination with fish and animals. His father, an avid aquarists taught Michael early about aquariums; giving him a head start and solid understanding of aquariums when most were just beginning in the hobby. His fascination and passion for the extraordinary have led him to this and other unusual pets. He graduated from Rutgers in 2013, and worked at fish stores during his time at Rutgers. Michael can be found on Instagram @aquamike23, where he has more photos and videos of these pipefish with the rest of his menagerie.

2 Responses to “Keeping The Rainbow Belly Pipefish Microphis deocata

  1. Jamie W Says:

    Rotifers sound like a good candidate for feeding these pipefish. Some species of rotifers are around the same size as baby brine shrimp and moina. You might have to hunt around a bit to find a starter culture, but if you were able to obtain an appropriately sized strain, having a continuous culture of them would be less work than keeping up a steady supply of BBS. Plus, as I understand it, they are more nutritional.

    Anyways, thanks for writing this up! It’s great to hear about such a unique species.

  2. Zoe one Says:

    Diet or temperature could play a major role in the sex being all male . A rotifer culture would deffinatly be more nutritious . Mike I follow you on Instagram thanmks for sharing what you know about these little friends . Aloha

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