Paradise Fish Care, Breeding, & Tank Mates

There are three species of paradise fish that are popular among aquarists today. Two look similar, except for the shape of their tails. Macropodus opercularis sports a forked tail, while Macropodus ocellatus has a rounded tail shaped like a spade. Generally, M. opercularis is referred to as paradise fish, while M. ocellatus is usually called the “round tail” or “Chinese” paradise fish. The third species, called the black paradise fish (Macropodus spechti), resembles your typical paradise fish aside from coloration. The black paradise fish is a steely blue and black with little patterning or red.

Despite their differing looks, caring for any paradise fish is about the same. I consider the Chinese and black paradise fish to be slightly more challenging due to their specific dietary preferences, but once that’s taken care of, they’re just as easy as their forktailed counterparts.

They also have similar temperaments, usually being described as fast, active, curious, and outgoing fish. Their personality is comparable to a betta’s, so if you like personable fish, you’ll love these guys! As a bonus, they’re temperate fish, which means they don’t need heaters as long as your house is sufficiently comfortable. They also make a fantastic pond fish if you want to get into ponds or summer tubbing!

For the sake of simplicity, this article will focus on the paradise fish M. opercularis, but know that most of the care information applies to all three species.

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Table of contents

Distribution & Natural Habitat

The natural habitat for the paradise fish is south of the Yangtze River (Chang Jiang) system in China, which includes Hainan Island and Taiwan, central and northern Vietnam, Ryukyu Islands, Japan, Korea, Malaysia, Cambodia, as well as the northeastern part of Laos. Non-native populations have also been found in the United States and Madagascar and are thought to be extant.

The paradise fish prefer lowland habitats with warm, slow-moving, stagnant water conditions. They’re found in blackwater rivers, streams, irrigation canals, oxbow lakes, artificial reservoirs, and rice paddies. However, this species has also been found at higher altitudes, with fresh, cold, fast-flowing streams, though I don’t recommend attempting to create the latter environment at home.

Aquarium Care

If you want to get into “summer tubbing” or outdoor ponds, the paradise fish is a good – albeit unorthodox – choice. Be sure to put them out once temps consistently stay above 50 F at night, and pull them out before temps drop below 50 F at night. They can handle temps up to 90 F, but they live the longest at temps under 72 F, so be sure you get a deep enough tub without a ton of aeration to keep the temperature gradient in the pond.

They breed well and produce beautiful fry outside in the summer (likely all the live food), so if you want a fun, easy, and slightly different summer project, these guys are prefect for the job! Just make sure you have some homes lined up when you bring the fry back inside in the fall.

Tank Specs

For a single paradise fish, I would recommend a minimum tank size of 20 gallons. Preferably larger because they can grow to 4” and they’re quite active, so they’ll need a decent amount of room to swim. A 20 long would be a better choice, with a 30 long or larger being ideal.

Paradise fish are obligate breathers, meaning they have to go to the surface to gulp air, so you’ll want to make sure that the top of your tank is covered and secured. Similar to the killifish and bettas, paradise fish are avid jumpers that are known to end up on the floor, which can injure or even kill them.

Like most labyrinth fish they need a tight-fitting lid for humidity as well. Since they breathe air but live in water, the air they breathe needs to be humid to prevent damaging their labyrinth organ. Dry air can lead to something similar to a respiratory infection in humans. Unlike most other air breathing fish, the air doesn’t need to be warm to prevent damage and there’s evidence that paradise fish could actually benefit from a cool period during winter months.

Stocking

In general, it’s best to avoid getting males unless you’re planning on breeding or keeping them solo. Like most gouramis, males will spar relentlessly if given the chance. They also tend to be more aggressive and territorial overall. Regardless if you plan on keeping multiple females or a single male with some females, it’s best to introduce all the fish at the same time to prevent the established fish from picking on the new-comers.

If you’re planning on keeping more than one paradise fish, a good rule of thumb to remember is 20 gallons minimum and an extra five gallons per additional fish. So, you can keep four paradise fish comfortably without overcrowding in a 35-gallon tank. Again, longer is better and females are safer than males.

Decor

These guys can get jumpy with bright overhead lights, so I suggest floating plants, light dimmers, or both for their tank to help calm them down a bit. Additionally, blackwater seems to make them calmer as well since it’s harder to see through and seems much more natural for them.

They enjoy branches, root structures, driftwood, and other nooks and crannies to explore or seek shelter around. Adding dried leaf litter and similar debris will give the tank a more natural feel, as well as providing additional coverage for your fish.

Leaf litter will encourage microbe colonies to develop, add beneficial tannins, and tint the water a natural color. Some of my favorites for these guys include bamboo leaves, palm fronds, and Nyla palm flowers. You can grab some of these from Tannin Aquatics or just grab some blackwater extract and call it a day.

You might want to consider skipping the substrate. It’s not needed and it’s easier to maintain without it. If you plan on breeding, I advise you definitely skip any sort of substrate. If you want to go with substrate, HTH Pool filter sand mixed with river stones would be my top choice for a natural-looking low-maintenance setup. You can check if your local hardware store carries this type of sand near you, but I suggest buying it in-store since it’s less markup.

If you want a heavily planted tank with a natural sediment-type look, I suggest some crushed leaves, bark bits, or coco bracts over your aquascaping soil to take out some of the “man-made” vibe. My favorite planting soils are below!

Best Plants For Paradise Fish

Paradise fish like densely planted tanks and enjoy floating plants (as long as there’s space to breathe at the surface.) If you have more than one or two paradise fish, an abundance of plants allows each fish to establish a defined territory by acting as a territory border and sight blocker. Plants are particularly important if you plan on breeding since they allow the female to retreat from the male if he becomes a bit too – shall we say amorous? – for her liking.

Look for low light plants that can take a nibble or two and do well in room temp water. I would suggest bushy or floating plants as the best candidates, but mosses are a popular option as well.

Java Moss

Water Wisteria

Guppy Grass

Guppy Grass

Lighting & Filtration

A slowly bubbling sponge filter and some subdued lighting is all you really need to keep paradise fish happy. While they can be found in higher-flow areas, they prefer slow moving or still water. When the water is choppy they tend to avoid building bubble nests, which is a fascinating and entertaining behavior to watch.

I don’t suggest hang on backs, canisters, or sumps for these guys for a few reasons. The first being that their tank is usually too small for it to be worth it. The second reason being that they generally produce too much water flow for them, even when turned down as low as they can go.

If you don’t know where to start with filter or an air pump, I have some of my most used and abused equipment below:

Water Care

Provided your tank is properly cycled, you can get away with relatively few water changes. 25% weekly or 50% bi-weekly being the farthest I’d go with these fish. Of course, no fish does well with ammonia, nitrites, or nitrates, but all things considered these guys are pretty tolerant.

One of the bigger concerns with any surface breather is the oily-looking surface scum that can accumulate on the surface of the water (biofilm.) There aren’t any formal studies on the effects of biofilm on surface-breathers, but some hobbyists insist that it’s bad for them and they can develop illnesses. If you run your sponge filter, it should be just enough surface agitation to break up large masses of biofilm.

Like any fish, they need chlorine and heavy metals removed from their water sources. I use Prime, but I have some other water supplies below to make sure your paradise fish stays healthy.

Feeding Paradise Fish

In their natural habitat in the wild, paradise fish are predators. They will feed on smaller fish, as well as smaller aquatic animals such as zoobenthos and planktonic invertebrates. In tanks, they’re more omnivorous and wholly unfussy with food.

Much like bettas, they’ll often beg for food and eat until they (literally) explode if you let them, so make sure you’re careful not to give them too much. This is especially true with live foods. If you’re worried about overfeeding because you like to see them eating (guilty!) it’s safe to overfeed smaller foods a little bit every so often.

You’d be surprised how willingly bigger fish will chase down tiny food.

Paradise fish will gladly munch live or frozen mosquito larvae, blood worms, white worms, daphnia, grindal worms, wingless fruit flies, blackworms, brine shrimp, and any other wiggly-squiggly treat. If you’re more into prepared foods, they do well on floating pellets like Bug Bites or Vibra Bites and freeze-dried foods. However, for breeding purposes, live and frozen are the best.

Paradise Fish Diseases

Generally speaking, these guys are pretty hardy. They made it through the hobby before the days of heaters, tank lights, or even prepared fish foods (they were fed table scraps!) But they can come down with a few diseases, here are the most common ones (meds for each are listed in the water care section above!)

Lymphocystis (LCDV)

Costia

Bloat

Fin Rot & Tail Rot

Constipation

Paradise Fish Tank Mates

When looking for paradise fish tank mates, look for fish that do well at room temperature, like low-flow environments, and are hardy (or fast) enough to deal with any potential aggression. Any fish that looks similar to a paradise fish will likely be viewed as a rival by male paradise fish – and sometimes females! So you’ll want to avoid gourami, betta, and most rainbowfish species, to name a few.

You’ll also want to avoid anything that can be view as a snack, there’s some hit or miss success with smaller shrimp species, but fish smaller than 1.5″ will likely be out. Another consideration is how they eat. Slow-eating or shy fish will likely be out-competed for food with the more boisterous and food-loving paradise fish if they eat the same things.

Bristlenose Plecos (Ancistrus sp.)

Breeding Paradise Fish

Paradise fish are bubblenesters, and their breeding behavior is similar to other gourami and betta species that build bubblenests. They’re slightly less aggressive than most bettas, but more aggressive than dwarf gouramis, but spawning them isn’t difficult.

Spawning starts with, obviously, a male and a female. You can spawn them in the tank, but most people recommend setting up a separate tank to spawn them in and keeping them separated the rest of the time. If you want to spawn them in situ, I suggest one male and two or three females in a 30 long or a low boy. You can keep them over substrate, but it is more difficult to clean and for the male to retrieve eggs, so keeping plants planted in flowerpots or small plastic tubs usually works better in this situation.

Spawning

Regardless of where you spawn them, you’re going to want to bring their water temperature up to the high 70’s or low 80’s. Some suggest reducing your water level to 6 – 8″ like you would with bettas, but if you’re spawning in a long or a low boy, it really doesn’t matter that much.

When ready, the male will begin constructing a bubble nest while simultaneously harassing the female. When he finishes the nest, the male will then entice the female underneath the nest. Once she’s ready and convinced, they will begin spawning under the nest by “embracing.” The male wraps his body around the female’s body and fertilizes the eggs while she releases them. The embrace will be repeated until all the eggs have been released by the female and fertilized by the male.

https://youtu.be/gX-fwgSiroE

Once the spawning is finished, the male will start attacking the female and trying to run her off. Most remove the female at this point and leave the male to protect the eggs and take care of the fry. However, you can leave them in situ if the tank is large enough and well planted.

If you have more than one female, there is a good chance he’ll spawn with the other females at this point if they come up to him. But he’s not likely to actively pursue spawning with them.

Egg & Fry Care

One spawn can produce anywhere from 80 – 200 eggs on average, but as few as 10 to as many as 500 have been reported.

The water temperature plays a large part in hatching times. The fry usually hatch within 30 to 50 hours, but depending on the water temperature, it could be 48 to 96 hours. Within another 24 – 48 hours the fry will begin free-swimming and the male will go into a frenzy trying to keep them all in the nest.

At this point most breeders remove the male. Though, like with other betta and gourami species, he may or may not be able to stay in until his fry are fully grown. A lot of whether or not he will eat his fry comes down to his experience level and what kind of personality he has. If the fry are in the parent’s original tank, it’s best to remove them at this point since the females could eat the fry even if the male doesn’t.

Once hatched, you should feed the fry a diet of micro worms, vinegar eels, and infusoria. By the time they’re about a week old they should be able to start accepting baby brine shrimp. By two to three weeks old, depending on temperature, their labyrinth organ will begin developing, so you’ll need to make sure the lid is tight and holds humidity so their labyrinth organ doesn’t become damaged at this delicate stage.

By the time they’re about four weeks to a month and a half old, you can start weaning them onto prepared foods like pellets, but make sure you keep frozen and live foods in their diet as well. By the three-month mark they should be ready (or getting ready) to go to their new homes.

Types Of Paradise Fish

M. opercularis comes in a few different color morphs, though most of them are unnamed. They’re usually blue and orange (or red) striped with varying degrees of black markings on their face – from spotted to tiger-like stripes. Their tails come in a few different variations as well.

Generally, most of the ones that have unique patterns or tail forms are hybrids of a few species of paradise fish. They can also hybridize with other gouramis and some betta species as well.

Further Reading & Sources

IUCN – Macropodus opercularis
Science Direct – Lymphocystis, An Overview
UNM Newsroom – UNM scientists discover new antiviral roles for olfactory neurons in fish
PFK Magazine Issue 4 2018 – Comeback Kid