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.
Disclosure: If you choose to buy a product I recommend – at best – I’ll make some coffee money at no additional cost to you. I work hard to make sure I’m recommending product you’ll love and that I’m not in your face about my suggestions, so if you don’t love it, let me know!
Table of contents
Table of Contents
FAQ
Are paradise fish aggressive?
Can paradise fish live in a bowl?
Paradise fish, like most fish, don’t do well in a bowl. They also grow up to 4″+, so they’re too big for even a large bowl.
Are paradise fish a community fish?
Again, like most fish, the paradise fish does not make an ideal community tank inhabitant. Not only do they not do well at temperatures that most commonly kept fish prefer, but they can also be hit or miss on aggression.
Paradise Fish Classification
IUCN Status: Least concern – last assessed 2010
Class: Actinopterygii are ray-finned fishes, which is a subcategory of boney fishes. These fish are characterized by the bony structures that support their webbed fins. This group makes up nearly half of all living vertebrates.
Order: Anabantiformes are fish characterized by teeth on the parasphenoi (a bone found in the cranium of some ray-finned fishes.) Snakeheads and anabantoids (a sub-order of Anabantiformes) both have a labyrinth organ; this enables them to breathe atmospheric oxygen.
Family: Osphronemidae, commonly referred to as simply “gouramis.”
Genus: Macropodus is a family of labyrinth fish from east Asia that are small to medium-sized. Currently there are nine species in this genus.
Species: M. opercularis
What does Macropodus opercularis mean?
Macropodus is from the Ancient Greek μακρός (makrós), which means “long,” and ποδός (podós), which means “leg,” referring to the long leg-like pelvic fins in the front of the fish.
Opercularis refers to the dark opercular spot on this species. The opercular is the structure that covers the fish’s gills.
Find Other Fish
Looking for something specific? You can discover other fish with similar characteristics! They open in a new tab so you can keep reading too!
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
Difficulty: Easy
Size: 3.9″ (10 cm)
Lifespan: 6 – 8 years
Tank Size: 20 gallons (80 liters)
Diet: Omnivore – pellets accepted
Temperature: 50 – 80 F (10 – 27 C)
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!
Recommended substrates
Fluval Stratum Plant & Shrimp
Rating: 4.5 stars
Price: $42.88 for 17lb
Price per lb: $2.43
The only bad reviews I found on this were against Fluval itself. There were a few people who had opened bags that were taped back up when they purchased this off Amazon from Fluval directly. Buyers from Chewy (linked above) didn’t have that issue. This one seems to be the – almost – undisputed winner among aquarium plant lovers.
ADA Aquasoil Amazonia Light
Rating: 4.8 stars
Price: $26.99 for 7lb
Price per lb: $3.85
The Amazonia Light is supposedly easier to handle, cleaner, and less prone to ammonia spikes it’s original Amazonia counterpart. But, with all that said, everything I read says it’s just as good as the Fluval Stratum and it comes with a much heftier price tag. If you’re not married to ADA, I would suggest Fluval Stratum over ADA just based on the price.
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
Salvinia
Salvinia is a fast-growing plant good for keeping ammonia, nitrates, and nitrites under control. It’s great for providing shelter for scared fish and fry, keeping the lighting intensity down. and making skittish fish feel more secure.
Water Wisteria
Water wisteria is a fast-growing plant good for keeping ammonia, nitrates, and nitrites under control. It’s great for providing shelter for scared fish and fry, keeping cyanobacteria (aka blue-green algae) at bay, and has anti-microbial properties.
Duckweed
Duckweed can be a blessing or a curse. It’s a small floating plant that’s impossible to kill and can quickly and cheaply cover the top of your tank. The tough part is that it’s nearly impossible to fully get rid of once it’s in your tank.
Guppy Grass
Guppy grass is a great floating plant that adds depth, structure, and cover to any tank. It’s a super easy plant to grow and takes up tons of ammonia, nitrates, and nitrites, but – beware – it grows fast and can easily overrun your tank. Overall, it’s an amazing plant to have if water quality is your top concern.
Guppy Grass
Guppy grass is a great floating plant that adds depth, structure, and cover to any tank. It’s a super easy plant to grow and takes up tons of ammonia, nitrates, and nitrites, but – beware – it grows fast and can easily overrun your tank. Overall, it’s an amazing plant to have if water quality is your top concern.
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:
Suggested filtration
These Filters
Rating: 4.4 stars
Price: $5 – $7
I want to give you a name for these, really, I do. But the problem is that they change the name of these things every few weeks – which is insane and annoying.
Nonetheless, these name-swapping off-brand filters are super cheap and work amazingly.
Hikari sponge filter
Rating: 4.8 stars
Price: $7 – $12 *size dependent
Theses things have been around forever, and it’s because people love them. Most of the people who leave bad reviews on them are upset that they didn’t know they needed an air pump or hose and the directions suck – because there are none – which is fair enough.
Otherwise, I’ve heard complaints about these filters very rarely.
Ziss Bubble Filter
Rating: 4.8 stars
Price: $25
Though not a sponge filter, this is a great filter that works well for tanks that need low flow. Cleaning them is slightly more involved, but they do make less of a mess coming out of the tank than normal sponge filters. They are, like HMFs, hard to find in the states and I’m not sure how long they’ll be at the place linked. (Great place to buy plants, by the way.)
Tetra Whisper Air Pump
Rating: 4.4 stars
Price: $5 – $24 *size dependent
These air pumps are super quiet and last forever – plus the price isn’t bad. I will say I haven’t been able to find them this cheap in person though.
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.
Suggested water care & meds
Dechlorinator
My all time favorite is Prime, but it is on the expensive side. It can be a serious life saver in an emergency situation though, which is why I keep it handy. If you’re not into the price, I also use Stress Coat and API’s Tap Water Condition and they work just as well for most situations. If you have issues with your tap containing ammonia, nitrite, or nitrate, I highly suggest Prime.
Aquarium Salt
Rating: 4.9 stars
Price: $3 – $7 *size dependent
I’ve never noticed a major difference between one aquarium salt to another, to be honest, but I use API Aquarium Salt because it’s the most readily available. Aquarium salt is useful for a wide variety of situations and I always suggest you keep this on hand – especially if you’re skeptical of using medications.
Potassium Salt (PP)
Rating: 4.4 stars
Price: $5 – $24 *size dependent
This stuff is a little hard to find and, I’ll be honest, I’ve never used it. Which I find to be fortunate because this stuff sounds like it’s no joke. Here’s what I found on Ultraclear’s website: “… effective against external fish infections from fungi, bacteria & parasites, Trichodinia, Costia, Chilodonella & Flukes. It is also an effective solution for improving water quality & clarity by clearing cloudy water of organics. The Potassium Permanganate Solution is a strong oxidizer.”
Maracyn-2
Rating: 4.4 stars
Price: $14 for 24 packets
Maracyn-2 is the same thing as API’s Erythromycin. It works just as well as API’s on most fungal and some bacterial infections. This includes things like body fungus, cotton mouth, some cases of bacterial-related dropsy, and fin and body rot – but it works on tons of other oddball illnesses as well.
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.
Food list
- Freeze dried tubifex
- Freeze dried blackworms
- Frozen (or freeze dried) bloodworms
- Frozen (or freeze dried) mysis shrimp
- Golden pearls
- Floating pellets (Bug Bites or Vibra Bites)
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)
LCDV for short is a member of the iridovirus family. The iridovirus, if it sounds familiar, was the subject of a popular study about fish smelling viruses. This particular set of virus species causes pin-prick sized white spots, lesions, and/or wart-like growths. They’re all naturally begin by nature unless the host is presented with stress.
Symptoms:
- Wart-like spots
- Skin decay (advanced)
- Open lesions (advanced)
Causes:
- Lymphocystis disease virus 1 (LCDV-1)
- Lymphocystis disease virus 2 (LCDV-2)
- Lymphocystis disease virus China (LCDV-C)
Costia
Although it’s more common in cold-water fish, any fish can get it so long as the temperature range is low enough. It’s a parasite that, unlike ich, is difficult to detect in the beginning stages. Once in it’s advanced stages (which make takes months to present themselves) you’ll likely be able to detect it but, at this point, you have to respond quickly as it’s already been taking a toll for quite some time.
Symptoms:
- Grey or white patches on the skin
- Itchiness
- Scratching
Causes:
- Ichthyobodo (protozoan parasite.)
Bloat
Bloat certainly doesn’t have to be as severe as the picture, but you get the idea. Bloating is an accumulation of gas, fluids, or unpassed food present in the fish. Although I have no proof, I suspect this is why most people search “how to tell if [insert fish species] is pregnant” even if they can’t get pregnant. There is a difference between a bloated fish and a fish that’s eaten too much – the fish that ate too much will act normal whereas the other usually won’t.
Symptoms:
- Your fish’s stomach is distended without raised scales
- Fish may appear to be in some sort of discomfort and avoid swimming or other usual activities
- May not be pooping
Causes:
- Intestinal blockage
- Constipation
- Internal bacterial infection
- Internal growths/tumors
Fin Rot & Tail Rot
Fin rot and tail rot are the same thing and are caused by gram-negative bacteria that eat away at your fish’s fins, leaving them ragged and choppy looking. Depending on the severity, this bacteria could open the door for fungal infections or eventually turn into body rot (where the bacteria starts eating the body of the fish.)
Symptoms:
- Fins look like they’ve been chomped on
- Fins are slowly shrinking
- Faded coloration on the fins (not to be confused with new growth)
Causes:
- Poor water quality
- Stress
- Prior untreated injury in combination with poor water quality
Constipation
Constipation usually clears up on its own, but some remedies include feeding blanched or canned peas to herbivores. For omnivores or carnivores, brine shrimp and daphnia (live, if you can) are usually a quick and painless fix for both of you. Salt baths may also be suggested in severe cases.
Symptoms:
- Stringy, white, and/or clear feces
- Bloating
- Lethargy
Causes:
- Hexamita (HITH)
- Lack of fiber
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.)
Most plecos aren’t suited for the average aquarium, some growing up to two feet long – not the bristlenose pleco. They’ll happily munch on algae, green beans, zucchinis, cucumbers, sinking algae wafers, and of course leftovers and fish poo – although leftovers and poo make for a literally shitty diet.
White Clouds (Tanichthys albonubes)
These fish are best kept in groups of eight or more, though 10 is better. There’s little information of just how far spread these fish are, but they’ve been observed slow-moving white and blackwater streams in and around China.
pH: 6.0 – 7.0
dKH: 5 – 20
Temp: 60 – 72F (15 – 22C)
Size: 1.5 – 2″ (3 – 5 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Asian Stone Cat (Hara jerdoni)
Asian stone cats are tiny, adorable catfish that need to be kept in groups of six or more. They need plenty of hiding places, a good deal of dissolved oxygen, and a low flow.
pH: 5.6 – 7.6
dKH: 8 – 15
Temp: 64 – 75 F (18 – 24 C)
Size: 1.2″ (3 cm)
Temperament: Peaceful, can be shy
Swimming: Bottom
Cherry Barb (Puntius titteya)
Cherry barbs are small and peaceful. They’re undemanding and pack a colorful punch when cared for correctly, making them an ideal community inhabitant. They’re shoalers, so they need to be kept in groups of 6 or more to bring out their best behavior.
pH: 6.0 – 8.0
dKH: 2 – 20
Temp: 68 – 81 F (20 – 26 C)
Size: 1.5 – 2″ (4 – 5 cm)
Temperament: Peaceful and active
Swimming: Top to midwater shoaling
Zebra “Danio” (Brachydanio rerio)
Zebra danios belong to the minnow family. They’re fast, outgoing, peaceful, and need room to swim with their shoal (6 or more being ideal.) They can handle a range of temperatures and water conditions – from stagnant to faster-flow, making them a versatile community fish.
pH: 6.0 – 8.0
dKH: 5 – 20
Temp: 65 – 77 F (18 – 25 C)
Size: 1.5 – 2″ (4 – 5 cm)
Temperament: Peaceful and active
Swimming: Top to midwater shoaling
Buenos Aires Tetra (Hyphessobrycon anisitsi)
Buenos Aires tetras have a reputation for being a bit nippy when kept in smaller numbers. Stocking them somewhere in the 8 or more region usually solves this issue. They’re active, outgoing, and hardy tetras that can handle a wide range of water conditions.
pH: 5.5 – 8.5
dKH: 1 – 20
Temp: 61 – 83 F (16 – 27 C)
Size: 2 – 2.5″ (5 – 6 cm)
Temperament: Active and outgoing
Swimming: Top to midwater shoaling
Corydora (Corydora sp.)
While each species will vary slightly, all require smooth substrates or bare bottom and do best when they’re kept in groups of at least six or more.
Some larger options would be better here, anywhere from 2.5″ (6.5 cm) and up. Good candidates would include bronze, emerald, Sterbai’s, and peppered cories.
pH: 5.5 – 7.0 – species dependent
dKH: 3 – 10
Temp: 72 – 80 F (22 – 26 C) – species dependent
Size: 1 – 3.5″ (2.5 – 9 cm) – species dependent
Temperament: Peaceful, can be boisterous for less active species
Swimming: Bottom (most) in a shoal of 6 or more
Ghost Shrimp (Palaemonetes paludosus)
Ghost shrimp are usually sold at pet stores as feeders, but they can make great tank inhabitants too! They generally do best in groups of 8 or more and do well with larger fish that won’t eat them. Some very small fish might be eaten by them.
pH: 6.5 – 8.0
dKH: 5 – 10
Temp: 70 – 80 F (22 – 26 C)
Size: 1.5″ (4 cm)
Temperament: Peaceful and active
Swimming: Bottom & structured surfaces
Amano Shrimp (Caridina Multidentata)
Most amano shrimp are wild-caught, so you’ll want to make sure you quarantine them properly before adding them to your tank, but they make peaceful and entertaining algae control crew. They’ll be at their best if they’re kept in groups of six or more.
pH: 6.5 – 7.9
dKH: 1 – 6
Temp: 65 – 76 F (18 – 24 C)
Size: 3″+ (7.5+ cm)
Temperament: Peaceful and active
Swimming: Bottom & structured surfaces
Japanese Rice Fish (Oryzias latipes)
A bit challenging to find, but insanely easy to keep, Japanese rice fish can handle a wide variety of temperatures and make a fantastic beginner fish! It’s best to keep them in shoals of 8 or more.
pH: 6.5 – 8.0
dKH: 9 – 19
Temp: 64 – 75 F (17 – 23 C)
Size: 1.6″ (4 cm)
Temperament: Peaceful and active
Swimming: Mid to top
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.
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.
“Normal” Paradise Fish
M. opercularis naturally have a greenish-blue body with red stripes on their body (the reverse is usually line bred.) Their head is typically lightly patterned with black lines and a black dot on their gill plate. Their tail doesn’t have the webbing in the middle and naturally has a “U” shape.
Blue Paradise Fish
Although not technically a type, some people have bred M. opercularis to be more blue and less patterned than their naturally-colored counterparts.
Albino Paradise Fish
Also usually a color mutation for M. opercularis, they can have varying degrees of blue and red within the fins, but the body color is white and their eyes are red.
Chinese Paradise Fish
A totally different – but related – species (M. ocellatus) is often sold as the “roundtail” or “Chinese” paradise fish. They don’t usually come in color morphs and are a bit more picky with food.
Black Paradise Fish
Also a different, but related, species that goes by “black” or “spiketail” paradise fish (M. spechti.) They’re much more challenging to find and usually can only be special ordered. Much like the Chinese paradise fish, they’re a bit pickier with food and don’t usually come in color morphs.
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