The paradise fish (lat. Macropodus opercularis) is undemanding, but blusterous and it can attack its tank mates. This small, but very good looking fish has played a role of paramount importance in popularization of aquarium husbandry all over the world. Paradise fish was one of the first species that were brought to Europe, only goldfishes were the ones that came ahead of it.
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Habitat in the wild
The paradise fish, scientifically known as Macropodus opercularis, belongs to the family Osphronemidae. This family is also commonly referred to as the “gourami family.” The Osphronemidae family is a diverse group of freshwater fish that includes various species of gouramis and other labyrinth fish.
The family Osphronemidae includes several other well-known species, such as the dwarf gourami (Trichogaster lalius), kissing gourami (Helostoma temminkii), and pearl gourami (Trichopodus leerii), among others. These fish are characterized by the presence of a specialized organ called the labyrinth organ, which allows them to breathe air from the water’s surface, in addition to using their gills to extract oxygen.
The paradise fish got its Latin name due to the elongated shape of its anal fin, which for some reason resembled a leg to Carl Linnaeus. From Greek ‘μακρός’ means ‘long’ and ‘ποδός’ means ‘a leg’.
The fish originates from South-East Asia. Nowadays it is bred outside its natural habitat. This fish dwells in small waters, drains, paddy fields. Paradise fish areal stretches from Vietnam to Korea, it lives is bogs, paddy fields and shallow lakes coastline. The species especially those from South areas of its habitat are well adapted to living in cold water up to +15 °C; they are not demanding in terms of food and water quality.
The paradise fish eats everything it can swallow, but prefers protein food: insects larvae, worms, small fishes, various spineless species.
Paradise gourami is one of the first tank fishes that were brought to Europe in the second part of XIX century. In 1869 a French officer came to Paris from a Chinese town on a military ship and brought some exotic fish that didn’t look like any of goldfish species.
These were well known nowadays species. The fish made Pierre Carbonnier, a French natural scientist very interested. He was the one who succeeded to breed the paradise fish. This, in fact, was the beginning of tropic fishes breeding in tanks. Biological peculiarities, behavior and the breeding process impressed the scientist. The fish builds a nest from bubbles that floats on water surface, put eggs there and what is the most surprising – the male takes care of the offspring like a babysitter!
The news made lots of nature lovers interested. Paris of that time was excited. The easy process of the breeding gave the chance to organize profitable trade business.
Description
Size
The paradise fish size is up to 10 cm (4 inches) long. In aquarium typically reaches a size of about 2.5 to 3 inches (approximately 6.4 to 7.6 centimeters) in length. However, there can be some variation in size based on factors such as genetics, diet, and environmental conditions. Males and females may also have slightly different sizes, with males often being slightly larger and more colorful than females. As with most fish, providing a healthy and well-maintained aquarium environment can contribute to the fish reaching its full potential size.
Lifespan
In captivity, the average lifespan of paradise fish (Macropodus opercularis) is typically around 3 to 5 years. However, with excellent care and a healthy environment, some individuals have been known to live for up to 7 years or even slightly longer. Like all living creatures, the lifespan of paradise fish can vary depending on factors such as genetics, diet, water quality, stress levels, and overall care provided by the aquarium keeper.
Body
Body is very flattened from sides, as those of the majority of climbing perches species. Dorsal, anal and tail fins are well developed and the male have them elongated and they turn into filamentary outgrowths at the end.
The body coloring is brownish or greenish-brown with red and green stripes over the body that come in turns. The dorsal and anal fins are blueish with red filamentary outgrowths; tail fin is red colored. The coloring becomes more intense as the water temperature rises and during the mating season.
| Characteristic | Description |
|---|---|
| Scientific Name | Macropodus opercularis |
| Common Name | Paradise Fish, paradise gourami |
| Family | Osphronemidae (Gourami family) |
| Origin | East Asia (China, Taiwan, Vietnam) |
| Size | Up to 3 inches (7.5 cm) in length |
| Lifespan | Typically 3 to 5 years in captivity |
| Temperament | Generally aggressive, especially towards its own kind |
| Habitat | Freshwater ponds, slow-moving waters, and marshes |
| Tank Size | At least 20 gallons for a single fish |
| Water Parameters | Temperature: 72°F to 82°F (22°C to 28°C) |
| pH: 6.0 to 8.0 | |
| Hardness: Soft to moderately hard | |
| Diet | Omnivorous, eats small insects, crustaceans, and plants |
| Coloration | Vibrant colors, typically blue, red, and orange |
| Labyrinth Organ | Possesses a labyrinth organ to breathe air from the surface |
| Breeding Behavior | Builds bubble nests on the water’s surface for spawning |
| Compatibility | Best kept alone or with other large, robust species |
| Avoid keeping with small or timid tankmates | |
| Care Difficulty | Moderate to experienced aquarium keepers |
Difficulties in keeping
They are famous for their complete unpretentiousness in terms of a tank volume, water temperature, feeding, water chemical composition. The paradise fish gets on quite well with equally sized tank mates, but keep in mind that the males will fight with each other till death. Therefore, it’s better to keep either just one paradise fish male or a male and a female, but there should be shelters for her in a tank.
Except the above mentioned fish also cleans and protects the tank and its dwellers. In a several days the fish can save the tank dwellers from hydra and planarian.
Hydra is brought into a tank together with food from the natural waters and it attacks both juveniles and adult species. To get rid of hydra you have to put hungry paradise fish into a tank without its dwellers.
Care and keeping in a tank
Tank size
For a single paradise fish, a minimum tank size of 20 gallons (75 liters) is recommended. This size provides enough space for the fish to swim around comfortably and establish territories. However, it’s always better to go for a larger tank if possible, as it will offer more swimming space and allow you to add some tank mates or decorations without overcrowding.
If you plan to keep more than one paradise fish in the same tank, you should provide additional space to accommodate their territorial behavior and potential aggression towards each other. In such cases, a tank size of 30 gallons (113 liters) or larger is recommended to minimize aggression and provide enough territory for each fish.
Keep in mind that the tank size recommendations are based on the specific needs of paradise fish and their aggressive tendencies. Providing a larger tank with ample hiding spots and decorations can help create a more stable and harmonious environment for your paradise fish and any potential tank mates you may introduce. Always remember to maintain good water quality and perform regular water changes to ensure the health and well-being of your fish.
How many paradise fish in a tank?
The number of paradise fish that can be kept in a tank depends on the tank’s size, filtration capacity, and the fish’s temperament. Paradise fish can be territorial and somewhat aggressive, especially towards their own kind and similar-looking fish. Therefore, it’s essential to consider the following factors when determining how many paradise fish to keep in a tank:
- Tank Size: A single paradise fish can be kept in a tank of at least 20 gallons. If you plan to keep multiple paradise fish, you’ll need a larger tank to accommodate their territorial nature and minimize aggression. A 30-gallon tank or larger would be more suitable for multiple paradise fish.
- Number of Males: Male paradise fish are particularly aggressive towards each other. It’s generally best to keep only one male in a tank to prevent fighting and stress. If you wish to keep more than one male, you should have ample space (e.g., 50 gallons or more) and plenty of hiding spots to establish territories.
- Male-Female Ratio: If you plan to keep multiple paradise fish, a suitable ratio is typically one male with two or three females. This helps disperse the male’s attention and reduces the likelihood of constant aggression between males.
- Compatibility with Other Species: Consider the tank mates you want to keep with the paradise fish. Choose peaceful and non-aggressive fish that can handle the paradise fish’s temperament. Avoid keeping them with slow-moving or long-finned species that may become targets of aggression.
It’s important to closely monitor the behavior of the paradise fish when introducing new individuals or rearranging the tank. If any fish show signs of excessive aggression or stress, they may need to be separated or rehomed to prevent injuries and ensure the well-being of all the inhabitants.
Always strive to provide ample hiding spots and visual barriers in the aquarium to create separate territories and reduce confrontations among the fish. A well-planned and appropriately sized tank with suitable tank mates will lead to a more harmonious and enjoyable aquarium experience.
Water parameters
Paradise fish is extremely enduring and it adapts to various environmental conditions. Its distinctive features (eats all types of food, stands various water quality and is immune to many infections) explain why the fish is so popular among beginning aquarists.
Optimal water parameters:
- Temperature: 72°F to 82°F (22°C to 28°C)
- Paradise gouramis prefer a tropical environment with temperatures within this range. Maintaining stable water temperatures is essential to avoid stressing the fish.
- pH: 6.0 to 8.0
- Paradise gouramis can tolerate a wide range of pH levels, but ideally, the water should be slightly acidic to slightly alkaline. Keeping the pH stable is crucial to prevent fluctuations that could harm the fish.
- Hardness: Soft to moderately hard
- These fish can adapt to a variety of water hardness levels, but it’s best to keep the water moderately soft to moderately hard. Aim for a general hardness (GH) of 4 to 15 dGH and a carbonate hardness (KH) of 4 to 10 dKH.
- Ammonia, Nitrite, and Nitrate: 0 ppm
- Ammonia and nitrite should always be kept at zero, as they are toxic to fish. Nitrate levels should be kept as low as possible, ideally below 20 ppm. Regular water changes are essential for maintaining good water quality.
- Filtration and Aeration:
- Adequate filtration and aeration are vital for maintaining water quality and providing oxygenation. Since paradise gouramis possess a labyrinth organ and can breathe air from the water’s surface, good surface agitation is beneficial. The filter should be a powerful one, but at that it shouldn’t create excessive water flow. The fish doesn’t like when there is a strong water flow in a tank. It makes the fish stressed and exhausts it.
Tank decor
As for the tank decorations you should stick to the rule – one shelter for one female and male. Each species has its own territory in the wild and they guard it. So, if there are two paradise fish in a tank, put two similar shelters in the opposite sides of the tank.
Put some coarse leaved and strong tank plants next to the shelters; floating plants will do as well. It is recommend to use dark colored substrate for the tank bottom since it forms a contrast to the coloring and due to this it looks more appealing.
Diet
The paradise fish is omnivorous in the wild and obviously prefers protein food to plant one. In the wild, their diet consists of a variety of small insects, crustaceans, zooplankton, and plant matter. In captivity, it’s essential to replicate this balanced diet to keep them healthy and thriving.
Here are some recommended foods for the diet of paradise fish:
- High-Quality Pellets or Flakes: Commercially prepared fish pellets or flakes specifically formulated for tropical fish can serve as the staple food for paradise fish. Look for products that offer a good balance of proteins, fats, and essential nutrients.
- Frozen or Live Foods: Paradise fish will greatly benefit from occasional feedings of live or frozen foods. Brine shrimp, bloodworms, daphnia, and small insects are excellent choices. These foods provide essential nutrients and mimic their natural diet. Live and frozen food is a perfect choice. Bloodworm, tubefix – the fish will eat both. However, the fish tends to gluttony and it’s better to feed it twice a day with small portions of food.
- Micropellets or Powder Foods: If you have juvenile or very small paradise fish, consider providing micropellets or powdered foods to ensure they can eat appropriately sized meals.
It’s crucial to provide a varied diet to meet all their nutritional needs. Feed them small portions multiple times a day, rather than one large feeding, to mimic their natural feeding behavior and prevent overeating. Overfeeding can lead to water quality issues and health problems.
As with any fish, remember to remove any uneaten food from the tank after a few minutes to maintain good water quality. Observing your paradise fish’s behavior and appetite will help you gauge the right amount and type of food they need for a balanced and healthy diet.
Tank mates
This is quite aggressive kind, first of all it is true about the male species. Therefore, choosing tank mates is quite a difficult task. Many males are very aggressive towards each other and other fishes as well, that’s why it’s better to keep just one couple and put large sized tank mates into the volume.
The best idea is to keep paradise fish in a species tank, where only representative of its kind live, at that there should be one male and one or several females. The paradise fish males are extremely aggressive towards each other, they fight for the territory and hurt each other.
It is especially not recommended to keep goldfishes, angelfishes and discus fish in one tank with paradise fish as well as small fishes like neon tetra, guppies at others. It is a skilled hunter, so any juveniles won’t survive in one tank with it.
Here are some suitable tank mates that can coexist peacefully with paradise fish:
- Harlequin Rasboras (Trigonostigma heteromorpha)
- Neon Tetras (Paracheirodon innesi)
- Ember Tetras (Hyphessobrycon amandae)
- Glowlight Tetras (Hemigrammus erythrozonus)
- Black Neon Tetras (Hyphessobrycon herbertaxelrodi)
- Cardinal Tetras (Paracheirodon axelrodi)
- Rummy Nose Tetras (Hemigrammus rhodostomus)
- Dwarf Gouramis (Trichogaster lalius or Trichogaster chuna)
- Sparkling Gouramis (Trichopsis pumila)
- Celestial Pearl Danios (Danio margaritatus)
- White Cloud Mountain Minnows (Tanichthys albonubes)
- Dwarf Rasboras (Boraras spp.)
- Endler’s Livebearers (Poecilia wingei)
- Guppies (Poecilia reticulata)
- Platies (Xiphophorus spp.)
- Corydoras Catfish (Corydoras spp. – pygmy cory, panda cory, adolfoi catfish)
- Otocinclus Catfish (Otocinclus spp.)
- Bristlenose Plecos (Ancistrus spp.)
Gender differences: male vs female
Male and female paradise fish can be differentiated by several physical and behavioral characteristics. Here are some of the key differences between male and female paradise fish:
- Size: In general, male paradise fish are slightly larger than females. Males may grow up to 3 inches (7.5 cm) in length, while females are usually a bit smaller, reaching about 2.5 inches (6.3 cm).
- Coloration: Male paradise fish tend to have more vibrant and intense colors compared to females. They often display a beautiful combination of blue, red, orange, and iridescent shades on their bodies and fins. Females typically have less intense colors, and their bodies may appear more subdued.
- Fins: The fins of male paradise fish are more elongated and pronounced, especially the dorsal and anal fins. These fins may have extended rays, making them look more showy and ornate. Female fins, on the other hand, are generally shorter and less elaborate.
- Behavior: Male paradise fish are known for their territorial and aggressive behavior, particularly towards other males and similar-looking fish. They can be seen flaring their fins and engaging in displays to establish dominance and attract females. Females are usually less aggressive and more peaceful, although they can still exhibit some territorial behavior, especially during breeding.
- Ovipositor: Females possess an ovipositor, a small tube-like structure located near their vent. The ovipositor is used during spawning to release and deposit eggs. Males lack this structure.
It’s important to note that while these differences can be used as general guidelines, there can be variations among individual fish and different populations. If you have multiple paradise fish in your aquarium and want to determine their genders, observing their behavior and examining their physical characteristics can help you differentiate between males and females.
Breeding
Breeding is quite simple, however the male makes the process more difficult. While building a nest and spawning it becomes very aggressive towards the female, so shelters could not have come at a better time in this case.
The older the male is the more aggressive it becomes and very often it kills the female.
You can breed paradise fish in small volumes. Floating hornwort or other floating tank plants can be used and spawning substrate.
Adult reproductive species should be put into separate volumes several days before spawning. When you put the paradise fish ready to spawn into a spawning tank, they start getting interested with each other right away.
A small tank can be used as a spawning one. It should be filled to 3/4 full with water from the old tank plus 1/4 of new soft water.
The water level should be 7—15 cm for small species and 20 cm — for large ones. Make a shelter for the female from small leaved plants.
When everything is ready put the couple into the spawning tank and rise the water temperature by 2-3 °C.
The male always initiates the spawning process. Some time later it starts building a floating nest from bubbles, where the fish will put eggs. There the eggs will have the most favorable conditions, because the eggs need a lot of oxygen for proper development.
There are some recorded cases when the male builds a nest not on the water surface, but in hollows of tree roots, where the nest is sheltered with something from above and it doesn’t float on the water surface.
When the paradise fish finishes building the nest, the male stops warding off the female and vise versa starts to attract her and wants her to get inside by performing kind of a ritual dance.
The female that is ready to spawn must have a rounded abdomen filled with eggs. The spawning process starts when the female swims to the nest near which the male swims. During the spawning the fishes hold each other for a moment and squeeze eggs and milt. Then the eggs go up to the tank water surface.
The male quickly gathers them into its mouth and brings them to the nest. This can be done lots of times till the female lays all the eggs.
After each spawning the female must have a chance to hide among the tank plants to have some rest. If she doesn’t have this chance, the male can even kill her. That’s why when the spawning is over, take the female out of the spawning tank.
The paradise fish male takes care of the eggs. In about four days after the spawning remove the male from the tank as well. If you don’t do this, it may eat almost all its offspring.
It happens sometimes, that the male doesn’t demonstrate any parental instinct or the conditions aren’t favorable for this and it leaves the nest and eats the eggs. Such a male should be removed from the tank immediately.
The eggs will grow on their own. To make sure that they won’t get any fungus infection, add 2-3 drops of 1% methylthioninium chloride solution per one liter of water into the tank.
Small paradise fish larvae will hatch from the eggs in 1-2 days after spawning and they will stay under the nest. What is interesting, is that the nest helps the juveniles to feed during the first days of their lives.
Parts of plants, saliva that contains proteins by this time loose all its germicidal properties and start to rot. Therefore, lots of infusorian, rotifer, small worms and then crustaceans appear under the nest.
The same gathering of small organisms can be found among the roots of floating tank plants. Once the juveniles start to swim and feed, remove the male from the tank.
In 8-12 days since the day when the juveniles start to feed themselves you should add cyclops into their diet. It has to be rather diversified and the amount of food should be sufficient, so that the juveniles swim among the food. Each two days renew 2/3 of the tank water with the fresh one.
A lung-like labyrinth organ starts helping the juveniles to breathe only in 3-5 weeks after their birth. When the juveniles breathe only using their gills the water level in tank should be low and it should be blown trough with air all the time.
You can’t decrease the water temperature at this time. The juveniles behavior will show you that they are already breathing with their labyrinth organ as well. They will regularly swim up to the water surface and gasp the air.
Now you can raise the water level in a tank and gradually, by 1—2 °C in a week decrease the water temperature.
If you meet all the above mentioned requirements, paradise fish juveniles will grow fast and at the age of several month old they will have the same coloring as the adults have.
If the juveniles grow with a different rate, small ones can be eaten by the large juveniles. You can avoid this by sorting the juveniles according to their size.
Small climbing perches species become reproductive at the age of 7-8 months and the larger ones a bit later.