The paradise fish (Macropodus opercularis) is undemanding, but blusterous and it can attack its tankmates. 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.
Habitat in the wild
The Macropodus opercularis 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.
Macropodus opercularis 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 Macropodus opercularis eats everything it can swallow, but prefers protein food: insects larvae, worms, small fishes, various spineless species.
Macropodus opercularis 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 Macropodus opercularis. 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.
The size is up to 10 cm (4 inches) long; females are sufficiently smaller than males. Paradise fish is a long liver among all climbing perches species and provided with favorable tank conditions its lifespan in a tank may be up to 8-10 years.
Though in terms of successful breeding, it is preferable to use the species up to 4 years old.
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.
Difficulties in keeping
They are famous for their complete unpretentiousness in terms of a tank volume, water temperature, feeding, water chemical composition.
The fish gets on quite well with equally sized tankmates, but keep in mind that the males will fight with each other till death.
Therefore, it’s better to keep either just one male or a male and a female, but there should be shelters for her in a tank.
Care and keeping in a tank
|Scientific Name||Macropodus opercularis|
|Common Name||Paradise fish, paradisefish, paradise gourami|
|Tank size||17 gallons and more|
|Temperature||72°F- 78°F (22 to 26 °C)|
|Size||up to 10 cm (4 inches)|
|Lifespan||up to 10 years|
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.
Except the above mentioned Macropodus opercularis 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 Macropodus opercularis into a tank without its dwellers.
One or two fish require a small tank of about 80 liters capacity; it is desirable that it has a cover. You can do without a heater, since the fish feels quite comfortable when the water temperature is 16°C.
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.
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 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.
The fish is omnivorous in the wild and obviously prefers protein food to plant one. It feeds on juveniles and small aquatic insects. In a tank you can feed with artificial food, though the diet should be diversified and not limited just to some branded food.
Live and frozen food is a perfect choice for a Macropodus opercularis. 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.
This is quite aggressive kind, first of all it is true about the male species. Therefore, choosing tankmates 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 Macropodus opercularis couple and put large sized tankmates 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 males are extremely aggressive towards each other, they fight for the territory and hurt each other.
Macropodus opercularis is a skilled hunter, so any juveniles won’t survive in one tank with it.
The males are noticeably larger than females; they have larger fins, brighter and more saturated coloring.
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 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 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 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 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 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, 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.