Keeping and breeding Paradise fish
The first important thing when you want to keep paradise fish is that the fish show parental care. They make a bubble nest and defend it fiercely. During the breeding season these fish are therefore aggressive, especially, but not exclusively, toward conspecifics. Another point is that these fish mainly occur in areas with seasonal changes (this applies to a much lesser extent to the black and the Red-backed paradise fish). If we take that into account, the Paradise fish can be kept very well in a community aquarium.
First let’s look at what seasonal changes should mean for the aquarium climate. We base this on the most common Paradise fish, Macropodus opercularis. A species of a subtropical to marginally tropical climate, partly in mountainous areas.
Ideal for this species is an unheated living-room aquarium (in fact an unheated room is already sufficient). Cooler in winter, while in summer the temperature can rise high in warm weather.
This way the animal is not artificially kept in breeding condition all year round. Due to the lower temperatures the fish are also not overly active or aggressive. In such an aquarium the paradise fish can be joined by a barbel that also has low temperature demands, such as Pethia splendida (prachtbarbeel), Danio dangila (ticto) or Pethia nigrofasciata (purperkop). You will be surprised how pleasant these barbs are as aquarium inhabitants when they are not kept at unnaturally high temperatures. Many danio species are also suitable.
Next we must take into account the territorial drive of paradise fish during the breeding period. We must ensure that the territory of these fish, when they have a bubble nest, remains as small as possible. We achieve this by making sure the tank is not fully visible to the fish. The easiest way to realize that is by using plenty of driftwood. If there are also enough floating plants present the paradise fish will certainly be comfortable and will show their natural behavior.
In a tank of just over a meter we can without problems keep two pairs of paradise fish together with a school of barbs and/or danios. If the tank is obscure enough you could keep a maximum of three pairs in such a tank. More is pointless. Unlike schooling fish, we will not enjoy these fish more if the number kept is larger. In a smaller tank of say 80 cm length it is better to keep only one pair of paradise fish, optionally together with a small group of barbs or danios.
What has been written so far about keeping the common Paradise fish largely also applies to the Black Paradise fish. This species is tropical, but originates from mountainous areas. We can keep this animal year-round at the same temperature. It is then important not to keep the temperature permanently too high. With an upper limit of 25C and a lower limit of 18-20C we have a pleasant and attractive aquarium inhabitant.
The Hong Kong paradise fish and the Red-backed paradise fish are considerably more aggressive than the other species. A single pair in a spacious tank that is not kept too warm will, however, not cause major problems.
Breeding paradise fish
It is often written that breeding paradise fish is easy. That is true insofar as most species readily build nests and spawn. The eggs also hatch after a short time. For an experienced fish breeder raising the fry is not difficult. But that is where the first difficulty begins: raising young fish is not easy!
First the basic recipe and then the difficulties listed.
Basic recipe
Place a pair in a breeding tank of at least 60 liters (experienced breeders who know exactly when to intervene can use a 25-liter tank for some species). Water depth does not have to be particularly low. A water depth of 50 cm works just as well. Water composition is not very exacting. Not too hard and a pH around 7. Temperature not too high. 23-24C is fine. At higher temperatures the fish are more aggressive.
The species is a bubble-nest builder and therefore defends its nest. Usually the male allows other fish than his own species fairly close to the nest. The male defends the nest and the female the area around the nest. In a large tank the female therefore has nothing to fear. In a small tank the female comes too close to the nest after spawning and is chased away. It is therefore best to remove the female after spawning. In any case it is important to provide many hiding places. The male is removed when the fry are two to three days old.
Another option is to scoop the nest with fry (or with eggs) out of the aquarium. Then you can also breed this species from a community tank. Raise part of the usually large nest and that’s it.
The difficulties listed
- The male is aggressive during the spawning period and the female risks being killed. What to do to prevent this has already been described: not too small a tank, many hiding places and not too high a temperature.
- The fry are very small and there are so many of them.
You only start feeding when the fry are free-swimming. The fry are so small that they need infusoria for at least a week. Paramecia are very suitable. You will need to culture those yourself. You can also squeeze algal mats from a clean ditch and use that water. That is full of infusoria. After about a week or slightly longer you can start feeding Artemia nauplii and micro worms. Possibly some very finely ground dry food.
- Extreme hygiene is necessary. Therefore do not keep too many fry. You can feed the surplus to the other fish. It is best to use a plastic container of several liters and change three-quarters of the water daily or twice a day (same temperature and composition). Feed at least four times a day a small amount. This period is the most difficult and often fails if you want to raise a brood for the first time.
- When the labyrinth organ forms the fish are vulnerable.
The labyrinth organ is formed, depending on growth rate, around three to four weeks. Provide a cover. Dry air above the water is fatal and will cause many victims. With sufficiently humid air above the tank it is not a problem. At a certain point you will see the fry regularly gulping air. After a week the vulnerable period is over. Then place the animals in a larger tank. They will now grow quickly and rearing is no longer difficult.
Photo copyrights
Hristo Hristov
Hung You Chen
John de Lange
