Many say that goldfish are the first-ever pet fish as there are records dating back 500 to 2,000 years. However, when you are talking about the first species of fish displayed in aquariums, circa the mid-1800s, paradise fish were the vicious beauties that made the tropical freshwater fish-keeping hobby catch on and take hold as a popular pastime. This fish is still among the most glamorous-looking but nasty-acting of all species found in the freshwater aquarium hobby.
Common Names: Blue paradise fish, paradise gourami, blue paradise gourami
Scientific Name: Macropodus opercularis
Adult Size: 4 inches
Life Expectancy: 6 to 8 years
|Tank Level||All areas|
|Minimum Tank Size||20 gallon|
|Breeding||Bubble nest breeder|
|pH||5.8 to 8.0|
|Hardness||5 to 30 dGH|
|Temperature||61 to 79 F|
Origin and Distribution
This paradise fish is found across a considerably wide range of southeast Asia. In China, it is found from the east in the Yangtze River basin to the Pearl River basin, in Hong Kong, and on Hainan Island. It also occurs in Taiwan, northern and central Vietnam, northeastern Laos, Cambodia, Malaysia, Japan, the Ryukyu Islands, and Korea. It has also been introduced outside of its native range, with populations also found in Madagascar and the United States.
There has been much debate and much written, in both scientific and hobby journals. The controversy revolves around whether or not the fish in the hobbyist tanks today is still the same species as the one that exists in the wild; the wild viability of the captive-bred fish remains a question. Though data is inconclusive, it seems that the common variety of the fish we know in tanks today is much the same as the fish that swims in the rice fields in Asia.
Colors and Markings
Three separate species are all referred to collectively as the paradise fish that are commonly kept in the home aquarium. They look very similar to each other but are distinguishable by the shapes of their tails. Macropodus opercularis has a forked tail; Macropodus chinensis has a rounded tail; and Macropodus cupanus has a pointed tail with several rays extending from its middle.
All three species are banded with stripes of vivid color, which appear different according to the angle of the light falling upon it. These bands are blue or green alternating with orange or red. There are also numerous small dots of black or metallic blue scattered over the body of the fish. In all three species, the ventral fins are always orange.
In captivity, there are two genetically engineered varieties. There is an albino variety, called the albino macropodus, which was engineered by a commercial breeder in Germany in 1933. It has pink eyes and white, pink, and blue stripes. The other strain is a darker variety called the “concolor” variety.
In a community setting, Macropodus needs to be the dominant species. It should not be kept with other robust fish that may make a challenge, as it will fight with other dominant fish. However, if the others are larger and aggressive Macropodus will hide and often succumb to stress.
Young paradise fish can be kept in groups, but as they mature the males become combative with other males; any smaller male can be attacked. Males generally do not get along together unless the tank is very large with lots of decor for hiding and retreat.
Males that are not kept apart will engage in aggressive combat, locking jaws, and permanently damaging one another. If keeping a small mixed group, it is necessary to keep only one male and female as a pair in their own tank. When females are younger and not territorial, sometimes it is possible to keep a group of females together.
A mix of neutral personality fish that are not similar in body shape is the ideal goal for any possible tank mates. Be careful in selections, and be prepared to adjust companions whenever a change is needed.
Good tankmates can be larger fish such as goldfish as well as non-aggressive medium to large gouramis, robust cyprinid species, larger characins, eartheater type Geophagus cichlids, Loricariid catfish from South America, large Synodontis catfish, and large loaches. Avoid housing them with any slow-swimming fish or fish with long flowing fins.
Paradise fish are not good tank mates with fish their size. In fact, they are downright nasty, ripping at tails and sometimes killing other smaller fish even of their own kind. Similar to bettas in disposition, paradise fish are belligerent and predatory. They prefer to live alone but will accept some other species of fish as long as they are a good deal larger and non-aggressive.
Paradise Fish Habitat and Care
The paradise fish is very adaptable and can adjust to almost any water condition. The size of the aquarium for a juvenile should be at least 20 gallons. On the opposite end of the spectrum, your aquarium can be a 5000-gallon backyard pond full of koi. These fish can handle a wide variety of temperature fluctuations from the weather, but live plants are always a must in any environment housing paradise fish.
Paradise Fish Diet and Feeding
Paradise fish are omnivores that will accept most foods. However, they require a well-balanced diet to remain healthy. In the wild, these predators feed on small fish and small aquatic animals like invertebrates. In a pond, they will greedily eat both mosquito larva and any vegetable matter that happens to fall into the pond.
In an indoor aquarium, feed once or twice a day and feed generously. Algae-based flake foods are essential, in addition to meaty foods. Feed small live foods whenever possible. Supplementation should include white worms, blood worms, and brine shrimp.
Male paradise fish are larger than females and have brighter and stronger color patterns. Their fins are also longer and larger than females. All three species of paradise fish are banded with stripes of vivid color, but all of these stripes are also hormonally intensified in the male during courtship.
Breeding the Paradise Fish
Breeding this species is not difficult. For conditioning breeders, live foods are recommended, as well as high-quality algae-based flake or pellet food. Note that it is important to feed the female heartily and well in advance of attempting to spawn her, as she will refuse food for up to two weeks while she is holding eggs.
Keep the male and female in a separate environment with small offerings of live and frozen foods several times a day. When well-fed, females should begin filling out with eggs, appearing very plump. Females not yet ready for egg-laying should be kept away from breeder males as males have a nasty temperament and may mutilate or even kill their intended females.
Like most fish in the labyrinth fish family, paradise fish are bubble nest builders. The male builds a bubble nest, woos a female, and then defends the nest to the death. Frequently, males build their nests beneath a leaf. After spawning, the female should be removed from the tank or you again risk the female being killed by the male.
To breed paradise fish, place them in a separate breeding tank about 20 gallons in size. It should be set up with the water at a very low level, only about 6 to 8 inches. When the fry have easy access to the air above, the labyrinth organ in the fry can develop normally. Normal water chemistry parameters are fine but raise the temperature to between 80 to 84 degrees Fahrenheit. You can add a small air-powered sponge filter or some peat filtration, but the tank current should be minimal.
Hatching time varies with temperature. Generally, the fry will emerge between 30 and 50 hours, but they can take up to 96 hours. When guarding the nest, the male will not eat. But once he does begin to eat food, the male should be removed as he might eat the fry that emerge from the nest. For the health of the male, leave him in place as a dutiful guard for as long as he requires. This way, his protective hormones will subside naturally; removing him too early will be an unnecessary challenge to his health.
More Pet Fish Species and Further Research
If paradise fish appeal to you, and you are interested in similar fish for your aquarium, check out:
Check out additional fish species profiles for more information on other freshwater fish.