Paradise fish - Macropodus opercularis
Scientific name: Macropodus opercularis
Common name: Paradise fish
Usual size in fish tanks: 9 - 10 cm (3.54 - 3.94 inch)
Recommended pH range for the species: 6.8 - 8
Recommended water hardness (dGH): 4 - 18°N (71.43 - 321.43ppm)
0°C 32°F30°C 86°F
Recommended temperature: 16 - 26 °C (60.8 - 78.8°F)
The way how these fish reproduce: Spawning
Where the species comes from: East Asia
Temperament to its own species: peaceful
Temperament toward other fish species: aggressive to smaller
Usual place in the tank: Top levels
The Paradise Fish is the one of my favorite ones. Very nice, quite intelligent and quite aggressive. They are also easy to care for, since they adapt easily to the acidic water as well as to the hard water. Pradise Fish’ habitat should contain enough plants, still water and medium lighting.
Don’t keep the Paradise Fish with guppies, since these small fish will be eaten. If you have plenty of guppies, you may consider using them as feeder fish. On the other hand, Paradise Fish are peaceful to the Tetras or other small species. In my opinion, they will eat smaller fish only if they attract them with various colours like guppies do.
Breeding is easy and they breed like Gouramis. They’re building nests and the female lays about 50-200 eggs. The male becomes aggressive towards the female and this is the reason why you should keep them in large tanks. Use 30 litres per 1 fish.
When they’re young, they tend to swim together, but once they reach the adult age, they will separate and will become territorial. Please note, that they’re not territorial or aggressive towards larger fish.
The following answer was moved here from aqua-fish.net/answers due to merging on March 25th 2011.
Why do paradise fish gulp air from the surface?
Answer: Paradise fish are members of the Gourami family; this means that they are labyrinth fish requiring oxygen from the atmosphere as they have primitive lungs.
Picture has been provided by Elektra.