How to Tell the Male From the Female Pearl Gourami

You can readily identify male pearl gouramis by their coloration. Males are always more colorful than their female counterparts. This is true across this family of fish, which includes the betta and the paradise fish. When breeding season nears -- in the home aquarium this could just mean a temperature change or better food -- males get even more colorful. Males pearl gouramis in breeding condition develop a splash of a stunning red or orange color on their throats to attract mates.

You can also tell a male pearl gourami from a female by the shape of their fins. Males generally have longer and larger fins that their female counterparts. Additionally, the fins have a more angular, pointed shape on males. The dorsal and anal fins have extensions that grow off the tips of the dorsal and anal fins. These make pearl gouramis -- and gouramis in general -- magnets for fin-nipping fish.

In addition to having differently shaped fins, male and female pearl gouramis have slightly different body shapes. Females have more rounded and heavyset bodies. Meanwhile, males are thinner. Male pearl gouramis also have more angular bodies, straighter lines instead of curves. This difference is subtle and may take some practice to master.

You can tell your fishes' sex by their behavior. Males tend to be more aggressive than females. Male pearl gouramis' aggression is not as pronounced as it is in some members of this family. However, males may occasionally chase other fish around the aquarium. In particular, males may fight amongst themselves. When these fish decide to breed, males will construct nests made out of bubbles and plant bits. Only the males of the species do this. So if you see a fish blowing bubbles into the corner of your aquarium, you know it's a male.