Carefully look into your charges. Some of the fish sexual dimorphism is very clear and to distinguish the boys from the girls here will not be easy. However, if you have no idea what different ladies from the Cavaliers, the internal differences of the fish, though you will noticeable, but no information is give. When breeding guppies many people think that males from females to distinguish not so simple. This is a misconception. Look closely at the anal fin fish. If he pointed in front of you boy, if scroogle – you consider a girl. On this basis, by the way, you can determine the sex of the fish before the onset of their puberty, when the addition of the anal fin the males and females does not differ. When fish grow, a characteristic feature of the boys becomes a beautiful colorful tail and dorsal fin. Females, on the contrary, remain inconspicuous and gray, the tail fins are much shorter and not as bright.
Pay attention to the shape of the anal fin. Not all aquarium fish difference of the sexes, significantly so. The relatives of guppies mollies no bright tails, no spots. Both males and female have a uniform black color and similar to each other, almost like two drops of water. Here to help you observation and watchful eyes. Mollies also differ in the anal fins. In females they are rounded, while males have a pronounced pikeminnow form. Some varieties of mollies and all are holders of an elongated and slightly folded anal fin, so boy it is possible to always allocate from the crowd.
Look at the size of the fish. Often females are slightly larger than males, and in some species this difference is quite noticeable. Of course, no one size is not necessary to navigate, because pet stores often sell fish from different litters. It is therefore necessary to pay attention to other symptoms. From neons, for example, the stripes on the abdomen of females has a small fracture, slightly curving in the middle. Males are the owners of a perfectly straight back, and the stripes on their body parallel to the horizon. If you decide to separate the males from the females in the pack Danio – also note the size and arrangement of the strips. Females are larger, and the stripes on the abdomen they have a little wavy. Males have a more slender figure and smooth strips.
Before you go for fish in a pet shop or on the market, review the professional literature and get at least a rough knowledge about the differences of the sexes. Unfortunately, often the sellers are cheating gullible buyers by selling them the fish of the same sex.
Have live-bearing fish, females are already in the store may have an enlarged abdomen, which are easy to distinguish from males.