How to distinguish female from male swordtail

Look at the tail fin. In males, usually on the tail is "sword", i.e., the lower beam is significantly extended, the females shorter than the rays.

Pay attention to the shape of the fin at the end of the abdomen, so-called, anal fin. In males it is extruded into a tube of unusual shape - gonopodia. Using this tube, the male fertilizes the eggs in the abdomen of females. Females have the same anal fin has a rounded shape.

The result of crossing various forms of pechili steel sword of different colors – green, gold, black, red. Do not try to distinguish the gender of these fish in color. The fact that the females and males of the sword are colored the same.

Look closely at the fish. The female, ready to bring the fry, at the end of the abdomen appears a noticeable dark spot, and the abdomen becomes big and round. By the way, the sword belong to the viviparous fishes, and their females can fry even when kept separately with no males. The male is sufficient to inseminate a female only once, and it will bring fry two or three times a year. So be prepared for constant removal of offspring.

If you are serious about breeding fish-swordtails, you should know that the formation of the sex of these fish occurs in two stages. At the age of about four months among the fish forming the first medium-sized males. After some time most of the females can also turn into males, surprisingly, some of them may be females that had already spawned. These males generally get much larger.