Swordtail

These fishes on its popularity at aquariums successfully vie with guppi. They fine get along also in hard and in the soft water, firmly carry the more or less gradual change of its composition, not bad feel at the ordinary room temperature also, although for their growth and reproduction optimum temperature 22—24 °With.

Characteristic feature of this kind, for which it and got its name, long sharp virost of lower part of tail plavnika — sword incident to males.

This is comparative large fishes. The females achieve 10—12 sm, males some more shallow and stroynee. In the small aquariums mechenostsi, as a rule, do not achieve maximum sizes, but do not thus lose true forms, health and capacity for reproduction. Polovozrelimi they become in age about 6 months. The young females bring on 10—15 fries, the females of senior ages give on 40—50 fries and more. At the desire to save all pomet, transplant the females before metanem, and after births delete from fries. But in the enough capacious aquarium with thick kurtinami of plants and supernatant richchiey part of fries is saved next to the adult fishes also.
Initial form — so-called green swordtail

— is taken out from the south of the American continent. These fishes of silvery-greenish color with the korichnevo-krasnoy bar along the middle of body, bordering a sword of male from above and snizu. By crossing with the coloured forms of petsiliy a number of colour forms or breeds of aquarium mechenostsev is shown out.
Red mechenostsi were got crossing of initial form with red petsiliey (rubroy, as it was named by the Moscow amateurs). The got hybrids inherited colouring of the coloured form, but males turned out sterile, so that in breeding it had to come running to coupling of hybrid females with males of green mechenostsev. From hybrids and initial form pomesnie mechenostsi among which part were by coloured gave birth, and part, so-called mechenostsi «from under red», differed from the initial form by the only more wide and bright red bar along body. Just the same males went in breeding. Forasmuch as the coloured males had an unclear expressed sexual type, were shirokoteli, as females, differed from them only by the presence of «sword» and form of anal plavnika and did not give posterity. At the further coupling of the coloured females with males «from under red» it succeeded to get and fruitful males of the red colouring. The further selection of red mechenostsev was directed on strengthening of brightness of their colouring, with that to obtain destroying of mechenostsev of scarlet, because originally the aquariums located by the brick-red fishes only. This succeeded to be obtained at the beginning of fiftieth years only. At the use for the receipt of hybrid forms of more bright petsiliy for hybridization the artificial insemination was used with fixing of desired okrasa on the basis of genetic laws about the inheritance of signs.

Black swordtail

at the beginning of fortieth years are got the same method, that and previous form. Only by the initial form at crossing black petsilii served with mechenostsami (shvartsi). A chart of crossing at the receipt of fishes of desired okrasa, including fruitful males of black okrasa, was by the same. Males «from under black» differed from simple mechenostsev and hybrids «from under red» comparatively by the narrow umber bar along body and the same mount of sword. In first post-war years becoming of this interesting variety it had to begin anew, with the use of artificial insemination, that considerably accelerated this work.
This coloured form turned out water more capricious to composition and to the oxygen mode, than red mechenostsi, and the fruitful coloured males remained dream of aquariums during many years. Black mechenostsi and ponine comparatively rarely meet at aquariums. In the decorative aquariums they were pressed by velvety-black mollinezii, so showy, but less whimsical.
Tiger mechenostsi — red with black fishes, are shown out on the basis of hybridization of green mechenostsev with petsiliyami and subsequent crossing with the coloured varieties of mechenostsev before shown out. Besides the described difficulties with the receipt of fruitful fishes of both chaffs, the selectionists ran into another problem. During many generations of fish of this variety, fully normal in the young age, maturing, lost tail plavniki. However the modern aquariums locate by tiger mechenostsami free of this vice. And the selection of these fishes is directed on destroying of more bright mechenostsev with predominance of scarlet tint of red background and with the symmetric location of black spots. Printed cotton mechenostsi combine in its colouring red, black and white colors, that does them especially by the showy decoration of aquarium. They appeared at the beginning of fiftieth years at the Moscow aquariums thanks to labour of the remarkable N.A selectionist. Vasileva, which worked on destroying of a new form of mechenostsev.
Along with the described colour forms in the aquariums of amateurs it is possible to meet the albinos, lemon mechenostsev and most different derivative from accidental metizatsii of initial varieties, as a rule, less interesting, than their parents. At the beginning of fortieth years fashionable novinkoy were been by point mechenostsi which named montazumami. They had symmetric located bars orangevo-krasnie with the bright red points along body. But soon this variety vanished, whether both because was less attractive, than red and tiger mechenostsi, whether or as a result of difficulties of war-time. The last years, along with the colour variety of mechenostsev, the population of aquariums was filled up by the scarf fishes with the lengthened dorsal fins, and also by the vualevoy and vilchatoy forms of mechenostsev of different colors