Very valuable animals are mizidy , reminding shrimps. They concern group of the higher Crustacea. Length of their body usually 10 35 mm. They filter water, eat the same forage, as bokoplavy. At the moment of fertilisation the female postpones in vyvodkovuju a bag to 150 and more eggs. The period of reproduction since early spring and till late autumn. In this time one steam mizid can breed to 400 and more thousand copies. Vynashivanie eggs, depending on a kind, conditions (especially from temperature) lasts from several days about several months.
Mizidy are a highly nourishing product. Fat in their body contains from 9 to 14, fibers - from 64 to 74, carbohydrates - from 5 to 12 percent. Thanking their special fodder value they last years became one of the most popular gidrobiontov, used for introduction in various rybhoznye reservoirs for the purpose of increase of natural fodder stocks. Mizid in industrial conditions plant in trays, pools, mesh corfs.
Colouring mizid at the same kind happens at various times and in different conditions various. Emerging at night to a surface, mizidy become transparent, in thickets of plants they get their colour, among stones - yellow-grey, on an oozy ground - dark grey. Winter mizidy in deep places, and master a coastal zone where them and catch melkojacheistymi trawls, nets in the summer.
And now we will get acquainted with dafnijami . The Most widespread are - dafnija big, dlinnohvostaja and kukuljata. Length dafnii big, for example, 2-2,6 mm, the male - 1,6-2 mm. The sizes of others dafny - slightly less. They live in any reservoirs on well warmed up places, eat a phytoplankton. Within days one dafnija filters to 300 thousand cages hlorelly. A sexual maturity dafnija reaches for the third-fifth day of a life. Lives at temperature plus 28°С no more than 26 days, with fall of temperature life expectancy increases. At temperature about zero lives till 180 and more days. Fruitfulness of a female makes approximately 140 eggs, for a life has time to give 25 and more dung. Dafnija big is an active absorber of radioactive substances. From the practical point of view dafnija it is interesting first of all as the richest forage to fishes.
A Cyclops concerns the following big group veslonogih rachkov . Their length on the average: females - 0,8 1,5, the male - 0,6-0,8 mm. In the majority it is gluttonous predators, it is active as alone, and groups attacking on similar and even on larger individuals - larvae hironomid, oligohet. At an attack the hvatatelnymi bodies kill and break off a victim. Eat also the elementary, detrit and phytoplankton components. A Cyclops, as well as other Crustacea, are a valuable forage for fishes. However a Cyclops, being active hvatateljami, attack layings of caviar and a larva of fishes.
Great value in a food of fishes, other water organisms have kolovratki - one of the smallest rachkov. Kolovratki, as well as many other things gidrobionty, play the important role in natural self-cleaning of reservoirs and improvement of quality of water, are indicators organic and other kinds of pollution, salinity, acidity, active reaction of environment etc. kolovratok, nowadays known to a science, it is a lot of forms. Now kolovratki industrial kultivirovanija their technology is well studied, developed for maintenance malkov fishes by a starting forage.