Life in ponds. Part 1

A great many microscopic creatures - ciliates, rotifers, copepods, water fleas - the fruit and multiplies in the calm water of these lakes. Red mites are floating back and forth, rapidly turning over legs. There are many aquatic insects, which we have partly mentioned above. From mid-May can be seen laying eggs in small leeches klepsiny. This small light-red leeches to 2 cm long. Unlike other leeches klepsina protect their offspring. Testes, it cleaves to the abdomen, which bends in a trough or gutter. In this case, it is so tightly clings to the spot on which sits, that move it from there it is very difficult. In the first half of June, the eggs hatch the young leeches. However, they did not leave his seat and remain under the mother, every now and then leaning out the front ends and back again, hiding (Fig. 87). Only a little later they begin to unravel and to live independently. As adults klepsiny, they cling to the soft parts of various molluscs (Lymnaea stagnalis and coils) and feed them with blood. That is why this is sometimes called the cochlear leech. In late May and early June can be found on the leaves of aquatic plants young colonies of bryozoans - sedentary animals with numerous tentacles around the mouth. At the same time out of the eggs the young snails of the genus Lymnaea stagnalis (Limnaea). Spawn their pond, as well as other aquatic molluscs, attached to the leaves of aquatic plants. In pond it looks like a transparent gelatinous sausage inside of which clearly visible from the testicles. In early June, you can find the eggs and other aquatic snails - Coil (Planorbis) as a reddish, flat and pro-dolshvatyh gelatinous pellets glued to underwater objects and plants. Oviposition of Lymnaea stagnalis and coils continues until the autumn frosts. At the end of May or the beginning of June the departure of some however, the larvae of caddis flies are found throughout the summer. They have a vermiform shape and generally satisfied with his original houses or chehliki, which puts them a long and delicate body. Different types of use for this building a variety of materials: grains of sand, pebbles, shell, fragments of stems, bits of leaves. From these pieces of larva glues long muff or tube, in which the lives, carrying her everywhere, like a snail shell. This tube serves as a good protection for the soft body of the larva. With the growth of larvae build on their front covers since the end of May, these larvae turn into pupae. In late May near the water there are small slow-moving insects in the shape of wings resemble caddis. This so-called viskokrylki.