LAKE ISSYK KUL
The most ancient element in the fauna of the lake are the Indian bryozoans Victorella bengalensis, and L. S. Berg clam which, by definition, VA Lindholm, Hydrobia venturosa. This species now common to the coast of the seas surrounding Europe, there is in the Black and Azov seas, but not in the Caspian sea. Berg L. S. (1930) believed that the presence of this mollusk among the nagor-no-Asiatic fauna is the mystery.
The bottom of the bays and backwaters of the Issyk-Kul lake are covered with dense thickets of pondweed, reed, and charophytes. ‘hara thickets on the slopes of the basin of the lake drops to a depth of 30-40 m.
Phytoplankton counts 309 forms. He is poor in the open part of the lake, and significantly richer and more diverse in the coastal zone, where conditions are more varied. Zooplankton of the open lake is also monotonous.
Basically, he presents two types veslonogih Rachkov. It is characteristic of brackish waters Diaptomus salinus and cosmopolitan Cyclops viridis. V. M. Rylov, in the summer of 1928, studied the zooplankton of lake Issyk-Kul, notes that it is similar to the one in lake Baikal and Tanganyika: in the open waters of pet cladocerans.
For Issyk-Kul is characterized by the following representatives of the brackish-water zooplankton: Brachionus backed var. hyphalmyros, Br mulleri, Pedalion oxyure, endemic crustacean copepods Eurytemora composita (according to L. S. Berg, close to the Arctic E. raboti) and Laophonte mahammed.
Amphipods collected by L. S. Berg, A. V. Martynov, include an endemic genus Issy-kogammarus inherent in the depths of the lake, and several new species of the genus Gammarus (Berg, 1904). The formation of this brackish-water genus, several species and subspecies limited to the endemism of the fauna. The marine element in the fauna of the Issyk-Kul is missing.
It is not penetrated by Chu river from the Aral sea. Recently in Issyk-Kul were acclimatized some species of fish, for example gegarkuni Sevan trout Salmo ischchan gegarkuni infraspecies.
Thus, four groups of organisms, selected Vereshchagin (a), in the formation of the fauna of the Issyk-Kul, participated three. Of these, most important were the organisms that entered the tributaries of the lake.
A peculiar feature formed of endemic ichthyofauna of the Issyk-Kul lake is the absence of deep-water fish and fish that eat plankton. The reason for this poverty of zooplankton, which in summer is concentrated in the lake in the upper 100-m layer of water. At great depths it was very poor due to unfavourable trophic conditions.
Phytoplankton in the open part of the lake consists of three main representative: Bothryococcus braunii, Amphiprora paludosa var. issikkulensis and Peridinium bergei. The latter species is much less the first two. With very weak development of phytoplankton does not create a forage base for zooplankton and, consequently, for deep-sea and pelagic fishes.
Soils in Issyk-Kul, according to L. S. Berg (1904), is strongly limed sludges, they have a lot of little ostracods and oligochaetes. Such silts are confined not only to the Bush charophytes. L. S. Berg (1904) indicates that they cover the bottom of the lake to the greatest depths. Fact the sedimentation of the carbonates suggests that Issyk-Kul is currently at the third stage holotropnoe type limnogenez.
Fourth largest lake with calotropis type of development of the Balkhash – began its life as a completely closed water basin, never having any connection with sea water type. In shaping its flora and fauna participated all groups of organisms, these G. Y. Vereshchagin (li940a) for lakes, except for the first.
The main role is played by representatives of the fauna of the highland Asia region, with which the Balkhash once had a relationship through the Dzungarian gates during the period of glaciation of the mountains Tekeli. L. S. Berg (1955) indicates the last communication with Balkhash lake EBI-Nur. We have shown that this communication could take place only during the existence of the Great great-Balkhash lake, when the lake level was 140 m higher than at present.
Lake EBI-Nur was located in this time is much lower Balkhash. Obviously, part of the waters of the Great great-Balkhash lake shimmered at the Dzungarian gates down to EBI-Nur, which created the possibility of penetration into the Balkhash fauna of the mountainous Asia (Abrosov, 1973). Great great-Balkhash existed after Tula glaciation in the subsequent inter-glacial period.