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INTRODUCTION (abstract of the PhD thesis)
The aim of the research
is to determine the species composition of fish found
in
the Surkhan Darya basin, their distribution across the basins,
to determine the
taxonomic differences of species based on morphometric indicators,
and to form
geoinformation data on the distribution of fish species in the basin.
The object of the research
is the fish fauna distributed in the water bodies of
the Surkhan Darya river basin.
The scientific novelty of the research is as follows:
- The modern state of the fish fauna of the Surkhan Darya river basin, the
composition of species was determined, and it was determined that the fish fauna
consists of 37 species belonging to 7 orders, 15 families, and 34 genera;
- For the first time, a new species for the ichthyofauna of Uzbekistan, the
Gobio
sibiricus
, was identified from Surkhan Darya river basin. Until that time, only one
Gobio
genus was known in the ichthyofauna
of Uzbekistan -
Gobio lepidolaemus
;
- molecular identification of
Gobio sibiricus
and
Alburnoides holciki
were
carried out based on nucleotides of the cytochrome oxidase I (COI) barcode gene of
mitochondrial DNA (mtDNA);
-
Alburnoides holciki
was found to be the dominant
species common in the
Surkhan Darya river basin;
- It was found that fish species formed their habitats in the lower, middle and
upper streams of the basin based on the characteristic of
adaptive adaptation;
- For the first time, the length and weight relationships of local and endemic
fish species distributed in the basin were analyzed;
- The description, calculation, and size of fish species
that are important for
hunting and rare and threatened with extinction have been formed.
