Vliv možnosti šíření žábronožek (Crustacea: Anostraca) na genetickou strukturu populací

Abstract

1 ABSTRACT The coldstenothermal species Eubranchipus grubii (Dybowski, 1860) is restricted only to vernal temporary pools in floodplain and does not occur in any other type of water habitat. Organisms living in these habitats have to be well adapted to low temperatures, desiccation, low nutrient levels, and have the ability to migrate among habitats and colonize newly established ones. E. grubii survives periods of desiccation in the form of cyst. These cysts serve as a mean of dispersion. In the Czech Republic E. grubii occurs in watersheds of rivers Labe, Morava, Odra and Dyje. We collected 95 populations in these different regions. The extent of genetic divergence among populations was assessed by analyzing sequence variation in mitochondrial gene (COI). Comparing levels of mtDNA sequence divergence divided studied populations into three main groups according to watersheds. Genetic relationships among populations inhabiting different watersheds showed 1,7 - 5,7 % sequence divergence. Sequence divergence within populations is very small. It seems that E. grubii colonized the area of today's Czech Republic from different refugia.