PRELIMINARY RESULTS OF THE RESEARCH OF DIVERSITY COMPOSITION OF SPECIES AND BIOMASS OF ZOOPLANKTON IN THE SILVER CARP POND HYPOPHTHALMICHTHYS MOLITRIX (VALENCIENNES,1884) IN THANH HOA PROVINCE

Abstract

The study was conducted in 3 districts of Dong Son, Thieu Hoa and Yen Dinh, in Thanh
Hoa province, these are the key farming districts with a larger proportion of polyculture of Silver
carp Hypophthalmichthys molitrix (Valenciennes, 1884) than other districts in the province. The
study results found that 04 varieties and species of zooplankton in the study area: 01 species of
the genus Mongolodiaptomus (Pennak, 1951) and 03 species of Brachionus calyciflorus (Pallas,
1883); Brachionus diversicornis (Daday, 1883) and Brachionus plicatilis (Muller, 1883) of the
phylum Rotifera). Feeding formula No. 2 (50% rotted manure + 50% industrial feed) with diverse
species composition and biomass had the highest average density of 29,798,333.3 individuals/1
liter of water (the Formula 1 has an lowest average density of 8,982,333.3 individuals/1 liter of
pond water); The pond bottom containing mud, sand and the water source in Ma River in Thieu
Chinh commune has the highest density and biomass of zooplankton at 47,550,000 individuals of
zooplankton/1 liter of water, the lowest was sand, mud and water source at Lake Ren, Dong
Hoang commune (reaching 811,333.3 individuals of zooplankton/1 liter of water).