The impact of rice-crab culture system on crustacean zooplankton community

Abstract:

During the tilling, tillering, jointing, flowering and filling stages, a study was carried out on community of crustacean zooplankton in water environment of rice-crab culture model. This experiment included four treatments: a single seedling transplant of rice-crab culture(T1), a double seedling transplant of rice-crab culture(T2), a four seedling transplanting of rice-crab(T4) and a double seedling transplant of paddy without crab(CK). There were 3 parallel groups in each treatment. After being identified, 13 species of Cladocera and 5 species of Copepoda were found, and four species were dominant. Cladocera average density presented downward trend after rising first, rose to its highest in tillering stage, not crab filling paddy field down to a low level to filling stage. Crab filling paddy field in flowering went down to lower levels,then rose but rose slightly. During the tilling and tillering stages no significant differences were observed between the groups (P>0.05), while in jointing stage, flowering and filling periods, no significant differences were observed between paddy fields (P<0.01); The copepods density in general is on the rise trend, reviving an average density is very low, only 0. 48 ind/L during tilling stage. Average trend of changes in biomass and the trend of density were basically the same. Different cultivation patterns of rice have a certain impact on crustacean zooplankton. From the perspective of the production model analysis, the single seedling transplant of rice-crab culture method may be more beneficial to rice-crab culture ecosystem.