Plankton Community Structure Characteristics in Traditional Polyculture Ponds During Main Culture Period
Aiming to understand the characteristics and influencing factors of plankton community structure in polyculture ponds in the middle and lower reaches of the Yangtze River throughout the main culture period,the water physical and chemical indices and plankton community structure were determined in two ponds where Nile tilapia"Zhongwei No.1"(Oreochromis niloticus)and common carp"Furui carp No.2"(Cyprinus carpio)were polycultured with silver carp(Hypophthalmichthys molitrix)and bighead carp(H.nobilis)at the Yixing Qiting Scientific Research Experimental Base of the Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences by a conventional fingerling rearing pattern every interval of 15-25 d from May to September in 2019,during the main culture period.Results showed that the concentrations of total nitrogen and ammonia nitrogen were all enhanced,and gradually level off throughout the culture period,with low level of nitrite nitrogen and increase and then decrease in total phosphorous concentration.There were 8 phyla and 77 genera of phytoplankton in the ponds,mainly belong to Chlorophyta and Cyanophyta;and there were 5 classes and 72 species of zooplankton,most species belong to protozoa and rotifers.Principal component analysis(PCA)and heat map based on plankton abundances revealed that the community structure of plankton showed obvious temporal changes pattern,the dominant species and their densities were different during the culture period.The redundancy analysis(RDA)demonstrated that nitrite and total nitrogen concentrations had significant effects on phytoplankton abundance(P<0.05);and that water temperature,pH and nitrite concentration had significant effects on zooplankton abundance(P<0.05).The significant linear correlations were observed between 14 dominant species densities and physicochemical index values(P<0.05).The temporal variation in the plankton community structure in the polycultured ponds was shown to be obvious,with differences in the main physicochemical indicators in the water during the main cultured period.The findings provide basic data for water quality monitoring,control and management of polyculture ponds.
NETL
NSTL
万方数据
