培养基和放养密度对池塘底质及底栖动物的影响

研究了3种底栖动物培养基和3种虾、蟹混养方式对池塘底质总氮、总磷、总有机碳积累量和底栖动物种类及其生物量的影响。3种培养基（底栖饵料生物、鸡粪、鸡粪与猪粪混合）和3种虾、蟹混养方式（虾、蟹分别为6000、1000,8000、800,10000、300 ind./667 m2,虾放养规格为300-400尾/kg,蟹放养规格为120只/kg）按随机区组排列,共设置9个试验组,每组设3个重复。结果表明：底栖饵料生物培养基组的总氮、总磷和总有机碳积累量均显著低于鸡粪培养基和鸡粪与猪粪混合培养基组（P〈0.05）,而底栖动物种类及总生物量明显高于其他培养基组（ P〈0.05）；在不同培养基条件下,高密度克氏原螯虾Procambarus clarkia组底质中总氮、总磷和总有机碳积累量均显著高于克氏原螯虾中、低密度组（P〈0.05）,而底栖动物生物量明显低于中、低密度组（P〈0.05）；养殖密度水平对底栖动物种类则无显著影响（P〉0.05）。研究表明,为兼顾生态效益和经济效益,采用底栖饵料生物培养基,克氏原螯虾与河蟹Eriocheir sinensis的养殖密度分别为8000、800 ind./667 m2时的组合为最佳。

Effects of culture medium and stocking density on substrate and benthic animals in a pond

The effects of three culture media（ benthic bait biological culture medium, chicken manure, and mixture of chicken manure with pig manure） and three stocking densities in 9 polyculture regimes of red swamp prawn Pro-cambarus clarkii（6000,8000 and 10 000 ind. /667 m2 , 300-400 ind. /kg） and Chinese mitten handed crab Erio-cheir sinensis（1000, 800 and 300 ind. /667 m2 , 120 ind. /kg） on total nitrogen, total phosphorus, total organic carbon and the benthic animals were studied with triplication. The results showed that there were significantly lower levels of total nitrogen, total phosphorus and total organic carbon in the benthic bait biological culture groups than those in the chicken manure and the mixtures of chicken manure with pig manure groups （P〈0. 05）. However, there were significantly higher species number and total biomass of benthic animals in benthic bait biological culture medium groups than those in the chicken manure and the mixtures of chicken manure with pig manure groups （ P〈0. 05）. The levels of total nitrogen, total phosphorus and total organic carbon were found significantly higher in the high density of red swamp prawn groups than those in the medium density and low density groups （P〈0. 05）,and the significantly lower total biomass of benthic animals in the high density red swamp prawn group than in other groups （P〈0. 05）, without significant differences in species of benthic animals at all density levels（P〉0. 05）. The findings suggest that the optimal stocking density be 8000 red swamp prawn juveniles and 800 Chinese mitten hand-ed crab juveniles per 667 m2 in the benthic bait biological culture medium ponds from the consideration of ecological benefit and economic benefit.