河蟹生态育苗池桡足类群落结构的研究

报道了辽河三角洲河蟹(Eriocheir sinensis)生态育苗池中桡足类的种类组成、密度、生物量、时空分布和昼夜垂直移动。结果表明,育苗池中有近亲真宽水蚤(Eurytemor affinis),细巧华哲水蚤(Sinocalnus tenllus),中华哲水蚤(Calanus sinicus),指状许水蚤(Schmackeria inopinus),咸水剑水蚤(Halicyclopssp.),裂囊猛水蚤(Schizoperasp.),异水蚤(Acartiellasp.)等7种桡足类。其中,近亲真宽水蚤和细巧华哲水蚤为优势种,平均密度分别为233ind/L和92.3 ind/L,桡足类的密度变幅为20~1540 ind/L。桡足类的水平分布在育苗前期上、下风位比较均匀,但育苗期下风位>上风位,差异极显著(P<0.01);桡足类的垂直分布育苗前期规律不明显,育苗期底层>表层,差异显著(P<0.05);桡足类的昼夜垂直移动变化为白天表层>底层,晚上分布比较均匀;桡足类的空间分布特点与河蟹幼体在池塘中的空间分布特点密切相关。

A Study on Copepods Community Structure in Ecological Breeding Ponds of Chinese Mitten Crab (Eriocheir sinensis) Larvae

This study was conducted to investigate the species composition, density,biomass,temporal and spatial distribution,and diel vertical migration of copepods in ecological breeding ponds,located at Liaohe Delta district to cultivate Eriocheir sinensis larvae.The result indicates that there are 7 copepods species: Eurytemor affinis,Sinocalnus tenllus,Calanus sinicus,Schmackeria inopinus,Halicyclops sp.,Schizopera sp.and Acartiella sp.,of which E.affinis and S.tenllus are dominant species in the ponds,and their mean density is 233?ind/L and 92.3?ind/L respectively.Moreover,the density of copepods in the ponds ranges from 20 to 1540?ind/L.During the breeding stage,the copepods density in downwind zone is significantly higher(P<0.01) than that in upwind zone,but during the pro-stage,it is similar in both zones.And in pro-stage,the vertical distribution rhythm of copepods is unconspicuous,while in breeding stage,the copepods density in bottom zone is higher(P<0.05) than that in surface zone.For diel vertical migration of copepods it is relatively uniform in both zones at night,but by daylight the copepods density in surface zone is higher than that in bottom zone.The data demonstrates that the temporal and spatial distribution characteristic of copepods is closely related with that of Eriocheir sinensis larvae in the ponds.