饵料浓度和成体密度对汤氏纺锤水蚤(Acartia tonsa)产粪粒数、产卵和孵化的影响

EFFECTS OF FOOD CONCENTRATION AND STOCKING DENSITY ON FECAL PELLET GENERATION,EGG PRODUCTION AND HATCHING SUCCESS OF CLANOID COPEPOD ACARTIA TONSA

采用静水法研究了不同饵料浓度和成体密度对汤氏纺锤水蚤产粪粒数(FP)、产卵(EP)和孵化(HS)的影响。根据碳含量设定250、500、1000、1500、2000和3000μgC/L六个饵料浓度梯度,以及40、80和160个/L三个成体密度进行实验。结果表明,在成体密度为40和80个/L时,汤氏纺锤水蚤的平均产粪粒数随着饵料浓度的增加而增加;在饵料密度高于500μgC/L时,成体密度为160个/L的产粪粒数显著低于其它两组(P<0.05)。饵料浓度和成体密度对产卵量影响显著,在相同成体密度下,产卵量随着饵料密度的提高而增加;在饵料密度高于500μgC/L时,成体密度为160个/L的产卵量显著低于其它两组(P<0.05)。汤氏纺锤水蚤卵的孵化率受饵料浓度和成体密度的影响不大。

The effects of food concentration and stocking density on fecal pellet （FP） generation, egg production （EP） and 48h egg hatching success （HS） ofAcartia tonsa were examined in laboratory. Algal densities tested were equivalent in carbon concentrations and corresponded to 250, 500, 1000, 1500, 2000, and 3000ktgC/L of Rhinomonas reticulate. Three stocking densities in 40, 80 and 160 adults/L were setup for all experiments in 4 replicates per treatment. The results show that at stocking density of 40 and 80 adults/L, mean FP production was dependent on the density of food supply. At the stocking density of 160 adults/L, the mean FP production was significantly lower than 40 and 80 adults/L when food con- centration above 500~tgC/L （P〈0.05）. The food concentration and stocking density significantly affected the EP ofA. tonsa Mean EP increased with the increase of food concentrations at the same stocking density. At the stocking density of 160 adults/L, the mean EP production was significantly lower than 40 and 80 adults/L when the food concentration above 500~tgC/L （P〈0.05）. In this species, HS was not strongly affected by differences in food concentration and stocking density.