Rm. Rose et al., The presence of chemicals exuded by fish affects the life-history responseof Ceriodaphnia cf dubia to chemicals with different mechanisms of action, ENV TOX CH, 20(12), 2001, pp. 2892-2898
The toxicity of chemicals with different mechanisms of action (3,4-dichloro
aniline, fenoxycarb, and chlorpyrifos) to the cladoceran Ceriodaphnia cf. d
ubia was examined in the presence and absence of chemicals exuded by fish,
termed fish kairomones. A range of life-history traits were examined. inclu
ding mean brood sizes, survival, net reproductive rate (R-o) and population
growth rate (r). Cladocerans exposed to 3,4-dichloroaniline showed similar
sensitivities in the presence and absence of fish kairomones with respect
to all of the life-history traits examined. The presence of fish kairomones
reduced the sensitivity of cladocerans to fenoxycarb with respect to mean
brood sizes and r but increased their sensitivity in terms of R-o. The pres
ence of fish kairomones increased the sensitivity of cladocerans to chlorpy
rifos with respect to survival, r, R-o, and mean brood sizes. The general t
rends observed were similar to those shown when C. cf. dubia was exposed to
these chemicals under low food conditions, and it is suggested that the ef
fects of fish kairomones on toxicity may be attributed to the reduction in
feeding rates observed when C. cf. dubia is exposed to fish kairomones.