Mortality, copepods

Table 8.5. Triaenophorus crassus experimental infection of copepods. Mortality of infected and uninfected Cyclops bicuspidatus thomasi and prevalence in cyclopids by host sex. (Data from Rosen Dick, 1983,)...

Note L, low level exposure 58 coracidia per copepod. H, high level of exposure 116 coracidia per copepod. Mortality, no. control dead/total controls and no. of infected dead/total infected. Prevalence, no. infected/no. exposed p.i., post infection p.e., post exposure. 

H.E. Zagarese, W. Cravero, P. Gonzalez, F. Pedrozo (1998). Copepod mortality induced by fluctuating levels of natural ultraviolet radiation simulating vertical mixing. Limnol. Oceanogr., 43,169-174. 

Interactions of merciuy with other toxic substances have not been studied extensively, but some information does exist with respect to copper. In studies of the antifouling properties of these two metals, Barnes and Stanbury (1948) using the copepod Nitrocra spinepes noted that copper and mercury acted synergistically. They reported that the exposure of animals to 0.4 mg/L of merciuy resulted in a 17% mortality after 24 hrs, whilst 2.6 mg/L of copper gave a mortality of 20%. However, a mixture of the two materials at these concentrations produced a mortality of 98%, i.e., a 3x increase above the expected additive value. Similar results have been reported by Corner and Sparrow (1956) and by Hunter (1949). However, Roales and Perlmutter (1974) reported that copper apparently inhibits the toxicity of methyl mercury chloride to an American freshwater fish, Trichogaster trichopterus. 

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