Toxicity Toward Fish and Other Aquatic Organisms

Toxicity Toward Fish and Other Aquatic Organisms 

A much lower sensitivity has been reported in tests with other fish (202). Probably the size of the fish as well as their species will affect their sensitivity to the photosensitizer, but no detailed studies in this area have been reported. 

Another point of interest in relation to possible applications of a-terthienyl as a biocide is the relationship between initial exposure of the organism to the chemical and its irradiation. In laboratory experiments. 

The duration of the fish incubation with the chemical prior to irradiation also affects the phototoxicity of a-terthienyl. In the experimental conditions selected, the survival was 100% when the fish were irradiated for 30 min immediately upon contact with the solution, 0% when irradiated after 2 h, and 70% when the irradiation was started 8 h after initial contact. This indicated that a) a minimum incubation period was required for the sensitizer to reach the biological targets leading to lethal damage, and b) depuration took place. However, nothing is known about the relationship between the initial concentration of sensitizer and the magnitude of this phenomenon (757). 

Late embryonic stages of Rana pipiens (757) and Hyla crucifer (757) were found to be extremely sensitive to the effect of a-terthienyl in vitro, but only in the presence of sunlight. The phototoxicity level was comparable to that recorded with first-instar larvae of the mosquito Aedes aegypti (759). The relationship between developmental stage and 

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