Jackson Estuarine Laboratory

Effects of Egg Concentrations of DDT and Dieldrin on Development in Winter Flounder (Pseudopleuronectes americanus)


Abnormal gastrulation and a high incidence (mean = 39%) of vertebral deformities at hatching were encountered in developing eggs from winter flounder, Pseudopleuronectes americanus, experimentally exposed as adults to sublethal concentrations of DDT. Bone erosion and hemorrhaging at the vertebral junctures were often observed in conjunction with the vertebral deformities. No abnormal gastrulation and a lower incidence (mean < 1%) of vertebral deformities without bone erosion and hemorrhaging were encountered in controls. DDT concentrations in the eggs ranged from 0.39 to 4.60 (mean = 2.42 ppm) compared to 0.11–0.57 ppm (mean = 0.22 ppm) in the eggs from control flounder. No observable effect on development was noted in eggs from adults exposed experimentally only to dieldrin except in two lots of eggs most of which were dead and necrotic at spawning and contained 1.74 and 1.21 ppm dieldrin. No direct effect on fertilization mortality was due to gamete concentrations of DDT and dieldrin and no residues of either insecticide were detected in the milt from exposed or control male flounder.

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Journal of the Fisheries Research Board of Canada

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