PARENT SESSION

PW12 Pesticide II
Exhibit Hall
8:00 AM - Wednesday

(PW206) Environmentally Realistic Levels of Atrazine (But Not Malathion) Impair Protein Metabolism in Red Drum (Sciaenops ocellatus) Larvae.

Samberson, Hunter¹, Fuiman, Lee¹, McCarthy, Ian², ¹ The University of Texas at Austin Marine Science Institute, Port Aransas, TX, United States² School of Ocean Sciences University of Wales, Bangor, Wales, United Kingdom

ABSTRACT- Rates of protein synthesis and protein growth were measured in red drum (Sciaenops ocellatus) larvae exposed to environmentally realistic levels of one of two pesticides, atrazine or malathion. Larvae were exposed to 0, 40, or 80 g/l atrazine or 0, 1, or 10 g/l malathion for 8 d and sampled after 2, 4, and 8 days to assess protein synthesis rate and protein growth. Protein growth and synthesis measurements were made by bathing larvae in a flooding dose of ³H-phenylalanine for 4 h. Protein synthesis rates were not affected by exposure to either pesticide. Protein growth, however, was significantly reduced in larvae exposed to atrazine, but not malathion. These results imply that the reduced protein growth found in larvae exposed to atrazine was caused by an increased rate of protein breakdown. Such a reduction in protein growth for larvae exposed to atrazine would prolong the highly vulnerable larval period, resulting in higher mortality rates and lower recruitment success. Malathion did not appear to interfere with protein metabolism.

Key words: atrazine, Sciaenops ocellatus, protein metabolism