BEHAVIOR AND BRAIN CHEMISTRY CORRELATES IN MUMMICHOGS (FUNDULUS-HETEROCLITUS) FROM POLLUTED AND UNPOLLUTED ENVIRONMENTS

The ability of Fundulus from a polluted environment to capture a prey organism, the grass shrimp (Palaemonetes pugio), was compared to that of Fundulus from an unpolluted reference site. Fish from the unpollute d site took significantly more prey (p < 0.1) during the first 5-10 mi n of each trial than fish from the polluted site. Analysis of the neur otransmitters dopamine (DA) and serotonin (5-HT) and their metabolites , DOPAC, homovanillic acid (HVA), and 5-hydroxy-indolacetic acid (5-HI AA) in cerebellums and medullas was performed by HPLC. Mummichogs from the polluted site had significantly lower concentrations of 5-HT and its metabolite 5-HIAA in their medullas, but not cerebellums, than fis h from the reference site (p < 0.05). Concentrations of DA, DOPAC and HVA were not different between populations in either part of the brain . Neurotransmitter concentrations were shown to be independent of size and therefore, presumably, age. Analysis of Hg in livers and brains o f these mummichogs by atomic absorption spectrophotometry showed signi ficant differences between the two populations for both organs. Earlie r work showed that the behavioral deficit could he elicited by Hg; thu s, this was the putative neurotoxic agent. However, there are other ca ndidates which may contribute to neurotoxicity in the study site.