Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Biology Dept.


Catherine R. Bevier

Second Advisor

W. Herbert Wilson

Third Advisor

Joshua Kavaler


Maternal consumption of alcohol may subject the fetus to fetal alcohol syndrome or fetal alcohol spectrum disorders (FAS or FASD). FAS/D is a public health problem, and affected children are defined by varying degrees of irreversible mental retardation, physical defects, behavioral issues, and vision problems from prenatal alcohol exposure (Riley et al. 2011). Recent studies on FAS have looked towards animal models, such as zebrafish, Danio rerio, that exhibit homologous physical and behavioral effects of alcohol (Bilotta et al. 2004). I exposed zebrafish embryos to low doses of ethanol (0.5% v/v or 1% v/v) in either chronic (at least 8 h of exposure) or acute (1 or 4 h of exposure; up to four times before hatching) patterns at different points during development. I tested the hypothesis that the effects of the ethanol exposure on the morphology, function, and behavior of zebrafish vary depending on the exposure period and stage of development, and that the severity of physical, functional, and behavioral differences in ethanol exposed groups are related to ethanol concentration. The results show that embryonic exposure to low doses of ethanol indeed affects the morphology, function, and behavior of larval zebrafish. Embryos in chronic exposure treatments exhibited differences in morphology in a dose dependent and stage specific manner, and in physiology regardless of morphological differences. Embryos in acute exposure treatments exhibited differences in morphology in a dose and somewhat frequency dependent manner; physiology of these zebrafish was affected regardless of morphological differences. Results from one acute treatment group suggests there is a threshold at which low doses of ethanol for short durations or at specific stages of development would not physiologically or morphologically affect the zebrafish. Behavioral data on one chronic treatment group demonstrated increased preference for lit environments, which may reflect eye function.


fetal alcohol syndrome, fetal alcohol syndrome disorder

Multimedia URL