There are those who have questioned the reason for getting fish drunk. I could stumble through the explanation and make the issue much more confusing than it has to be, or I could just post a few of research articles I used to design my experiment.
Gerlai, R., Lahav, M., Guo, S., Rosenthal, A. 2001. Drinks Like a fish: zebra fish (Danio rerio) as a behavior genetic model to study alcohol effects. Pharmacology, Biochemistry and Behavior. 67:773-782
Dlugos, C.A., Rabin, R.A., 2003. Ethanol effects on three strains of zebrafish: model system for genetic investigations. Pharmacology, Biochemistry, and Behavior. 74:471-780