Pennsylvania State University Altoona 1 article published in JoVE Behavior A Standardized Protocol for Preference Testing to Assess Fish Welfare Cairsty DePasquale1, Jennifer Sturgill1, Victoria A. Braithwaite2 1Department of Biology, Pennsylvania State University - Altoona, 2Department of Ecosystem Science & Management, Pennsylvania State University A fundamental aspect of assessing the welfare of animals in captivity is to ask whether the animals have what they want. Here, we present a protocol to determine housing preference in the zebrafish (Danio rerio) with respect to the presence/absence of environmental enrichment and access to flowing of water.