The enteric nervous system (ENS) consists of neurons and glia that control motility, secretions, and blood flow within the gastrointestinal tract. Using the zebrafish, Danio rerio, as a model we aim to understand ENS development and how this process might go array in disorders such as Hirschsprung’s, in which children are born lacking neurons in portions of their gastrointestinal tract. The number of markers for enteric glia is relatively small and many of the current immunohistochemical approaches are confounded by the uncertainty of cross-reactivity patterns between species. In preliminary experiments using established glia markers, we obtained unexpected results identifying glia in mutants lacking the ENS, suggesting a lack of glia marker specificity, or the presence of an uncharacterized subpopulation of glia in our mutants. To distinguish between these possibilities, we have cloned other markers to examine glia populations in normal larvae and larvae with defects in ENS development.