show Abstracthide AbstractThe olfactory gene repertoire is largely species-specific, shaped by the nature and necessity of chemosensory information for survival in each species' niche. The relative expression of olfactory receptors can be quantified by RNA sequencing. We investigated the olfactory transcriptome of zebrafish because : i) of its phylogenetic location in the vertebrate tree, ii) it has only one olfactory organ (yet it has representatives of all the mammalian chemosensory receptor families), iii) its biology is well known, iv) is a commonly used model organism, and it is suitable for subsequent functional analysis.