Ontogenetic and Geographic Variability in Epidermal Club Cell Densities in White Suckers (Catostomus commersonii)

Abstract

Fish species from the superorder Ostariophysi (minnows, catfish, suckers etc) possess specialized epidermal club cells (ECCs), which are associated with pheromones that trigger alarm responses when damaged. The density of these cells has been linked to a variety of ecological factors including health, predation risk, pathogens, and exposure to UV radiation. All of these factors are likely to vary geographically, across different bodies of water (lakes, rivers, streams). However, research in this topic is very limited to one paper. Another research direction has originated from our labs; and that is an association between ECC densities (cells/mm2 of tissue) and fish length, revealed in several minnow species. Trying to better understand this link, we set out to investigate factors that contribute to the variation in ECC density within the Ostariophysi superorder. For this study, we investigated the White Sucker (Catostomidae Family), as compared to previous UWEC studies, which used minnows (Cyprinidae Family). Examine the variation of ECC density of White Sucker specimens from different bodies of water (lakes, streams, and rivers). Determine if a relationship exists between ECC density and length within the White Sucker species. Analyze ECC density in the White Sucker species and compare them to ECC densities in previously studied Cyprinids (Creek Chub, Hornyhead Chub, and Blacknose Dace).