Kiarna Taylor

Microbiome characterization of two epidermal regions containing different denticle structures on the shark, Heterodontus portusjacksoni

The epidermal microbiome of sharks is species-specific and distinct from the water column, suggesting there is a strong filtering effect of the shark epidermis. Whether dermal denticles or epithelial mucus functions are the major structuring component of the epidermal microbiomes remains an outstanding question. The study aims to characterize the Port Jackson shark dorsal and ventral epidermal microbiome which contain distinguishable denticle textures. The denticles on the dorsal surface are elevated, crowned-shaped, and non-overlapping, whereas on the ventral side they are flattened, and rounded with little interdenticle space.

The analysis is being conducted on the same shark species, which will keep the influence of the shark’s metabolism (i.e., excretion of proteins etc., in the mucus) consistent across locations on the shark. Therefore, the two epidermal microbiomes, and the microbial communities in the surrounding seawater will be compared. This research will determine whether the epidermal microbiome is being broadly affected by the environment, or if the host has a filtering or selective mechanism. Differences in community composition between skin regions will provide evidence on how denticle morphology influences microbial ahesion onto true shark skin. Researching various elasmobranch species will develop an understanding of the interactions between host genetic properties and the resident microbiome.