Meeting Abstract
Elasmobranchs (sharks, skates, and rays) are known for their acute olfactory sense. Olfactory system morphology is diverse and varies interspecifically, but the links between morphology and function are unclear. We hypothesize that variations in morphology impact the fluid flow through the olfactory organ and in turn have consequences for olfactory sensitivity. The shark olfactory system consists of an incurrent channel, an excurrent channel, and the organ itself, which is comprised of two rows of lamellae, which are overlain with olfactory epithelium. The shape of the organ and number of lamellae vary dramatically among species. Our goal was to use bioinspired models to examine the impacts of varying organ shape and lamellar number on flow through the olfactory organ. We based bioinspired models on varying meristics for the organ (length, width, and depth) and for the lamellae (number, width, and interlamellar distances). Particle Image Velocimetry was used to quantify the effects of meristic variation on flow patterns and rates through the model. We found that vortices are generated in each interlamellar space. In addition, we observed that flow distribution between lamella changes along the length of the organ. These flow characteristics likely have implications for odorant biding. However, these flow structures still need to be corroborated at lower Reynolds number. These data suggest that the variations in olfactory morphology may be important for distributing fluid through the system to the sensory epithelia and information processing.
