Meeting Abstract

90.5  Thursday, Jan. 7  Respiratory and Olfactory Turbinate Dimensions in Aquatic and Terrestrial Carnivorans VAN VALKENBURGH, Blaire*; SAMUELS, Josh/X; BIRD, Deborah; MEACHEN-SAMUELS, Julie; Univ. of California, Los Angeles; Univ. of California, Los Angeles; Univ. of California, Los Angeles; Univ. of California, Los Angeles bvanval@ucla.edu

The mammalian nose contains an extensive set of scroll-like, paper-thin bones known as turbinates (or turbinals). The turbinates are a fundamental feature of the class Mammalia and key to two of their hallmark features, endothermy and olfaction, and yet we know relatively little about their anatomy and function. We used high-resolution CT scan data to quantitatively analyze turbinate structure and scaling in a wide range of carnivorans. Measurements include nasal cavity volume, respiratory, and olfactory turbinate surface areas. The varying thermoregulatory, locomotor, and olfactory demands among living carnivorans suggest that species with differing ecologies should have different turbinate dimensions. For example marine species are expected to have enhanced respiratory surface area in response to greater demands for heat and water conservation. A comparison of aquatic and terrestrial species in four families (Ursidae, Mustelidae, Otariidae, and Phocidae) reveals that aquatic species (both freshwater and marine) exhibit reduced olfactory surface areas and greatly expanded respiratory surface areas. The one exception is the extinct, tropical Caribbean monk seal ( Monachus tropicalis ) that has a respiratory surface area similar to that of terrestrial species. This, and the fact that the river otter ( Lontra canadensis), a species with ready access to drinking water, has expanded respiratory surface area, suggest that the primary function of the respiratory turbinates is heat rather than water conservation in both the aquatic piinipeds and mustelids.