Aversive Response of Grey (Halichoerus grypus) and Harbour (Phoca vitulina) Seals Exposed to Camphor: A New Approach to Keep Seals Away from Sensitive Areas?

• Published in: Aquatic Mammals
• Main Authors: Campagna, S, Hansen, KA, Wahlberg, M, Celerier, A
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: AFRICAN FUR SEALS; OLFACTORY DISCRIMINATION; ODORANTS; CHANNELS; Phoca vitulina
• Online Access: https://portal.findresearcher.sdu.dk/da/publications/1cb3d1c2-a2a5-49c1-b3ef-f64de01a15b2; https://doi.org/10.1578/AM.48.6.2022.634

Pinnipeds are semi-aquatic mammals that face a constantly changing environment as they move from land to water. Such an amphibious lifestyle has required specific physiological adaptations— for example, in their sensory systems: visual, acoustic, tactile, and chemical (olfactory and gustatory) modes. Their gustatory system has not been studied in detail, so little is known about their chemoreception abilities. Still, some information is available; in comparison to terrestrial mammals, pinnipeds have a reduced number of taste buds, suggesting a limited sense of taste (Kastelein et al., 1997; Yoshimura & Kobayashi, 1997). The ability to detect acidic and salty solutions has been demonstrated in Steller sea lions (Eumetopias jubatus; Kuznetsov, 1982) and California sea lions (Zalophus californianus; Friedl et al., 1990), and both species did not respond to sweet tastes. Indeed, the TAS1R2 and TAS1R3 genes encoding the sweet taste receptors are not functional, at least in several species of pinnipeds (Jiang et al., 2012; Wolsan & Sato, 2020), including nine species of phocids and six species of otariids (Wolsan & Sato, 2020). The umami taste receptors were also found to be pseudogenized (Jiang et al., 2012; Wolsan & Sato, 2020). Although the gustatory abilities of pinnipeds appear limited, a high sensitivity to slight differences of salt concentration has been demonstrated in harbour seals (Phoca vitulina). As salinity levels represent a potential source of information for orientation in marine environments, sensitivity to salt could be involved in fine-scale underwater movements (Sticken & Dehnhardt, 2000).