|Dessication and age as factors in the vertical distribution of the dog-whelk, Nucella lapillus|In: Journal of Zoology (1987). Zoological Society of London: London. ISSN 0952-8369, more
Desiccation tolerance levels have been estimated for Nucella in relation to specific age-groups which occupy distinct tidal levels. The values obtained have been shown to follow the natural age progression, and hence the natural zonation levels. The likelihood of critical or lethal fluid-loss values being reached during six-hour periods of exposure in absence of both shelter and consideration of natural zonation has been investigated. It is concluded that Nucella attempts to prevent loss of excessive volumes of fluid during emersion by occupying specific tidal levels in accordance with natural fluid-loss tolerances. The species is further assisted by a natural inclination to seek sheltered positions during rough weather, and the presence of a comparatively large reservoir of fluid held extra-viscerally in the mantle cavity.