Responses of the marsh periwinkle,Littoraria (Littorina) irroratato temperature, salinity and desiccation, and the potential physiological relationship to climbing behavior

Abstract

Littoraria irrorata climb the vertical stems of Sparlina alterniflora in the face of an advancing tide. This behavior, while allowing escape from predators, may also be correlated with the physiological responses of the organism to variations in physical factors typically found in an estuarine salt marsh. To test this hypothesis, snails were exposed to changes in environmental salinity, their resistance to desiccation was determined, and their ability to take up oxygen from both water and air was measured at varying temperatures. L. irrorata were found to be tolerant to wide variations in salinity. The mechanism employed appears to be intracellular volume regulation, which is common in many other marine and estuarine species. This species is also very tolerant of desiccation, surviving after losing nearly 70% of its soft tissue weight over a period of two weeks. Upon contact with water, it quickly rehydrates, regaining its initial weight within one hour. At low temperature (20°C) aquatic and aerial oxygen...