Acid secretion in the Pacific Ocean gastropods

Abstract

Acid secretion is recorded for 22 species of Pacific Ocean gastropods. Pleurobranchus peroni, Cypraea clandestina, C. spadicea, and Lamellaria sp. were investigated in detail. It was established that the "empty" epidermal cells of P. peroni elaborate and secrete the acid and it is suggested that cells of similar appearance in the other species have the same function. The acid is discharged, following abrupt disturbance, by rupture of the epidermal acid cells in most species, but through permanent pores in Lamellaria sp. Tests suggest that the secretion is predominantly sulphuric acid. The structure of the epidermal acid cells was investigated with the electron microscope and the formation and coalescence of acid vacuoles are described. A second type of epidermal cell, found in P. peroni and C. spadicea, contains longitudinally striated material and is believed to play a mechanically supporting role. Mucous goblet cells and sparse epidermal cilia were also identified in various species.