The Foregut Glands of Vermivorous Cone Shells

Salivary, snout, and secondary salivary glands are recorded in the foregut region of Conus Javidus, C. lividus, C. litteratus, C. miles, C. vexillum, and C. virgo. C. imperialis has a salivary gland only. The histology and histochemistry of these glands in C. Javidus and C, lividus is investigated. The salivary gland secretion consists of granules composed of polysaccharide and protein. The snout gland secretes sulphated acid mucosubstances. The secondary salivary gland secretion contains polysaccharide and protein. Protease activity was detected histochemically in the salivary gland, indicating that a function of this gland in Conus is the secretion of proteolytic enzymes into the short arm of the radular sac. The functions of the snout gland, which is peculiar to some species of Conus, and of the secondary salivary gland, which occurs sporadically throughout the Stenoglossidae, are not immediately apparent. The marine gastropod family Conidae is well represented in Australian waters, particularly on the Great Barrier Reef. All species are thought to possess a venom apparatus used in the capture of prey. Kohn (19.59~) has shown that within the genus three groups can be distinguished on the basis of feeding habits. Most feed on marine worms, mainly polychaetes, while the second group feeds on fishes and the third on other gastropods. Only three papers on the anatomy and histology of the venom apparatus and associated structures in Conus deal with vermivorous species. Bergh (1896) examined 33 species of Conus, Alpers (1931) studied C. lividus Hwass in Bruguibre, and Martoja (1960) C. mediterra~eus Bruguikre. The results of Alpers and Bergh differ considerably, possibly because they used material which had been preserved for several years. However, both these authors describe certain foregut glands which have not otherwise been recorded in Conus. My preliminary dissections demonstrated the presence of these glands in some local Australian vermivorous species. Detailed anatomical, histological, and histochemical studies were made on the foregut glands of locally obtainable vermivorous Conus in an attempt to elucidate their homologies, structure, and function. This paper deals with the snout, salivary, and secondary salivary glands. The venom gland will be discussed in a subsequent