A Comparative Study of Venom Apparatus Structure in Cone Snail (Conus textile)by Hematoxylin-Eosin and Greenlight

Cone snails of the genus Conus are highly regarded for their medicinal compounds derived from their toxins. In order to examine the venom apparatus structure, 12 specimens of C. textile were collected from the coastal zone of Gheshm Island and fixed in Bouin's for 48 hours and transferred to laboratory in ethanol. After breaking of shellfish, the venom apparatus were isolated and their different parts (after molding and cutting) were stained by HE and HEG and photographed by Nikon microscope. The stereomicroscope observation showed that the venom apparatus consisted of (1) toxin production part (venom duct), (2) toxin transmission part (venom bulb), and (3) injection part (radula and proposcis). Photographs of sections showed that the venom bulb was completely muscular, consisting of longitudinal and transverse muscle fibers, and in their middle part a channel with epithelial cells was observed. Venom duct walls composed of 3 parts including the outer layer of muscle an inner layer of columnar epithelial cells with basal nucleus and the inner lumens which filled by the granules. HEG stained slides showed a much sharper cytoplasmic and nuclear implementation, particularly granules containing toxins were easily countable and measurable. Although the onventional HE staining method clearly showed different parts of the gland, but HEG method in addition to distinguishing different sections of tissue, seemed to be a suitable technique for studying the role of different parts of the organ in producing conotoxin in the form of secretory granules.