Internal Anatomy

Like all gastropods, the visceral mass of spider conchs undergoes 180⁰ of tortion during primary metamorphasis. The head holds highly ganglionated cerebral organs. The gut is regionalised into the stomach, intestine, rectum and anus. The siphon, which is a projection of the mantle, is folded to allow water to circulate over the long series of gills (ctenidia). Oxygenated haemal fluid is transported by the heart to the head, foot and visceral mass via a limited set of arteries and veins.

Figure 1: Generalised diagram of a gastropod.