Mollusca is a phylum of invertebrate – that is to say without a skeleton – animals. this group consists of no less than 85,000 species and has been here for a very long time. So long that in addition to this staggering amount of recognized species, there are around 100,000 fossils of extinct mollusks species.
Most of the Mollusca dwell at sea where gravity has little effect. There some of them – like the giant squid – can reach a staggering size of 43ft (13m) and a weight of 1500 pounds (700kg) without any bone support.