The World Around Us!

Mullusks are bilateral, they can live in land and are snail like and have what is called a foot or they can live in the sea and have jet propulsion using their tentacles. They have two pairs of nerve cords in their nervous system. In their excretory system they have tubular nephridia also known as kidneys, they collect liquid waste and dump through in the shell if it has one. Their digestive system is one way system. Their circulatory system it is a open system that pumps blood into the hemocoel or back. This is pumped by a heart cavity. Their respiratory system on land is done by the mantle cavity lined with blood while at sea they breath using comb gills. Comb gills are tubes that allow water to go in and out. they have no skeleton but some have a outer shell or a inner shell like the squid.