| |
- Gastropods are a group of Mollusks that includes Snails, Slugs, Limpets, and relatives.
- All of them have a mantle, a fold of skin that covers part of the body like a horse blanket.
- The mantle secrets a shell made of calcium and carbonate.
- Some gastropods use the shell as a shield, some as shelter, some had one and lost it.
- The gastropods with a shelter-like shell have twisted their internal organs. So now the gut and the nervous system look like an U.
- In some gastropods the mantle forms a tube called the siphon, which they use to pump water inside their body.
- Almost all mollusks have ctenidia, a primitive version of fish gills. They look like tentacles. The exception are terrestrial snails, whose mantle has developed a chamber similar to a lung.
- All gastropods have a radula, a trunk like mouth with a tongue full of teeth that they use to rasp their food.
- All gastropods have a foot, used to move, dig burrows, and stick around the floor.
- They can have tentacles on their heads, used them for senses like vision and balance.
- Mollusks bodies are supported by the internal pressure of water. Controlling this water, they can expand and contract their bodies.
 |
|
 |
.gif)
