Gastropoda – Snails & Slugs
The Gastropoda are the most species-rich class of the Mollusca and have an incredible variety of colours and shapes. Estimations vary from 40,000 to more than 200,000 species worldwide.
The main difference between Gastropoda and other molluscs is the asymmetrical body. It consists of a head, foot and an intestinal sac. The housing consists of lime, which is absorbed with the food, and is more or less degenerated in many species. Some snails have a housing, but they can not use it as a retreat because of its small size.
The diet takes place with an organ that is unique in the animal kingdom and exists only within the molluscs. The radula, a rasp tongue with many teeth, is used to eat.
Habitat and Distribution
Gastropoda live all over the globe. They occur both, in fresh and salt water, and many of them live ashore. By the way, they represent the only class of molluscs that has also produced land creatures.
Gastropoda are also not selective in their habitat underwater. Snails inhabit reefs, sandy soil, tide pools and some even the open water. In the Canary Islands they are mostly found at night on lava rocks, but also on sandy surfaces and in caves. The best time to observe Gastropoda is the spring, when the water is coldest. At this time we can observe most eggs as well.