Class-Gastropoda

__Class Gastropoda The Number Giants__

Although small in size, gastropods make up about 80% of the entire Mollusca phylum. Gastropods include snails and slugs. The word "gastropod" comes from the Greek "gaster" for "stomach", and "poda" for "foot", due to early human belief that snails/slugs crawled on their stomachs.

__The Gastropods:__ __Periwinkle Snails__: Periwinkles are small snails found in the Northeastern Atlantic Ocean regions, around Spain, Scotland, etc.

__Sea Slugs__: Sea slugs belong to the clade Nudibranch, deriving from the Latin "nudus", meaning "naked", and "brankhia", meaning "gills". Sea slugs are found in seas all over the earth. Sea slugs are generally brightly colored, either as a warning to predators or as camouflage with plants. The headshield slug, shown here, is a member of the subclass opistobranchia. Unlike some slugs, the headshield slug actually has a shell, although it cannot retreat into the shell entirely. Headshield slugs distinct with a bubble-like shell. They also have headshields to prevent sand from getting inside.

__LIFE STYLE__: __Locomotion__ Both snails and slugs move on their feet, contrary to popular belief. Instead of being at their feet, the stomachs on snails and slugs are hidden at the dorsal side of their bodies. __Feeding__ The common periwinkle snail has a radula inside their mouth that they use to scrape off algae from rocks, or cord grass (in salt marshes), or biofilms (estuarine bays). Headshield slugs are generally herbivores, usually eating algae; however, some are carnivores, going out to even eating other slugs, slug eggs, and some worms. Some slugs are able to track their prey's mucous trails to attack them. __Reproduction__ -Snails are dioecious, and are separated into male and female snails. They reproduce sexually. -Slugs are different; they are hermaphrodites with a very interesting form of reproduction. Once a slug has found a mate, they encircle each other and proceed to mate. They enter their penis in a cork-screwing motion into the mate's genitalia in a process called apophallation. After they exchange sperm, the slugs chew off their penises. But even after the removal of the male rep. system, the slugs are still able to mate with their female counterparts. A pair of slugs mating.

__Fun Facts__ -Periwinkle snails are sometimes used as bait-fishermen crush up their shells and hook them to lure fish. -Slugs mate in an interesting, yet VERY delicate kind of way. -In cuisine studies, 80% of a snail is water, 15% protein, and 1.4% fat.