Tuesday, March 16, 2010

Gastropod facts

Gastropods are snails and slugs, so Gastropods have one or no shell. Slugs and snails have a broad foot on the bottom thats how they get there name. Gastropods means broad foot. Gastropods eat anything from leaves to meat. Gastropods can live almost anywhere they live in the water as long as on land and on treetops. Gastropods have a trapdoor on there foot and when the weather is dry they close there trapdoor and stay in there. Then they wait till the weather is moist then they open there trapdoor. Snails can live a long time while in there shells without food or water. One day scientists brought a snail that was assumed to be dead, but when they put the snails in water one of them crawled away.

Mollusks Characteristics

Mollusks can be clams, oysters, and scallops are all examples of mollusks. Mollusks are invertabrates that have soft bodies that is protected by the shell. Mollusks have a thin layer of tissue called the mantle. The mantle covers there internal organs. Most Mollusks have a foot which is a muscular structure. They use there foot for crawling, catching prey, or digging. Mollusks can live inalmost any environment, but usually in water such as the ocean or in lakes. Mollusks can also live on land. There are three main groups of Mollusks they are the gastropods, bivalves, and cephalapods.

Wednesday, March 10, 2010

Skeletons on the Outside

Arthropods are soft on the inside and hard on the outside. There shell (skelleton) is waterproof. This is called an exoskeleton it protects the animal and it helps them
stay dry from evaporation. Water animals don't need to worry, but for animals on land this goes into effect. The first kind of speices to move out of water was the Arthropod and that is why Arthropods have shells. The material that the exoskeleton is made of is called a Chitin. The Chitin is made of long molecules that is made of smaller building blocks. Long chain molecules like these are calleds. When the Arthropods get older the exoskeleton dose'nt get bigger once the Arthropod out grows its shell they shed it off.

Tuesday, March 9, 2010

Arthropods Characteristics

Arthropods are mostly bugs like spiders or centipedes. Some of the other Arthropods are crabs and one that some people don't know the horseshoe crab. Even though these animals are all different they have simalar characteristics all Arthropods are phylum they are invertbrates that have a Exoskeleton a segmented body and have jointed parts called appendages. Apendages are legs and hands. Arthropods came from the Greek. Arthros means joint and pods means foot.