INVERTEBRATES AMAZONIAN GIANT CENTIPEDE INVERTEBRATES ANIMALS WITHOUT A

INVERTEBRATES AMAZONIAN GIANT CENTIPEDE

INVERTEBRATES • ANIMALS WITHOUT A BACKBONE! • 96% of ALL animals are invertebrates • Largest group of invertebrates are the arthropods (insects, arachnids, crustaceans) • Scientists look at SYMMETRY to classify each organism

Invertebrates: Symmetry Radial symmetry: body parts are arranged around in a circle around a central point (starfish). Bilateral symmetry: have two sides that will match if you draw a line down the center of their body (lobster). Asymmetric: these animals have no definite shape at all (sponges).

INVERTEBRATES- SPONGES • Very simple animals • Have many pores (holes) through which water flows • Sponges obtain their food and eliminate wastes through this passage of water • Live in fresh or salt water

ANNELIDS (PHYLUM: ANNELIDA) • Bilaterally symmetrical • Have long tube-like bodies that are divided into segments • Simplest organisms with a true nervous system • Have a long digestive tube that runs down the length of the worm’s body • Examples: earthworms, leeches and sandworms

INVERTEBRATES- ECHINODERMS • Similar parts (arms) that extend from the middle body outwards • They have feet and spines • Examples: starfish, brittle stars, sea cucumbers, or sea urchins

INVERTEBRATES- ARTHROPODS • Have jointed legs • Live on land in water • Have hard outer coverings called exoskeletons • Have segmented bodies and some have wings • Examples: insects, spiders, and crustaceans

INVERTEBRATES- MOLLUSKS • Have soft bodies • Most have a thick muscular foot for movement or to open and close their shells • Live in salt or fresh water or on land • Some have shells • Examples: snails, clams and octopi

Invertebrates- Cnidarians • Aquatic • Some have stinging tentacles around their mouths that they use to catch food and for defense • Ex: Jellyfish