invertebrates most animals in the world are invertebrates these are animal without a backbone
TRANSCRIPT
Invertebrates• Most animals in the world are invertebrates
• These are animal without a backbone
Groups
The most common groups of Invertebrates are:1. Arthropods2. Protozoa3. Annelids4. Echinoderms5. Mollusks
Many invertebrates have a fluid filled skeleton, likea worm or a jellyfish.Others have a hard outer shell like crustaceans (crabs)and insects (spiders).
ArthropodsArthropods include:
• Insects
• Arachnids
• Crustaceans
Arthropods: Insects• Insects are the largest group of arthropods.
• They are very adaptable which means they can live almost anywhere in the world.
• They have an exoskeleton which serves mainly as a protective covering.
• An insects body consists of 3 parts: head, thorax and abdomen
Arthropods: InsectsMore characteristics of insects:• pair of antennae• compound eyes• have legs• some have wings
Compound eyes in the head of a crane fly
ArachnidsCharacteristics:• spiders, scorpions, ticks and mites• do NOT have antennae• exoskeleton• have many legs• scorpions are the largest arachnid group
spider scorpion tick mites
CrustaceansCharacteristics:• Most common are the crab, lobster and barnacle• Live mostly in the ocean or other waters• Have a hard, external shell that protects their body• Have a head and abdomen• Their head has antennae• Have legs• Some have claws
crab lobster barnacle
Protozoa• Protozoa are single celled animals• Most are extremely tiny (microscopic)• consume(eat) bacteria• Two main types: amoebas, flagellates
flagellate
amoeba
Annelids• Annelids have bodies that are divided into segments (parts).• They have bristles (like legs). Some have short ones (earthworms) others have long ones.• They have very well-developed internal organs, so it’s easy for them to move around on the ground.• There are about 9,000 of known annelids.• lugworms, clam worms, bristle worms, fire worms, sea mice
Echinoderms• These animals live in the ocean• They have arms or spines that start at the center of their body• The center part of their body contains their organs and their mouth• The spines often protect them from predators• Examples are: star fish (sea stars), sea urchins, sea cucumbers
Sea urchin Sea stars
Sea cucumber
Mollusks• Most mollusks have a soft sin-like organ on the inside and a hard shell on the outside• Some mollusks live on land and others in the water• Examples of mollusks that live on land:• snails and slugs• Examples of mollusks that live in the water:• oyster, mussel, clam, squid, octopus
oyster mussel clam squid octopus
Mollusks
• Land mollusks have a soft “foot” that helps them move—but they move very slowly• Water mollusks propel themselves in the water by ejecting water from their bodies• Some mollusks, like the oyster, attach themselves to rocks and Feed from the food particles