Invertebrates

Animals of all kinds

Sponges

Sponge - one type of animal that filters the water it lives in to get food.

Example - Venus-Flower Basket,


Characteristics

- reproduce asexually

- can’t move

- gets food from environment around it.

- between inner and outer layer there is a jelly-like layer

- grow at almost any depth

- grow on hard surfaces

- shaped like fingers, tree branches or round

- filters water to get its food

- 5000 known species

-no real digestive system


Adaptation - body is a network of tiny pores and canals that allow water to filter through to obtain food because they don’t move.



Arthropods

arthropod - An animal that has a jointed exoskeleton and jointed limbs

Crustaceans - A kind of arthropod with three body segments such as a lobster that has a head, thorax, and an abdomen.


arachnids - An arthropod such as a spider that contain 8 legs and no antennae


Insects - An arthropod such as a grasshopper that are the largest group with six jointed legs


Characteristics

- Has legs

- A digestive system with two openings

- A circulatory system

- Has a brain



Adaptations

Muscles attached to the inside of the exoskeleton contract and relax which allows for complex movements.


How do arthropods help people?

- Are a food source for other animals

- Some Arthropods such as bees produce wax and honey

- Many pollinate flowers

- Help other animals reproduce

- Eat insects that destroy crops or flowers






Echinoderms

Echinoderms - are invertebrates that have internal skeletons and spines sticking out from their bodies

examples: starfish, sand dollars, sea urchins, sea cucumbers


Characteristics

Interval skeletons and spines

live only in the ocean

get oxygen from seawater

most adults appear to have radial symmetry

spiny skin

endoskeleton

no head or brain

tube feet


Adaptation - Mouth is at the center of underside with powerful jaws and hidden among their spines and poison glands. They also have tube feet for moving, feeding and sensing respiration