By: Sara smith
Some invertebrates are :
Characteristics of a sponge
* Adult sponges are attached to hard surfaces they can not move.
* Water currents carry food and oxygen to them and take away their waste.
* Pores- water moves into central cavity of the sponge through pores all over the sponges body.
* Collar cell- whiplike structures that move back and forth to push water through the sponge and traps food.
* Spicules (spikes)- they have no skeleton, but a system of a spikes that keep sponges very hard.
* During asexual reproduction small new sponges grow from the sides of the adult sponge.
* When they fall off they begin their own life.
* Sponges also have sperm and eggs cell, so they can complete sexual reproduction.
These are also some invertebrates.
* Central body cavity
* Bodies have radial symmetry (symmetrical around a central point.)
The two different types of Body structures.
Characteristics of worm
* All worms have to tissue, origans, and body systems.
* Worms are the simplest organisms with a brain. There brain is a knot of nerve tissue located in its head end, because of this the worm can detect objects, food, mates and predators quickly
* Some worms have members of both genders (male and female).
* Other worms have both male and female sex organs, but usually don't fertilize their own eggs.
* Some reproduce asexually breaking into pieces.
Characteristics of flat worms
* Many flatworms are parasites. Parasites are organisms that live inside another. Others are free living ( not in another organism) in ponds and oceans.
* It takes food in and gets rid of wastes through the same opening.
Characteristics of round worms
* They are more advanced than flatworms, with thin round bodies and digestive system that opens at both ends.
* Roundworms live in salt water, fresh water, and the soil (even in Antarctic sands). Many of them are harmful to man as they are parasites.
Characteristics of segmented worms
* Segmented worms have bodies made up of many linked sections called segmented.
* Segmented worms have nerve tissue and digestive tract that runs the length of the worm's body with a mouth and anus. A closed circulatory system, meaning blood moves within blood vessels. Blood carries oxygen and food to cells.
Characteristics all mollusks share.
* Thin layer of tissue called the "foot" is used for movement.
* Bilateral symmetry (same on both sides).
* Mollusks that live under the water have gills.
3 major groups:
Characteristics of Gastropods
* Can have a shell or no shell
* Can be herbivores or carnivores.
* Move by creeping along on a broad foot which can ooze mucus.
Characteristics of bivalves
* Clams can move! They even dig into the sand.
* Oysters can form a pearl when a grain of sand enters the shell.
Characteristics of cephalopods
* Capture prey with their tentacles suckers on the tentacles taste and touch.
* Large eyes for good vision.
* Large brains and can remember things they have learned, some have even escaped captivity!
* Swim by jet propulsion ( current of water).