3. Protozoa
- Protozoa are simple, single-celled animals.
- They are the smallest of all animals.
- Most protozoa are microscopic in size, and can only be
seen under a microscope.
- Protozoa take in oxygen and give off carbon dioxide
through the cell membrane.
4. Annelids
- They have bodies that are divided into segments.
- They have very well-developed internal organs.
- They don't have any limbs.
- They are about 9,000 species
of Annelids
5. Mollusks
• First inhabitants of the Earth.
• Mollusk fossils are usually well preserved
because of their hard shell (over 500 million
years)
• Most mollusks have a soft, skin-like organ
covered with a hard outside shell.
• Some mollusks live on land, such as the snail
and slug.
• Other mollusks live in water, such as the oyster,
mussel, clam, squid and octopus.
6. Echinoderms
- Marine animals that live in the ocean.
- Sea star, Sea Urchin, Sand Dollar and Sea Cucumber.
- Arms or spines that radiate from the center of their body.
- The central body contains their organs, and their mouth for
feeding.
- Sea stars have 5 or more arms attached to their body.
7. Crustaceans
• Crustaceans have a hard, external
shell which protects their body.
• Crustaceans have a head and
abdomen.
• The head has antennae which are
part of their sensory system.
• The abdomen includes the heart,
digestive system and reproductive
system.
8. Arachnids
• Arachnids are a type of arthropod
• Common arachnids are spiders,
scorpions, ticks and mites.
• They have a hard exoskeleton
• Most arachnids have 4 pairs of legs. In
some, the first pair of legs may be used
for holding their prey and feeding.
• Unlike other arthropods, arachnids do
not have antennae.
9. Insects
- Insects are the largest group of arthropods.
- Insects are very adaptable, living almost
everywhere in the world.
- Common insects include the fly, beetle,
butterfly, moth, dragonfly, bee, wasp and
praying mantis.
- Insects have an exoskeleton that covers their
entire body.
- An insect's body consists of 3 parts: the
head, thorax and abdomen.
