3. They are classified into six main groups:
Invertebrates
Molluscs Coelenterates Porifera Echinoderms Arthropods Annelids
4. o Molluscs have soft bodies
o Many molluscs have a hard shell
o Most molluscs absorb oxygen through gills
o They reproduce by laying eggs
Learn more about molluscs at
https://www.youtube.com/watch?v=RIygbucNX-0
Mussels Oysters Giant clams Octopus Slug Snail
Squid
5. o Coelenterates have soft bodies
o Some have long tentacles
o Coelenterates absorb oxygen through their skin
o They reproduce through buds
o Some move freely, other are fixed to the seabed
Polyp Jellyfish Coral Hydra
Learn more about coelenterates at
https://www.youtube.com/watch?v=zxgZoOF3fN0
Jellyfish
6. o Porifera have soft bodies with pores
o They absorb oxygen and nutrients through the pores
o They reproduce through buds
P. CalcareaSponge Porifera CalcareaPorifera SpongePorifera
Learn more about porifera at
https://www.youtube.com/watch?v=laJgUrSsO_k
o They live in salt water
Sponge
7. o Echinoderms have bodies covered with spikes
o Some have arms and tentacles
o Some absorb oxygen through gills
o Others absorb oxygen through their skin
o Echinoderms are oviparous
Learn more about echinoderms at
https://www.youtube.com/watch?v=WYFj9WfBXsA
Sea UrchinStarfish
Sea Urchin
Starfish Feather Star
o They live in salt water
Starfish
8. o Arthropods have an exoskeleton
o They have jointed legs that bend
o Some breath with lungs; others, with gills
o Arthropods are oviparous
o Insects and spiders are arthopods
Learn more about arthropods at
https://www.youtube.com/watch?v=-jNNvjJkLoc
Millipede
Butterfly Hermit crab
Spider
Bee
Scorpio
Beetle
9. o Annelids have a long, soft body divided into rings or segments
o Some breath with gills, others breathe through their skin
o Some annelids reproduce by budding
o Others are oviparous
Learn more about annelids at
https://www.youtube.com/watch?v=9rw5r3PmOMY
https://www.youtube.com/watch?v=cdr1kWmSiiE
Earthworm
Sandworm
Duster worm
Leech
Medicinal leech
Duster
worm