Animal SortAnimals Without
BackbonesLesson 57
In our last lesson we learned which animals have backbones. We also learned ways to sort animals with backbones. We learned we can
sort them into five groups: amphibians, reptiles, mammals,
birds and fish.
Today we will learn about the many animals which do not have
backbones.
There are more animals without backbones than with backbones.
Some animals without backbones have shells or hard body coverings.
This helps them stay safe.
Some animals without backbones have no shells. They have soft
bodies. These animals must use other ways to stay safe.
Let’s make a list of animals without backbones who have
hard outer shells.
Snails have no backbones and they carry a hard shell around on their back for protection. The shell
is the snail’s home.
Snails move along on one wide, slimy foot. To hide from enemies the snail can pull its body into the
shell. Snail’s eat plants.
Here is a video of a snail walking.
• https://www.youtube.com/watch?v=8crNeMGd_l4
Spiders do not have
backbones but have a
hard covering on their body.
Spiders have 8 legs.
Spiders make webs to catch their food. Spiders are meat eaters.
They eat insects.
Here is a video of a spider spinning its web.
• https://www.youtube.com/watch?v=g5iN0ZaoW7M
Lobsters do not have backbones but have hard shells. Lobsters are meat
eaters. They live in the ocean. Lobsters eat fish, crabs and clams.
Here is a glimpse of a lobster underwater.
• https://www.youtube.com/watch?v=Lj0ecgBvSwo
Let’s make a list of animals without backbones who have no
hard outer shells.
Jellyfish do not have backbones and do not have a hard
outer shell to protect themselves. Instead
they can sting enemies with their
tentacles.
Jellyfish eat fish and live in water. Here is a video of a jelly fish
swimming.
https://www.youtube.com/watch?v=GTXinF8ZVCo
Centipedes do not have backbones but do have a hard outer shell. Centipedes have
around 30 legs.
Centipedes are plant eaters and meat eaters. They eat insects and
spiders.
Here is a video of a centipede eating a spider.
• https://www.youtube.com/watch?v=BMwHqNWFOZk
Earthworms have no backbones and have no hard outer shells to
protect themselves. Earth worms also do not have legs.
Earthworms eat plants and plant materials in the soil. Earthworms
help soil.
This video shows how earthworms move.
• https://www.youtube.com/watch?v=_mba2COlUOg
Today we learned about a few living things that do not have
backbones. Some of the living things have hard outer shells and
some do not.
In our next lesson we will review what we have learned in Unit 5
Animals and Plants are Living Things.
Keep observing the world around you!