As you already know, all animals need oxygen to live (oxygen and nutrients make energy), and they expel carbon dioxide.

But animals have different ways of taking oxygen. Let's study them!!

MAMMALS, BIRDS AND REPTILES

All of them use their lungs to breathe in oxygen and breathe out carbon dioxide. The process is the same as in humans.


Lungs.jpg

FISH

Fish don't have lungs, they breathe through their gills: fish take water with their mouths. Water passes through their gills and the gills absorb the oxygen from the water. Then, the water leaves the fish's body.


Gills.jpg

Red Gills.jpg
FISH USE THEIR GILLS TO OBTAIN OXYGEN


AMPHIBIANS

Amphibians are very special animals:

  • When amphibians are babies, they breathe with their gills.



Young Salamander.jpg
BABY SALAMANDERS BREATHE WITH THEIR GILLS
  • When amphibians are adults, they breathe with their lungs.


Adult Salamander.jpg
ADULT SALAMANDERS BREATHE WITH THEIR LUNGS

  • Some amphibians can also breathe through their skin.


Frog - Amphibian.jpg
FROGS CAN BREATHE THROUGH THEIR SKIN

INVERTEBRATES

Depending on the species, invertebrates can breathe using "simple" lungs (very elementary and primitive lungs), gills or through their skin.


Spiders - Breathing.jpg
SPIDERS USE PRIMITIVE LUNGS TO BREATHE

Clam - Breathing.jpg
CLAMS USE GILLS TO BREATHE

Worm - Breathing.jpg
WORMS USE THEIR SKIN TO BREATHE

Time for the videos.

The first video is about how gills work (how fish breathe under water).



The second video is about how frogs use their lungs and their skin to breathe.