Different animals have different modes of respiration:

  • Unicellular animals: Diffusion
  • Animals that live inside soil (like Earthworms): Breathe through the skin
  • Aquatic animals: Gills which extract dissolved oxygen in water
  • Insects (like grasshopper, cockroach, housefly, mosquitos): tiny holes called spiracles connected to tubes called tracheae.
  • Lands animals (like humans, birds, lizards) have lungs.


Respiration in Amoeba:

Amoeba lives in water.

  • Water has oxygen dissolved in it.
  • This oxygen diffuses into the body of the amoeba through its cell membrane .
  • The oxygen is used for respiration inside the cell and energy and carbon dioxide are released .
  • Other animals like paramecium and planaria also respire through their cell membranes.

Respiration in Amoeba - Teachoo.jpg

Respiration in Earthworms:

  • Earthworms exchange gases through their skin.
  • The skin is moist, thin and has a good blood supply.
  • The oxygen is absorbed through its moist skin and transported to the rest of the body for use in respiration.
  • Carbon dioxide produced as waste is expelled through its skin .
  • Leeches also respire like earthworms through its skin.

Respiration in Fish:

Fishes have special organs for breathing called gills .

  • Fishes live in water, and water has dissolved oxygen in it.
  • When the water passes through the gills, the gills extract dissolved oxygen from the water.
  • The water goes out through the gill slits.
  • The oxygen is carried with the blood to different parts of its body.
  • Carbon dioxide is brought back by the blood to the gills, which expel it into the surroundings.
  • Gills cannot take in oxygen from the air . So aquatic animals like fishes die when taken out of water.
  • Eg: Prawns, mussels

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Ask a doubt
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 13 years and a teacher from the past 17 years. He teaches Science, Economics, Accounting and English at Teachoo