Скачать или смотреть respiration of multicular organism |respiration in earthworm and aquatic animal

The earthworm exchanges the gases through its skin.
This means that the respiratory surface of an earthworm is its skin.
The skin of an earthworm is quite thin and moist, and has a good blood supply.
So, the earthworm absorbs the oxygen needed for respiration through its moist skin.
This oxygen is then transported to all the cells of the earthworm by its blood where it is used in respiration.
The carbon dioxide produced during respiration is carried back by the blood.
This carbon dioxide is expelled from the body of the earthworm through its skin.
Thus, in earthworm, gaseous exchange takes place through the skin which is thin and moist .
Just like earthworms, the leeches also absorb the oxygen needed for respiration through their skin .
And carbon dioxide produced inside the leeches (during respiration) also goes out through the skin.
The fish has special organs of breathing called ‘gills’. The fish has gills on both the sides of its head .
The gills are covered by gill covers so they are not visible from outside.
The fish lives in water and this water contains dissolved oxygen in it.
For breathing, the fish uses the oxygen which is dissolved in water.
The fish breathes by taking in water through its mouth and sending it over the gills .
When water passes over the gills, the gills extract dissolved oxygen from this water.
The water then goes out through the gill slits (hidden under the gill cover).
Thus, the dissolved oxygen is extracted from water by the fish when it flows over the gills.
The extracted oxygen is absorbed by the blood and carried to all the parts of the fish.
The carbon dioxide produced by respiration is brought back by the blood into the gills for expelling into the surrounding water.
The fish has no lungs like us, the gaseous exchange in fish takes place in the gills.
So, the respiratory surface of a fish is the surface of its gills
when a fish is taken out from water it dies soon (even though there is a lot of oxygen in the air around it).
This is because a fish does not have lungs to utilise the oxygen of air for breathing and respiration.
The fish has gills which can extract only dissolved oxygen from water and provide it to fish.
Gills cannot take in the oxygen from air on land.
Since fish does not get oxygen for breathing when taken out of water, it dies.
In addition to fish, many other aquatic animals like prawns and mussels also have special organs called ‘gills’ for breathing and respiration.
The fish exchanges the gases by using its special organs called ‘gills’ whereas the earthworm exchanges the gases through its thin and moist ‘skin’.