Question

Which of the following set of animals exhibits cutaneous respiration?
a. Grasshopper and cockroach
b. Fish and snake
c. Caterpillars and tadpole
d. Earthworm and fish

Answer 1

Hint: Cutaneous respiration is the form respiration which occurs mainly for the exchange of gases, and this exchange also occurs through skin or outer integument, Unlike in other animals, which occur through gills and lungs.

Complete answer:
In earthworms the respiration mainly occurred or performed through skin the called as cutaneous respiration.
In this organism, generally the skin is moist and it is only the organ, that helps in respiration, as the true respiratory system is absent.

The earthworm skin is usually supplied by rich blood vessels, whereas In the earthworm, the respiratory pigment is dissolved in the plasma of the blood, which is not like other organisms, and the hemoglobin is responsible for the gaseous exchange.

In the earthworm, skin is always moist and it is because of the presence of mucous and coelomic fluid in the body, and it normally comes through the dorsal pores and makes the skin moist.

The diffusion of gases such as oxygen and carbon dioxide also takes place through the skin, where oxygen generally diffuses into a thin water layer that is present below the mucous layer, and from where it diffuses to the blood, and the carbon dioxide diffusion also occurs in the similar pattern.

Fish: Cutaneous respiration occurs in the Some marine, freshwater and intertidal fishes, though fishes have gills for respiration, sometimes it happens through skin, out of total, 5 to 40% of respiration is by cutaneous.

Hence, the correct answer is option (D).

Note: Though gills are there in many fishes, they have capability to breath through skin because, during development or in early stages, they won’t possess any respiratory organs, where the respiration occurs through skin, and later specific organs developed.