Match the following columns and select the correct option. Column - I Column - II (a) 6-15 pairs of gill slits (i) Trygon (b) Heterocercal caudal fin (ii) Cyclostomes (c) Air Bladder (iii) Chondrichthyes (d) Poison sting (iv) Osteichthyes
Trygon - A fish possessing a poison sting is Trygon (e.g. sting-ray).
Cyclostomes - They have 6-15 pairs of gill slits.
Chondrichthyes - They are the cartilaginous fish with heterocercal caudal fins (e.g. sharks).
Osteichthyes - They are the bony fish having air or gas bladder that helps in controlling the buoyancy, this in turn helps to stay at their current water depth without having to waste energy in swimming.
Thus, the correct answer is (D).
Which of the following is/are not the characteristics of the class Osteichthyes? (i) The body is streamlined and mouth is terminal. (ii) Gills are covered by an operculum. (iii) Skin covered with cycloid and placoid scales. (iv) Many of them are viviparous.
Which of the following is a correct match?
Which one of the following categories of animals, is correctly described with no single exception in it?
Pelvic claspers are found in
Hippocampus is called as 'sea horse', becuase