Question

Why do fish and frogs produce a huge number of eggs each year?

Answer 1

Hint: Fishes are aquatic animals which belong to phylum Chordata and are devoid of limbs and contain gills in place of lungs. Frogs also belong to phylum Chordata and are classified as amphibians that are capable of living on both land and water.

Complete answer:
Frogs lay eggs in water and their initial stages of development also take place in water during which they have a few characteristics similar to fishes like tail and gills. At this stage they are known as tadpoles. Both fishes and frogs reproduce by means of external fertilization. The female releases the egg in water and the male also releases the sperm in water. The sperm and egg then move close to each other by means of changes in turbulence in water and finally fuse to produce the offspring. But there can be circumstances where the egg and sperm instead of moving in the direction of each other in turn move away from each other or they can be consumed by some predators. In such scenarios the rate of fertilization decreases drastically. So to maintain a constant rate of fertilization large numbers of eggs are produced by frogs and fishes.

Note: In the case of organisms that carry out internal fertilization, a huge number of eggs need not be produced. In this case the sperm enters the female and migrates towards the egg and carries out fertilization. In most cases only a single egg is produced by the female.