Question

give two reasons why there is no need for the eggs of these fish to be covered by a hard or leathery shell​

Answer 1

Answer:

The egg of fish is surrounded by a jelly-like membrane but does not develop a hard shell. Some fishes lay an egg that is covered by a hard leathery coat.

Answer 2

The major reason why the eggs of fishes lack hard or leathery shells is because of the fusion of sperm and contains nutrients.

1. Promotes fusion: The jelly-like substances present in the outside of the egg promote the sperm to be attracted towards the egg for fusion. It also prevents the fusion of not more than one sperm.
2. Nutrients: After the fusion, the jelly-like substances provide enough nutrients for the embryo to completely develop into an adult, and therefore, fishes do not require hard shells for protection.

• Therefore, unlike birds' eggs that form a hard shell after fertilization, in the case of fishes, the necessity for the formation is not required as it helps in the process of fusion and providing nutrition.