Step 1: Understanding the Question:
The question asks about the physical appearance of carp eggs (like Rohu, Catla, Mrigal) shortly after successful fertilization and water hardening.
Detailed Explanation:
• Changes After Fertilization: Unfertilized eggs are usually slightly yellowish and somewhat cloudy. Once an egg is fertilized, it absorbs water (water hardening) and the perivitelline space expands.
• Appearance: Healthy, viable, and fertilized carp eggs are transparent and clear. This transparency allows for the observation of the developing embryo inside during the incubation period.
• Significance of Transparency: Transparency is a vital indicator of egg quality for hatchery managers. If an egg appears white or opaque, it usually indicates that the egg is dead, unfertilized, or infected with fungus (like Saprolegnia).
• Egg Type: Most Indian Major Carp (IMC) eggs are non-adhesive and semi-buoyant in nature. They swell to several times their original size after being spawned in water.
Step 2: Final Answer:
Fertilized, viable carp eggs are transparent.