Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Anemonefish is categorised as protandrous hermaphrodite.
Reason R: Anemonefish is born male first and then changes its sex to female during its life span.

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true but R is NOT the correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Hint:

Sex change in fish:
1. Protandry: Male to Female (e.g., Anemonefish, Lates calcarifer).
2. Protogyny: Female to Male (e.g., Groupers, Wrasses).
"Andry" relates to males (Androgens), "Gyny" relates to females (Gynecology).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
This question deals with sequential hermaphroditism in marine fishes, specifically in the Anemonefish (Clownfish, Genus Amphiprion).
Detailed Explanation:

• Protandry: Protandry is a form of sequential hermaphroditism where an organism begins its life as a male and later changes its sex to female. The term "proto" means first and "andros" means male.

• Anemonefish Social Structure: In a colony of anemonefish living within a sea anemone, there is a strict hierarchy. There is one large dominant female, one smaller breeding male, and several non-breeding juveniles/males.

• Sex Change Process: All anemonefish are born as males. If the dominant female dies, the breeding male undergoes a hormonal shift and changes its sex to become the new dominant female. One of the larger juveniles then matures to become the new breeding male. This confirms both Assertion A and Reason R.

• Relationship between A and R: Reason R defines what protandrous hermaphroditism is in the context of anemonefish. Therefore, it provides the correct explanation for why they are categorized as such.

Step 2: Final Answer:
Both statements are true, and the reason correctly explains the assertion.