Question

Which one of the following is a natural hermophrodite?

• A. Pearl spot
• B. Tilapia
• C. Pangasius
• D. Sea bass

Hint:

Hermaphroditism in Fish:
1. Protandrous (Male to Female): Sea Bass, Clownfish.
2. Protogynous (Female to Male): Groupers, Wrasses.
Most common aquaculture species are gonochoristic (fixed sex).

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question identifies which of the listed fish species naturally exhibits hermaphroditism (possessing both male and female reproductive organs, either simultaneously or sequentially).
Detailed Explanation:

• Sea Bass (Lates calcarifer): The Asian Sea Bass (or Barramundi) is a protandrous hermaphrodite. This means that individuals typically reach sexual maturity first as males and later undergo a sex change to become females as they grow older and larger.

• Other Options:
• Pearl spot (Etroplus suratensis): Gonochoristic (distinct sexes throughout life).

• Tilapia (Oreochromis spp.): Gonochoristic, though they exhibit plastic sex determination (sex can be reversed artificially).

• Pangasius: Gonochoristic.

• Biological Significance: In Sea Bass, the sex reversal usually occurs when the fish reaches a certain length/weight threshold (often around 3-4 kg). This has significant implications for hatchery management, as large broodstock must be maintained to ensure the presence of females.

Step 3: Final Answer:
Sea bass is the natural hermaphrodite among the given options.