Question

Which of the following fish is a protandrous hermaphrodite?

• A. Tilapia
• B. Asian Seabass
• C. Catla
• D. Cobia

Hint:

Remember the prefixes:
- "Prot-andry" starts as male (andro- = male), e.g., Asian Seabass.
- "Proto-gyny" starts as female (gyno- = female), e.g., Groupers.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Sequential hermaphroditism is a reproductive strategy where an individual changes its sex at some point in its life cycle.
There are two main types:
1. Protandry: The individual begins its life as a male and later transitions into a female.
2. Protogyny: The individual begins its life as a female and later transitions into a male.

Step 2: Detailed Explanation:
The Asian Seabass (Lates calcarifer), also known as Barramundi, is a catadromous species that exhibits protandrous hermaphroditism.
In this species, younger, smaller individuals mature sexually as functional males.
These males generally migrate to brackish or marine estuarine environments to spawn.
As they grow larger and older (typically around 3 to 5 years of age, reaching lengths over 80 cm), they undergo a physiological sex reversal to become functional females.
This sex change is influenced by both age and environmental factors.
Let us review the other options:
- Tilapia: Standard gonochoristic species (separate sexes from birth), though sex can be reversed using hormones during early larval stages.
- Catla: Gonochoristic species.
- Cobia: Gonochoristic species.
Therefore, Asian Seabass is the correct example of a protandrous hermaphrodite.

Step 3: Final Answer:
Asian Seabass is a protandrous hermaphrodite, maturing first as a male and later changing into a female.
Thus, the correct choice is (B).