Step 1: Understanding the Concept:
Different fish species exhibit highly diverse life-history strategies, which are reflected in their age at first sexual maturity.
Smaller, fast-growing tropical species reach maturity within months, whereas large, slow-growing, or deep-sea cartilaginous and bony fishes can take decades to mature.
Step 2: Detailed Explanation:
Let us analyze the typical age at first maturity for each of the listed fishes under ideal conditions:
1. Tilapia (E): An exceptionally fast-growing tropical cichlid that matures very early, typically within 3 to 6 months of hatching.
2. Indian mackerel (C): A marine pelagic species (Rastrelliger kanagurta) that reaches sexual maturity at approximately 9 to 12 months of age.
3. Rohu (B): An Indian major carp (Labeo rohita) that typically reaches sexual maturity in freshwater environments at around 2 years of age.
4. Sturgeon (D): A primitive, slow-growing bony fish that takes a remarkably long time to mature, typically requiring 5 to 15 years (or more depending on the species and water temperature).
5. Whale shark (A): The largest living fish species (a cartilaginous elasmobranch), which exhibits an extremely slow growth rate and is estimated to reach sexual maturity only at around 25 to 30 years of age.
Arranging these species from the earliest maturity to the latest maturity yields the sequence: (E) Tilapia \(\rightarrow\) (C) Indian mackerel \(\rightarrow\) (B) Rohu \(\rightarrow\) (D) Sturgeon \(\rightarrow\) (A) Whale shark.
This matches the sequence: (E), (C), (B), (D), (A).
Step 4: Final Answer:
The correct sequence is (E), (C), (B), (D), (A).