Question

Best live feed for carp spawn in the nurseries is

• A. Rotifers
• B. Diatoms
• C. Spirulina
• D. Dinoflagellates

Hint:

Carp Spawn Live Feed Succession: First 3--5 Days = ROTIFERS (Brachionus) $\rightarrow$ Next 5--15 Days = CLADOCERANS (Moina, Daphnia) $\rightarrow$ Advanced Fry = Supplementary artificial mash.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Carp nursery feeding and larval gape size limitations: microscopic, slow-swimming zooplankters like rotifers (Brachionus spp.) match the 100--250 $\mu$m mouth gape of 3-day-old carp spawn.

Step 2: Detailed Explanation:
In freshwater carp nursery management:
- Newly hatched carp larvae absorb their yolk sac within 72 hours, transforming into free-swimming Spawn ($5 - 6\text{ mm}$ length) with a tiny mouth gape ($< 150 - 200\;\mu\text{m}$).
- Rotifers (such as Brachionus rubens, Brachionus plicatilis, and Keratella) are the best and most ideal initial live food because:
1. Their microscopic size ($100 - 200\;\mu\text{m}$) fits the small mouth gape perfectly.
2. Slow ciliary locomotion allows easy capture by weak-swimming carp spawn.
3. They provide high protein content ($50 - 65\%$) and essential enzymes that trigger early digestion before larger cladocerans (Moina, Daphnia) can be ingested.

Step 3: Final Answer:
Thus, the best live feed for carp spawn is Rotifers, corresponding to option (A).