Question

Proteins requirements are generally lower for ....................

• A. Herbivorous fish
• B. Predatory fish
• C. Carnivorous fish
• D. None of the above statement is true

Hint:

Trophic level determines diet cost: herbivorous species (like Grass carp) are cheaper to feed because they require lower protein feeds.
Carnivorous species (like Trout or Catfish) require expensive, high-protein fishmeal-based feeds.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Dietary protein requirements in fish vary according to their feeding habits, trophic status, digestive physiology, and life stage.

Step 2: Detailed Explanation:
Fishes are classified as carnivores, omnivores, or herbivores based on their natural diets:
- Carnivorous and Predatory fishes: Feed on animal matter (such as other fish and insects), which is rich in protein.
Their digestive tracts are short and adapted for rapid, protein-heavy digestion.
They require high dietary protein levels, typically around 40% to 50%.
- Herbivorous fishes: Feed on plant material, algae, and organic detritus.
Plants are lower in digestible protein and rich in carbohydrates.
Herbivorous fishes have longer digestive tracts with specialized microflora to digest complex plant carbohydrates.
Consequently, their dietary protein requirement is lower, typically ranging from 25% to 30%.

Step 3: Final Answer:
Protein requirements are generally lower for Herbivorous fish.