📘 Q.10 IAS Prelims 2021 — Environment & Ecology (Detritivores)🧷 Authentic Classroom Explanation by IAS Monk
📌 The Question:
Which of the following are detritivores?
- Earthworms
- Jellyfish
- Millipedes
- Seahorses
- Woodlice
Select the correct answer using the code given below:
(a) 1, 2 and 4 only
(b) 2, 3, 4 and 5 only
(c) 1, 3 and 5 only
(d) 1, 2, 3, 4 and 5
✅ Correct Answer: (c) 1, 3 and 5 only
🧠 Classroom Explanation:
🔹 Detritivores are organisms that feed on dead and decaying organic matter (detritus) and help in decomposition and nutrient recycling.
✔ Earthworms — classic soil detritivores; ingest decaying plant matter and enrich soil
✔ Millipedes — feed on decaying leaves and organic debris
✔ Woodlice — consume decomposing plant material and aid humus formation
❌ Jellyfish — carnivorous, feed on zooplankton and small fish
❌ Seahorses — secondary consumers; feed on plankton and small crustaceans by suction feeding
Hence, only 1, 3 and 5 qualify as detritivores.
🔍 Curiosity Raiser:
🌍 Why are detritivores called the “silent recyclers” of ecosystems?
Because without them, nutrients would remain locked in dead matter, choking productivity.
📚 Enrich Notes (Exam Edge):
• Detritivores ≠ Decomposers
- Detritivores → ingest organic matter (earthworms, millipedes)
- Decomposers → chemically break it down (bacteria, fungi)
• Food Chain Position:
👉 Detritus → Detritivores → Decomposers → Nutrient pool
• UPSC Favorite Trick:
- Soil-dwellers + leaf litter feeders → likely detritivores
- Marine gelatinous animals → usually NOT
🪶 IAS Monk Whisper:
When life ends, detritivores quietly begin the next cycle.
