Which of the following are detritivores? 1. Earthworms 2. Jellyfish 3. Millipedes 4. Seahorses 5. 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 ✓ UPSC's answer
- (d) 1, 2, 3, 4 and 5
Why the answer is (c)
• Detritivores feed on dead organic matter (detritus), breaking it down and speeding nutrient recycling.
• Earthworms (1), millipedes (3) and woodlice (5) eat decaying leaves, wood and soil organic matter — classic detritivores.
• Jellyfish (2) are predators of plankton and small fish; seahorses (4) suck in live copepods and shrimp — both are consumers, not detritivores.
• Detritivores differ from decomposers (fungi, bacteria), which absorb nutrients externally rather than ingesting detritus.
• Hence 1, 3 and 5 only, option (c).
Why the other options are wrong
- (a) 1, 2 and 4 only
- Jellyfish and seahorses are predators, not detritivores.
- (b) 2, 3, 4 and 5 only
- Jellyfish and seahorses are not detritivores; earthworms are.
- (d) 1, 2, 3, 4 and 5
- Jellyfish and seahorses feed on live prey.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2021, held on 10 October 2021. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.