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. ​

The correct answer is C (1, 3 and 5 only). Detritivores feed on dead organic matter, or detritus, and fragment it so that decomposers such as fungi and bacteria can finish the job of mineralisation.

• Earthworms (1): detritivores. They ingest soil rich in decaying leaf litter and organic matter, which improves soil structure and nutrient cycling.
• Millipedes (3): detritivores. They feed on decaying leaves and other dead plant material on the forest floor.
• Woodlice (5): detritivores. These terrestrial isopods consume dead and decaying plant matter.
• Jellyfish (2): wrong. They are carnivores that capture zooplankton and small fish with nematocyst-armed tentacles.
• Seahorses (4): wrong. They are carnivores that suck up small crustaceans such as copepods and mysids through the snout.

The concept links to the ecology unit on food chains and nutrient cycles. For Mains, it connects to soil health, vermicomposting and organic farming, where earthworms are the practical application.

Trap: assuming that any animal living in soil or leaf litter is a detritivore, or that seahorses feed on organic debris.