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.

Answer: C. Earthworms (1), Millipedes (3), and Woodlice (5) are detritivores. DETRITIVORES are organisms that consume DETRITUS — dead plant material, decomposing animal matter, faeces, and other organic debris. They are critical for nutrient recycling in ecosystems and are distinct from decomposers (bacteria, fungi) which work on dissolved nutrients. (1) EARTHWORMS — CORRECT. Earthworms ingest soil rich in dead leaves, roots, and organic matter; they fragment and digest detritus, releasing nutrient-rich castings. They are the prototypical soil detritivores. Charles Darwin's last book was on earthworms' role in soil formation. (2) JELLYFISH — WRONG. Jellyfish are CARNIVOROUS PLANKTONIC PREDATORS. They use stinging tentacles to capture zooplankton, small fish, fish eggs etc. They do NOT consume detritus as their primary diet. (3) MILLIPEDES — CORRECT. Millipedes are TERRESTRIAL ARTHROPODS that feed on DECAYING PLANT MATERIAL — leaf litter, decaying wood. They are major detritivores of forest floors, breaking down leaves and contributing to soil formation. (Centipedes, in contrast, are predators.) (4) SEAHORSES — WRONG. Seahorses are MARINE PREDATORS that feed on small crustaceans (copepods, amphipods, mysids) by snapping them up with their tubular snouts. Not detritivores. (5) WOODLICE — CORRECT. Woodlice (also called pill bugs, sow bugs, isopods) are TERRESTRIAL CRUSTACEANS that feed on DECAYING PLANT MATERIAL, fungi, and dead wood. They are important detritivores in temperate ecosystems, often found under logs and leaf litter. So 1, 3, 5 are detritivores; 2 and 4 are carnivores. Source: NCERT Class 12 Biology Chapter 'Ecosystem' (food chains and decomposition).