UPSC Prelims 2021 Question:

Which one of the following are detritivores?

1. Earthworms
2. Jellyfish
3. Millipedes
4. Seahorses
5. Woodlice
   
   

Select the correct answer using the code given below.

Explanation:

• Detritus means dead plants and animal remains such as leaves, flowers and dead bodies of animals, including fecal matter. Detritivores break down detritus into smaller particles. This process is called fragmentation.
  
  

• Earthworms breakdown plant remains (dead plant matter) into smaller pieces. So, point 1 is correct.
  
  

• Jellyfish are carnivorous (or parasitic), feeding on planktonic organisms, crustaceans, small fish, fish eggs, larvae, and other jellyfish. So, point 2 is not correct.
  
  
• Millipedes are slow-moving detritivores. They eat decaying leaves and other dead plant matter. Some eat fungi or drink plant fluids. So, point 3 is correct.
  
  
• Seahorses feed on small crustaceans floating in the water and crawling on the bottom of the sea. They ambush prey that floats within striking range. So, point 4 is not
  correct.
  
  
• Woodlice are usually nocturnal and are fed mostly on dead plant matter. So, point 5 is correct.
  

Therefore, option (3) is the correct answer.

Subject: Environment | Ecology