UPSC Prelims 2024 Question:

Consider the following

1. Butterflies 
2. Fish
3. Frogs
   
   

How many of the above have poisonous species among them?

Explanation:

• Butterflies often eat and store toxic chemicals while feeding on their host plant as caterpillars. Many butterflies use poisons to survive and advertise their noxiousness with specific “leave me alone” colours. Heliconian butterflies of the Americas, also called longwings, deploy cyanide to protect their eggs from predators however, these insects have evolved to tolerate the plant's defensive chemicals and many have become often dependent on them. So, point 1 is correct.
  
  
• Pufferfish is the most poisonous fish. Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes.
  
  
• Stonefish have venomous spines along their dorsal fins. The venom can cause severe pain, swelling, tissue damage, and in some cases, death if not treated promptly. So, point 2 is correct.
  
  
• Many species of frog are known to be poisonous, such as the often colourful poison dart frogs. But although incredibly rare, there are species that are venomous too. There are currently only two species of frog known to be venomous: Bruno's casque-headed frog (Aparasphenodon brunoi) and Greening's frog (Corythomantis greeningi). Both are found in Brazil and produce skin secretions like other poisonous frogs - but these species have spiny bone protrusions that make their poison venom. So, point 3 is correct.
  
  

So, all three of the above have poisonous species among them. 

Therefore, option (3) is the correct answer.

Subject: Environment | Plant and Animal Anatomy