Question 71 from UPSC CSE 2024 - Environm ent

Question

Consider the following:
1. Butterflies
2. Fish
3. Frogs
How many of the above have poisonous species among them?

Accepted Answer

Correct Option: C. All three

Strategy: Focus on whether any of the listed animal groups include known poisonous species. By recalling common knowledge and examples from each group—certain butterflies (like the African giant swallowtail), several fish (notably stonefish), and various frogs (such as poison dart frogs)—it's clear that all three have poisonous members. This direct recall affirms that the answer is all three.

Key Info: Butterflies: While butterflies are typically considered harmless, some species possess toxins. The African giant swallowtail (Papilio antimachus) is noted as the most poisonous butterfly and contains cardiac steroid toxins, which are highly toxic if ingested. Such toxins serve as a defense against predators.

Fish: Numerous fish species are venomous or poisonous. The reef stonefish (Synanceia) is considered the most venomous fish on earth; its dorsal spines inject potent venom, which can be fatal to humans. Other poisonous fish include pufferfish (which contain tetrodotoxin) and lionfish. Venomous fish deliver toxins actively (e.g., through stings), while poisonous fish harm upon consumption.

Frogs: Many frogs have toxic skin secretions to deter predators. Poison dart frogs (family Dendrobatidae) from Central and South America produce batrachotoxins, which are extremely potent. Additionally, some South American species such as Bruno's casque-headed frog (Aparasphenodon brunoi) and Greening's frog (Corythomantis greeningi) can both secrete and inject venom, making them unique among amphibians for possessing true venomous capability.

In summary, each animal group listed (butterflies, fish, frogs) comprises species with toxic or venomous adaptations for defense or predation.

Answer

Option A: Only one

Answer

Option B: Only two

Answer

Option D: None

Consider the following: Butterflies Fish Frogs How many of the above have poisonous species among them?

Consider the following:

Butterflies

Fish

Frogs
How many of the above have poisonous species among them?