What is krill and why is it important for whales?

In one line

The rule

Krill are small, shrimp-like crustaceans (animals with hard shells) found in oceans, and they are a main food source for many whales.

Let's understand it simply

Imagine you are eating poha for breakfast. It is small, easy to eat, and gives you energy. For whales, krill is like poha. Krill are tiny, pinkish sea animals, about the size of a large grain of rice. Even though each krill is small, there are billions of them swimming together in the ocean. Whales, especially the big blue whale, eat huge mouthfuls of water and filter out the krill to eat.

How it works

1. Krill swim in large groups called swarms in cold ocean waters.
2. Whales open their mouths wide and take in water full of krill.
3. They push the water out through special filters in their mouths, trapping the krill inside.
4. The whale then swallows the krill and gets energy.

The story behind it

Krill have been in the oceans for millions of years. Scientists started studying krill closely when they wanted to understand what blue whales eat. They found that without krill, whales could not survive. The word "krill" comes from a Norwegian word meaning "small fish."

Where you see it in real life

• In the Antarctic Ocean → Huge swarms of krill feed whales, seals, and penguins.
• In documentaries about blue whales → You see whales gulping water full of krill.
• In fish markets in some countries → Krill is sold as food for humans and pets.
• In the food chain → Krill eat tiny plants (phytoplankton), and whales eat krill.

Why it matters

• Krill are the main food for the biggest animals on Earth (blue whales).
• They are a key part of the ocean food chain.
• If krill numbers drop, many sea animals (whales, seals, fish, birds) will struggle to survive.
• Scientists study krill to check the health of the ocean.

Common mistakes

• Thinking krill are fish — they are actually crustaceans (like prawns or crabs).
• Believing whales eat only big fish — many whales eat only tiny krill.

Remember it

Krill are tiny, but they feed the giants of the sea.