How does the blue whale not swallow liters of water when it catches its food?

Blue whales don't swallow liters of water when they catch their food because they use a special feeding technique called baleen filtering. Here's how it works:

1. Opening wide: Blue whales open their massive mouths wide, engulfing a large volume of water containing krill or other small prey.

2. Baleen plates: Instead of teeth, blue whales have baleen plates made of keratin (the same material as human fingernails). These plates hang down from their upper jaw, creating a sieve-like structure.

3. Closing the mouth: Once the mouth is full, the whale closes it and pushes the water out through the baleen plates.

4. Trapped prey: The baleen plates act as a filter, trapping the krill or other small prey while the water is forced out.

5. Swallowing: The whale then swallows the concentrated food trapped in the baleen plates.

This process allows blue whales to filter huge quantities of water, capturing their food without swallowing large amounts of water. It's a remarkably efficient feeding method that allows them to consume enormous amounts of krill, their primary food source.