Throat grooves are deep folds of skin located on the ventral (underside) of a baleen whale's throat. These grooves are highly expandable and play a crucial role in their feeding process.
Here's how it works:
1. Expansion: When a baleen whale encounters a school of krill or other small prey, it opens its mouth wide, expanding its throat grooves to create a massive cavity.
2. Water Inflow: The whale takes in a large volume of water along with its prey.
3. Contraction: The whale then closes its mouth and contracts its throat muscles, forcing the water out through the baleen plates in its mouth.
4. Filtering: The baleen plates, which act like giant combs, trap the krill or other prey, while the water is expelled.
The throat grooves are essential for:
* Increasing the volume of water the whale can take in - This is important for maximizing their food intake.
* Creating a vacuum-like suction - The expansion and contraction of the throat grooves help create a suction that draws water and prey into the whale's mouth.
So, while they may look like pleats, these grooves are a crucial part of the baleen whale's feeding apparatus.