Answer:

Whale Pleats

Throat pleats, or throat groves),allow the throat to expand a great deal (kind of like an accordion) This usually happens when the whale is catching masses of small fish with big gulps of water. This forms a pouch called a gular pouch.
First answer by Nirel. Last edit by Nirel. Contributor trust: 1934 [recommend contributor recommended]. Question popularity: 1 [recommend question].