Whale of a Mystery: Why Those Ribs?

May 14, 2008 -- While dissecting a pygmy right whale at The Museum of New Zealand Te Papa, scientists there discovered that the creature possessed ribs unlike those of any other whale. Only one other animal is known to have a similar set: the anteater.

The ribs suggest pygmy right whales are stiffer in the water than previously thought, moving more like fast torpedoes than undulating fish.

"The international research team that just completed the dissection determined that the whale's ribs were flattened and overlapping," Te Papa museum spokesperson Jane Keig told Discovery News.

Sentiel Rommel, a lecturer in oceanography from the University of Maine, participated in the project.

He explained that a small amount of flesh between each of the ribs allows the otherwise packed ribcage "to move as the whale breathes and also accommodates changes in volume that occur as the air is compressed by water pressure when the whale dives through deep water."

Rommel added that the ribs' wide, flattened structure has only been observed before in certain types of anteaters. Studies on anteater ribs have indicated that the rib arrangement helps to stiffen their bodies as well.

"So, possibly, a stiffer body has advantages in the way (pygmy right whales) swim, but this is purely speculative at the moment," he said.