A remarkable photo of Bryde's whale at the end of a lunge, showing the dramatic expansion of the accordion-like throat pouch. Photo courtesy of Doug Perrine.
For several years, I have been collaborating with a group of researchers from many different backgrounds to understand the biomechanics, functional, and evolutionary morphology of large baleen whales. Some of the work out of this team includes modeling efforts based on first principles in fluid dynamics and parachute physics; others have been much more hands-on (or elbows-deep), documenting their surprising anatomy; still others have used historical literature. All of these efforts ultimately are aimed at revealing how these ocean giants work, and how they evolved.
A. Wayne Vogl, professor in the Department of Cellular and Physiological Sciences (and editor of Gray's Anatomy for Students) at UBC, holds a microscope slide of stained rorqual nerve tissue below a blue whale skeleton mounted in UBC's Beaty Biodiversity Centre. Photo by Global News.
Our most recent work was published this week in Current Biology, as the cover article. Led by Wayne Vogl, along with researchers from Bob Shadwick's laboratory at the University of British Columbia, and Jeremy Goldbogen (Stanford University), we describe the unusual morphology of throat pouch nerves in rorqual whales. When this particular group of baleen whales feed, their entire mouth expands dramatically (in less than 10 seconds, for the largest species), requiring a complete reconfiguration of their basic mammalian jaw and throat anatomy. Previously, we described how the tissue mechanics of the accordion-like blubber around the throat permits this expansion (and return to its resting state); there are still big, unaswered questions about what happens to the tongue, and even how baleen works to strain captured prey, which remain very difficult to test.
Our Current Biology paper provides one more clue, mostly arising out of the serendipity of finding intact nerves during our anatomical fieldwork over several seasons in Iceland. Once we realized the enormous size and unusual gross morphology of the throat pouch nerves, we collected samples for histological section, which revealed their surprising organization, much like bungee-cords. This type of tissue organization allows them to stretch and recoil without injury, a property which is absolutely necessary to accomplish the dramatic engulfment that happens during a single lunge. Read more about the paper, including extensive media coverage, in the lab Publication section.