CNN talks with researcher about bug breathing
(CNN) -- CNN Science Correspondent Ann Kellan interviewed Mark Westneat, associate curator of zoology at The Field Museum in Chicago.
QUESTION: Could I say this is the first time scientists have seen in detail, how bugs breath?
WESTNEAT: Yes, this is the first time anyone has generated a high-resolution x-ray of insect breathing. People have gotten fuzzy images of abdominal pumping with infrared, but this is much higher resolution. There are two really cool aspects of this project.
• This research uses a new technique for obtaining x-ray videos of living small animals at micron resolution (one millionth of a meter). This approach uses the synchrotron accelerator x-ray beam at Argonne National Laboratory to generate real-time phase-enhanced x-ray images that may revolutionize the study of biomechanics in small animals. This is an integration of high-energy physics with biology that yielded an amazing new find.
• The new find is that insects breathe with an astonishingly high volume change. Previously we all thought that most insect breathing tubes were fairly stiff, but they are anything but stiff. They collapse and reinflate by flattening, and their air exchange is about 50%, similar to a person doing mild exercise. This has major implications for how insects run, fly, survive, behave, and how they have evolved.
QUESTION: Do they basically breath through their outer skin with the help from the muscles?
WESTNEAT: Well not quite. Their "skin" is a waxy shell-like cuticle that is impervious to air and water penetration (some larvae are permeable though). A complex system of interconnected tubes (tracheael system) branches out inside the animal, and is connected to the outside air through portholes in the cuticle called spiracles. The spiracles can open and close. When the spiracle is open, the tracheae can be compressed to exhale a puff of used gas and inhale fresh air. The tracheae branch and get smaller and smaller, and eventually deliver oxygen to cells like muscle, brain, etc.