Temperature’s Effect on Toad Speed

This little gem caught my eye on G+ thanks to Carl Zimmer.

Remember yesterday’s movie of the toad eating in slow motion? Now watch this one. It’s still a toad eating a cricket, but this time it’s filmed at two different temperatures. Keep two things in mind – first, the toad’s body temperature is the same as the air around it, and second, muscle works faster when it’s warm. That’s why it takes a lot longer for the toad to pull its tongue into its mouth and close its mouth at 17°C than at 24°C. But there’s no real difference in the time it takes to for the toad to fling its tongue out of its mouth. That’s because tongue extension is powered by elastic recoil. Slow muscle contractions pull elastic tissues inside the tongue tight while the toad’s mouth is still closed. When it opens, the tongue flies forward like an arrow from a bow. So whether it’s hot or cold, the toad’s always ready to go hunting. (see Deban and Lappin 2010:http://tinyurl.com/3ktz4ah)

Diane Kelly

Here’s the video:

In as little as twelve degrees Fahrenheit  difference, you can clearly see how much slower the muscles in the toad work.

Next time you’re trying to evade a predator in winter, be thankful you’re an endotherm. 😉

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One Response

  1. This is an interesting video. It reminds me of something I did with a class based on cricket chirps/15 s.

    It also relates to a story soon to be told on a new blog called As Many Exceptions as Rules (http://biologicalexceptions.blogspot.com). Body heat can be very interesting, including being linked to life exptectancy in humans.

    This blog is designed to give teachers and students interesting exceptions to biological rules in order to develop a forum in which core concepts can be discussed and reinforced.

    Recent stories have included three rules broken by a photosynthetic sea slug, rules of size limitation by diffusion being broken by mega-bacteria, and a current story on the sense organs and how our ears can produce sounds, and owls ears break the rule of body symmetry in order to develop an auditory field map

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