Tickle Your Taste Buds
To what lengths would you go to get a fresh meal? It is commonly know that anteaters use a sticky substance on their tongues to trap insects like ants and termites, but did you know that some lizards have a similar style of eating? Horned lizards trap their prey in large gobs of mucus before actually swallowing them.
This may seem like a bizarre trait but it is actually quite practical. The Horned Lizard's primary food source is harvester ants, which have both a poisonous sting and terrible bite. How they have managed to consume these ants without injury was unknown until just recently. Biologist Kurt Schwenk observed the horned lizards eating hundreds of ants at a time, using their darting tongue to sweep them up and swallow them whole, which was not the usual behavior of a lizard. Biologist Wade Sherbrooke was also studying these lizards at the time, performing autopsies of fresh, road kill specimens. These two biologists teamed up to continue their studies and find a reason for the lizard's bizarre eating behavior. As they proceeded with their investigation, they found tiny, finger-like protuberances at the back of the throat with many mucus producing cells (this structure had not been found in any of the other lizard species).
Schwek and Sherbrooke's findings led them to conclude that the horned lizards use these mucus-secreting protuberances to coat the ants so that they are incapacitated, allowing the lizard to swallow them whole. Essentially, the lizard quickly grabs an ant with a flick of it's tongue, forces it to the back of the throat where it is covered in mucus, and then swallows it whole without any problems. Scientists say that the next step will be to understand the efficiency and quickness of this feeding behavior.
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-Jen Kodela (3)
posted by PWH @ 10:11 PM
6 comments
6 Comments:
Thats an amazing discovery....I wonder how that feature evolved in that species of lizard. Most lizard eat insects...but I wonder if other types of lizards have evolved something similar.... which hasn't been discovered yet.
-Joanne Philippeaux
Where were these horned lizards from that they studied? What is in the mucus that they secrete?
SUSAN DUONG
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This is quite interesting. Have these cilia-like structures found in these horned lizards evolved from the same kind of finger-like protuberances found in the nasal passages of humans and other mammals? Was this something that evolved to be moved to the back of their throats?
Ahmed Sandakli
That's really neat how they found those protuberances! Why do you think only one lizard has evolved like that? Do you think it could be because they were that desperate for food? That would be my guess. I wonder if any other animal has these that we aren't aware of...
Alyson Paige
UPDATE
First, I realize I incorrectly placed the link to the article. Here is the actual one- http://sciencenow.sciencemag.org/cgi/content/full/2008/929/2 .
Addressing Joanne-
The article spoke about this habit not being common between other species of lizards. I think a practical possibility for why this feature evolved in the horned lizards is to be able to more effectively consume their food source. The mucus prevents them from being harmed by the vicious ants.
Addressing Susan-
Horned lizards live in several different places but this article was addressing those studied from the American West. I was unable to find what exactly was in the mucus, but it is essentially an incredibly sticky substance that can effectively ball up their prey.
Addressing Ahmed-
The protuberances are actually glands that extend from the pharynx. There is not conclusive evidence on how exactly these structures evolved. There are however other mucus secreting surfaces along their esophogeal folds, which could have evolved into protuberances over time.
Addressing Alyson-
The horned lizard preys on particularly dangerous insects, like the harvester ant, which many other lizards choose not to eat. These insects are not very nutritious and are also rather indegestible and bitter. The horned lizard is also unique because it does not chew its food at all. I think that all of these things contribute to the evolution of their mucus secreting protuberances.
-Jen Kodela
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