Herbivery in Siren lacertina

[edward]

In the past, it was thought that the plant matter consumed by greater sirens was an artifact of thier feeding behavior but an examination of thier digestive tract has documented that there is fermentive digestion (like in other herbiverous animals) occuring with the ingested plant matter. This indicates that Siren lacertina is not an obligate carnivore and requires a reevaluation of the diet fed to them as they probably require some level of plant matter.

For a full review see
Pryor, Gregory S.; German, Donovan P.; Bjorndal, Karen A.; 2006; Gastrointestional fermentation in greater sirens (Siren lacertina); Journal of Herpetology 40(1):112-117

Ed

 

[nate]

Wow! Pretty amazing find. Still though, doesn't seem to that they are "grazing" and the intake is facultative.

 

[edward]

Hi Nate,

The amount of plant material ingested has to be considerable to maintain a level of microbial growth that will ferment the material.
It is a very interesting article. There was a lot of good articles in that volume. I will post some more of the citations after IAD when I have a little more time.

I wonder if they have commensual nematodes along the lines of herbiverous reptiles that help facilitate the digestion.

Ed

 

[nate]

Right, I know they are ingesting a bunch, but incidental. I guess what I'm trying to say is, we're not going to see a hungry Siren ever intentionally start munching on hornwort anytime soon, for instance.

Was there any mention of what this means for intermedia or Pseudobranchus? So weird...

 

[jennifer]

That's quite a shocker.

 

[TJ]

Did anyone else wonder why they assumed it was cellulose being fermented? Chitin fermentation has been documented in several other arthropod and fungus-eating species and chitin fermentation also results in the fatty acid chains they documented. It would seem to me the more likely conclusion given the observed dietary preferences, and the seemingly off-base numbers they got in comparison to cellulose fermenting herbivores. Did I miss something in the article?

-Tim