According to S.J Clark, T.J Dawson, and I.D Hume
research about koala digestion system, this small marsupial animal is likely to
have difficulty processing sufficient quantities of their poor-quality food,
Eucalyptus leaf, to meet their metabolic needs. Eucalyptus leaf is rich in fiber
and have large amounts of lignin, which is indigestible by lightweight animal
such as the koala. Those researcher found that there are three major factors
that allows this marsupial to exploit its roughage-laden diet (Journal of
comparative physiology B, vol. 153, p.181) and that is why koala’s digestion
system is special.
First,
the koala has a discerning digestive system which allow them to regulate the
passage of food through their guts. The alimentary canal retains solutes and
smaller digestible particles in caecum and colon, this is probably a
space-saving exercise; it has effect of increasing the rate at which raw
material can be fed into the system.
Second,
the koala has a low overall requirement for their metabolic energy, compared to
other marsupial of similar size such as, the three-toed sloth.
Third, and the last factor is eucalyptus leaf has hidden
qualities. Despite the preponderance of lignin and other indigestible matters,
there are amount of carbohydrates such as, sugar and starch which will satisfy
the bulk of the koala’s energy needs. Also, constituents of the eucalyptus cell
wall such as, cellulose are less important. However, it is digested with the
help of microbes in the hind gut.
As can be seen, the koala digestion system might develop
because of evolution. This evolutionary in digestion system probably happen
because koala is a slow-moving marsupial and cannot reach another tree so, they
have no choice but eat eucalyptus leaf. Just like Darwin says, the best adapter
animals are the one who can survive and that is what might happen to koala,
they adapt to survive.
(Reza)
here are pics of cute koala and epic koala...
