~~~ The
Big One ~~~
A single-cell organism has been found that is large enough to trip over!
This little? critter was discovered within a Red Sea surgeonfish,
[the best surgeonfish -
what is that, anyway? - I could do..] and was
first thought to be a protozoan (another kind of little critter - but
unlike bacteria, pretty big - big enough to see without a microscope).
Remember, we can't see anything that is less than about 200 micrometers in
size (200-millionths of a meter - which would appear as an incredibly tiny
speck, but could indeed be seen). Bacteria range from about 0.2
micrometer to 1.5 micrometers. (this "sizing" in fact, is one
means of
classifying something as a bacterium, and not a horse). Take a gander
at some relative sizes of living cells by accessing Jim Sullivan's Page
at: Cells Alive!
This bug we are presently discussing, Epulopiscium fishelsoni is
almost 250 micrometers! However, Norman Pace, now at the University of
California, Berkeley, has been looking at the genes of this bug and is
using PCR (polymerase chain-reaction) to amplify DNA sequences known to be
associated only with bacteria. From these studies, Pace has produced
evidence that this bug is actually a bacterium! If the data hold up, and
they appear to be pretty darn strong, then this bug will be the largest
bacterium ever discovered - several hundred-times larger than the
largest known bacterial cell. You could spot the darn thing on your
tablecloth! This information is causing quite a stir among taxonomic
types, and is causing everyone who works on bacterial physiology,
bacterial genetics, and, who classify bacteria, to re-evaluate things -
especially the rules of classification. Ah, science, the more we learn,
the more we need to learn. Keeps you hoppin'.
Take a look at a related article which discusses the fact that bacteria
of this species (Epulopiscium) have babies! Please see:
Bacteria Have Babies - No Kidding!
Book: Don't Touch That Doorknob!