It has been claimed that the paramecium is the most sophisticated and complex protozoan. That,of course, is utter
nonsense! There are protozoans that are more sphisticated and complex than
the paramecium. Some, for example have multiple nuclei and others, such as the vorticella, can assume 2 or more body forms. It may
be true that the paramecium is the most spophisticated protozoan mentioned in my highschool biology textbook,
but the amoeba, euglena, paramecium and diatoms mentioned in that book are just a tiny fraction of the protozoans known to science.
Having said that, the paramecium is an interesting organism. Like the typical protozoan, the paramecium can reproduce by binary
fission, AKA cell division, thus producing genetically identical "clones", but, like several other groups, the paramecium can also
reproduce by conjugation. In conjugation two
paramecia form a connection and each receives a copy of the other's DNA, reulting in double the normal number of choromosomes.
Then they go their seperate ways and each one splits in two 3 times, eliminating some of the extra chromosomes until finally there
are 16 individuals with the normal number of chromosomes, but each with a different combination of the DNA of the two original
What is really intersting is that not just any two paramecia can do this. Paramecia have two "genders" known as "plus" and "minus",
the difference being a chemical "scent" similar to a pherenome. Only a plus and a minus can conjugate. Since the result of binary
fission will always be either two plusses or two minuses, conjugating paramecia will never be clones of each other.
Here is a video of several small paramecium along with some colpoda and
bacteria at 400X.
These videos were from my own hay infusion based on samples collected in Northern California, 95841.
I hope you enjoy my microscopic videos of