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Dear Anonymous,
Sponges are very simple animals whose cells are not organized into discrete
tissues. They are capable of incredible regeneration. The classic
experiment to demonstrate this property is to force a sponge through a fine
mesh to separate the cells. After a while, the cells re-aggregate by type
and reform the sponge's body.
I've never done this experiment myself, but here's how I'd try to do it.
I'd take a live sponge (I'd use a marine species, since I leave on the
coast, but I suppose it would work with freshwater sponges, too) and push it
through a mesh of about 50-100 microns (a micron is one-thousandth of a
millimeter). Where do you get the mesh? Your teacher may have some fabric
called nitex that comes in many mesh sizes and is used to make nets and
sieves. Or you can use a few layers of ordinary cheesecloth that you can
buy at a fabric store. Why 50-100 microns? It's just a guess, really. The
idea is to separate the sponge into its individual cells or very small
clumps of cells, and my gut feeling is that 50-100 microns would suffice for
our purposes. You should end up with a cloudy slurry of small sponge bits
in seawater.
Keep the seawater at the temperature that is normal for the sponge (don't
let it warm up too much) and leave the dish for a while. I don't know how
long the re-aggregation process takes - an hour or two? Anyway, after
waiting for a bit, check to see if the sponge bits are a little larger.
They should be, if the cells are re-aggregating. The clumps should grow and
the seawater should get progressively clearer as the process continues.
I don't know if you should expect to get one sponge body, or several smaller
ones. I'd be interested in finding out, so if you do the experiment, please
let us Mad Scientists know what happens.
To the coast! |
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