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Raising and Handling
California blackworms can be cultured and easily maintained in a small
aquarium or deep pan filled with 23 inches of springwater (or aged tap
water). At room temperature in the laboratory, populations double in about
34 weeks or less. Using a disposable plastic pipette, transfer a few
dozen, undamaged, healthy worms into the aquarium. Never attempt to handle
or transfer worms with forceps or hooks. They are easily injured by these
instruments.
Next, add enough strips of brown paper towel to just cover the bottom
of the container. The towel serves as a fibrous substrate of decomposing
material, both for the worms and for numerous microscopic organisms that
may cohabit the culture, such as bacteria, protozoans, rotifers, and
ostracods.
Add sinking fish-food pellets as the primary food source for this
simple aquatic ecosystem. Start by adding one or two pellets. After a few
days, add one or two more, but only if the others have been consumed. Do
not overfeed, since decomposition of uneaten food may contaminate the
aquarium and cause a mass die-off of worms. Worms are not harmed, however,
by irregular feeding or long periods of starvation.
Replace water lost to evaporation by adding springwater (or distilled
water).I recommend continuous, gentle aeration, and this becomes
increasingly important as biological decomposition of the paper occurs and
as the worm population increases.
As the paper towel disintegrates and waste residues accumulate, replace
the culture water regularly (about every two weeks) by slowly decanting it
down a drain. Be careful not to lose remaining paper and worms at the
bottom. After rinsing the paper and worms again with springwater, and
decanting, refill the aquarium to the original level and add new pieces of
towel. I suggest the occasional "harvesting" of surplus worms;
these can be used for classroom experiments, as live food for fish, or for
starting duplicate cultures. I strongly advise the maintenance of at least
one duplicate culture. If you follow these procedures, the worms reproduce
continuously by asexual reproduction (fragmentation), and cultures may be
sustained for years.
Handling the worms is easy, but you should follow certain important
precautions. Capture and handle the worms (or worm fragments) while they
are immersed in water. Using an eyedropper or plastic disposable pipette,
simply suck one or two up, along with a little water. Never pick up or
handle the worms with forceps, hooks, or metal probes because even a
slight injury by pinching or poking causes them to self-fragment (autotomize).
However, if blackworms do become "dismembered," you need not
discard the piecesjust save them for further experiments.
part c
©
Carolina Biological Supply Compagny, Article used by permission |
