Evening star., 1934-07-30
THIS AND THAT
BY CHARLES 4. TRAcTWELE.

The water IS then drained OF and
the pool flushed with clean water. care
being taken TO thoroughly scrub the
walls. After 1t Is filled It may be
stocked with fresh plants and the old
fishes, but not until these have been
kept under observation for several
days to see II any new parasites are
forming.
The work Of pulling away the Cope
pods Is not al all nice. The thread
parasite is, indeed. a loathsome thing
leaving the fingers of the operator
smelling badly.
One local pool enthusiast pulled but
two Copepods from fish. after which
he washed his hands thoroughly with
strong soap. but his hands smelled so
badly. he said. that he WAS forced to
eat mis- dinner in another room, the
family protesting his presence.
II will be realized. therefore. that
the presence OF this dread creature in
the lily pool has many disadvantages.
The gentleman above mentioned
found these Copepods on his fishes a
few months after accepting the gift
OF some water lilies from a friend.
Previously he had purchased all his
fishes and lilies from a nearby gold
fish farm which had suffered at one
time from this parasite. and has been
ever since on guard against It, to the
extent of microscopic examinations,
etc.
The local water gardener had nc
trouble with fishes or plants that year
but last Winter the unusual cold
froze the roots of his lilies.
When a friend offered him some,
therefore, he accepted the offer gladly.
Then came the Copepods. While
he has no sure way Of knowing that
they entered on the new lily roots. he
believes that they did, and he is
probably right.
1t is possible, however. that IL he
bought even one new fish this Spring,
the parasites might have been on it,
in immature form, scarcely 10 be
noticed except by one who might have
been looking for that very thing.
The habit of this parasite of an
choring itself in the flesh of the poor
fish has led some to call it the anchor
worm," although 1t is not a true
worm, but belongs to a group of crea-
lures known as Lernean parasites.
The eggs are laid at the outer end
of the threadlike body. in vessels
known as tabs" and finally fall TO
the bottom. where they hatch out.
The young are free-swimming, and
seek host. To date no chemical that
has been tried has been strong enough
to kill the Copepod without killing the
fish, that is why the latter must be
removed before the pool is treated as
above outlined.
Latest researches indicate that
these disgusting creatures breed most
freely in alkaline water, which is, of
course, the very sort goldfish enjoy
the most.
1t is, therefore, felt that future ex-
periments must be along the line of
slightly acidifying the water, in an
effort to kill the parasites and pre-
vent new ones from Matching out,
without at the same time injuring the
fish. The old standard goldfish
remedy, a strong salt solution, say of
two teaspoonfuls of ordinary salt TO
the gallon of water, leaves the Cope
pod feeling fine.
Experts agree that no fish can stand
more than three of the mature para
sites. If he accumulates more, his
death is sure. 1t may be seen, there
fore, that the task of pulling them
out will not be so great, after all, and
since it is the only method of control
evolved to date, it must be tried by
the pool owner who wishes to save
his attacked fish. Any fish found
dead in the pool should be examined
for Copepods as routine.