The color intensity of the royal gramma Gramma loreto tends to fade with declining water quality,
making it a “canary in a coal mine” that can alert the aquarist to potential tank problems.
bath (use water that is dechloraminated and
of the same temperature and pH as the water
in your tank) in a small container to help
rid its body of as many attached parasites
as possible. Most marine fish will tolerate
spending a short period in fresh water, but
many external parasites cannot. The fresh
water flows into the tissues of the parasites
(where the salt concentration is higher than
that of the surrounding water), causing them
to burst or to swell up and detach from the
host fish.
to remove them, dip them in fresh water,
and transfer them to the hospital tank for
treatment as well.
Once the parasites reach the free-swimming
stage, they must find a fish host within a
certain number of days or they will die.
Therefore, removing all of the fish from your
display tank for at least 4 weeks (which
encompasses the entire lifecycle of both
Cryptocaryon and Amyloodinium) is the
best way to prevent re-infection.
While dipping the fish in fresh water,
monitor it very closely and return it to salt
water immediately if it shows signs of severe
distress. After the freshwater dip, you can
place the fish in the hospital tank where it
can be monitored—as well as medicated—if
it continues to show symptoms.
Q
Defective
Gramma?
Cryptocaryon and Amyloodinium have
similarly complex lifecycles, which include
actively feeding on a fish, dropping to the
substrate and forming a cyst, reproducing
inside the cyst, and then hatching out in
much greater numbers as free-swimming
parasites to find a fish host. If one of these
parasites is your problem, then your other
fish are at risk of becoming infected. If
you manage to catch the problem early
enough—i.e., before the parasites have a
chance to form cysts and detach from your
rabbitfish, you may dodge the proverbial
bullet. If you don’t catch it early enough and
your other fish become infected, you’ll need
My royal gramma seems to
prefer to hang upside-down
avorite cave. When it comes out
to grab food floating by, it swims normally,
but whenever it is in its hiding place, it goes
right back to that strange position. Is this
behavior normal, or do I have a defective
specimen?
inside its f
Jon Roepke
Houston, Texas
A
I can assure you that your royal
gramma Gramma loreto isn’t
defective. In fact, this behavior,
though odd and amusing to
observer, is perfectly normal. This
species tends to orient its belly toward a hard
substrate, and that can translate into the
sides or ceiling of a cave or the underside of
an overhanging ledge. Many hobbyists find
