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Home: Articles
Research on Shell Disease
Since January this year I have been spending a lot of time
researching the incidence of black, brown, rust coloured
stains and small holes in exoskeletons. Some were negligible
and just part of the colouration of the hermit crabs, while
others became fatal pre and post-moult.
I have been talking with a number of fish experts and searching
for common symptoms and I think I have finally found what
we are facing.
It is known as Shell disease, Black Spot, Brown Spot, or
Rust Disease/Spot.
The very close relative of land hermit crabs are Lobsters/Crayfish,
and Shell Disease is very well known in Lobster/Cray circles,
with the discolorations and melanization (discolouring)
and raised 'pock' type markings turning people off eating
the crayfish meat, even when the fungus is killed on cooking
the seafood.
According to many Lobster research bodies it is very contagious
and as Jenn pointed out in her Journal/Literature Review
a few months ago, many fungi actually feed on the chitin
of insects/crustaceans, and what this means is that the
fungus is able to feed directly from the chitin of our land
hermit crabs despite the fact there are no other food sources
or sources of bacteria.
Some treatments are being used with Lobsters/fish and the
like but as yet there is no certain cure. Many advocate
giving a salt water dip and prevention using probiotic type
foods such as Spirulina, as well as the addition of Vitamin
C to the diet; and a few have said that antibiotics may
help stave off worsening of the condition.
The next email will outline a few of the treatments used
in Aquaculture/Aquatic circles but before we progress to
treatment, it is important that we learn more about what
it is. One thing of note is that many Lobsters/Shrimp/Prawns
that are severely affected do not survive the next moult
due to insufficient function of the gills. Perhaps that
is why most hermit crabs seem rather unaffected until the
pre or post-moulting condition.
Hopefully this will be one of the few mysteries of land
hermit crab care that we can join together to research,
and fight with everything we have learned.
Vanessa
============= Shell Disease ============
The disease is caused by the chitinolytic bacteria that
eats chitin, a cellulose-like substance in lobster shells.
It's been around for years, but now appears to be spreading
more quickly than ever, Estrella said. ''It's a different
strain of bacteria, more virulent and fast-moving,'' he
said.
http://www.fishfacts.com/sfdpriv/news1/20010726LSDN.html
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