Date: 30 Jan 1998
From: David Bloch <ebloch@alphas.curtin.edu.au>
To: AQUA-L@killick.ifmt.nf.ca
QUESTION:
On a recent post regarding Tubifex worms I saw a mention of whirling disease. Can someone give me some information about it?
David L. Bloch
ebloch@alpha2.curtin.edu.au
http://student.curtin.edu.au/~ebloch/reeftank/
Aquarist
Underwater World, Perth Western Australia
Aquatic Technologies - Consultant, Design, Construction
and Maintenance of freshwater and marine aquatic systems
mobile: 0412 079886, tel/fax: +61 8 93752438
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COMMENTS 1:
This is a well known fish parasite, that affects fingerlings.
Fariano Lucio, lucio@www.lrcser.it
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COMMENTS 2:
Whirling disease is a parasitic infection of trout or salmon caused by the protozoan Myxobolus cerebralis. Signs of the disease are the result of the parasite feeding on the cartilage of young host fish. A common sign of the disease is rapid, tail-chasing behavior when fish are frightened or trying to feed. The course of the disease ranges from sub-clinical infections to acute disease with mortalities of fry and fingerlings.
A good recent reference on this parasite problem is the proceedings of the Symposium on Pathogens and Diseases of Fish in Aquatic Ecosystems: Implications in Fisheries Management, June 3-4, 1997.
For info or a copy of this publication, contact Dr. Scott LaPatra at: scottl@clearsprings.com
Dave Conley, MSc
Aquaculture / Fisheries Biologist
D.C. Conley & Associates
Comox, BC, Canada
Voice/Fax: 250 339 9892
e-mail: corcon1@mars.ark.com
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COMMENTS 3:
"Whirling disease" is caused by a microscopic parasite called
Myxobolus cerebralis. It is an internal parasite, and when infections are severe, cause the infected fish to "whirl" when stressed. This parasite has been known to cause extensive mortalities in the trout industry.
CAUTION: I have often seen the term "whirling disease" used to
inaccurately describe certain bacterial infections. Sometimes heavy
organically loaded aquaculture water can cause bacterial infections to
build up behind the eyes forming a type of exophthalmia. Under severe infections this can cause pressure upon the nervous system causing the fish to whirl. In fact there are many afflictions which can cause fish to "whirl", with only one of them being "whirling disease".
Michael H. Schwarz
Aquaculture Specialist
Virginia Seafood Research and Extension Center
Virginia Tech
PO Box 369
Hampton, VA 23666
757-727-4861 Fax: 757-727-4871
mschwarz@vt.edu