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Name _____________
Exam II
Fish 424 (Fish Health)
April 16th, 2003
Please read each question carefully and provide complete answers. Good luck! (100
pts total)
1. (10 pts) Scott Williams discussed the use of family selection in commercial
aquaculture. What two diseases has Clear Springs Foods been attempting to
select resistant rainbow trout strains for. Explain what the key feature is that
eliminates the risk of selecting fish that could be potential carriers of an infection?
2. Match the items in the following list to the appropriate fish disease. Place the
letter associated with the pathogen or symptom in the blank corresponding to the
disease in which it causes. (2 pts each)
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
Aeromonas salmonicida
Yersinia ruckeri
Renibacterium salmoninarum
Rhabdovirus
Necrosis of pancreatic acinar cells
Flavobacterium branchiophilum
virus targets epithelial tissues
Flavobacterium psychrophilum
“haystack” formation
A. hydrophila
Zoonotic
3. (2 pts)
a.
b.
c.
d.
e.
___ Coldwater disease (CWD)
___ Columnaris
___ Bacterial gill disease
___ Furunculosis
___ Bacterial kidney disease (BKD)
___ Motile Aeromonas septicemia
___ WSIV
___ (IPN)
___ Mycobacteriosis
___ Enteric redmouth (ERM)
___ Infectious hematopoietic necrosis (IHN)
Which clinical symptom is caused by a deficiency in the vitamin niacin?
cataracts
broken back syndrome
brown blood disease
sunburn
None of the above
4. (2 pts) Which fish disease was the first commercial aquaculture vaccine/bacterin
developed against?
a. Enteric Redmouth
b. Furunculosis
c. Coldwater disease
d. Infectious hematopoietic necrosis
e. Bacterial Kidney disease
5. (2 pts) ____________ poisoning is caused by feeding moldy feed and results in
acute mortalities and large tumors forming in the livers of affected fish.
6. (2 pts) (True or False) An attenuated virus can often be produced by multiple
passages in tissue culture.
7. (2 pts) Name 2 concerns over developing attenuated viral vaccines.
8. (2 pts) The number one disease problem in Catfish aquaculture is causes by what
pathogen?
9. (2 pts) Some fish pathogens are considered zoonotic. Name one, and describe
how a person may become infected with it.
10. (2 pts) What do many bacteria produce that can cause direct damage to host cells
and tissues?
11. (2 pts) What parasite products are considered toxic and can cause host cell and
tissue damage?
12. (5 pts) Ben LaFrentz discussed the immune response of fish to Flavobacterium
psychrophilum. Explain how passive immunization was used to determine the
importance of antibodies in protection of fish from coldwater disease.
13. (8 pts) What occurs during the replication process of IHNV that helps it partially
evade the host’s immune system? During this process, what component (antigen)
is capable of being recognized by the host and is important for stimulating a
protective immune response?
14. (2 pts) If a diet were deficient in vitamin C, what clinical symptoms would you
expect to see in fish.
15. (4 pts) Lymphocytes are made up of 2 major cell types. 1) Name these 2 cell
types, and 2) name the organs that each cell type is derived from.
16. (2 pts) During the immune response, cells work together to produce an immune
response to a pathogen/antigen. What important molecules are produced and
found in the serum as a result?
a. Cytokines/lymphokines
b. Antibodies/Immunoglobulins
c. Complement proteins
d. All of the above
e. None of the above
17. (3 pts) Define “CPE” and explain why is it important for disease diagnostics?
18. (5 pts) Draw the life cycle for Myxobolus cerebralis.
19. (3 pts) Why are brown trout less susceptible to whirling disease than many other
salmonids?
20. (3 pts) Myxobolus cerebralis spores can survive outside the host for up to 30
years. What can anglers do to help limit the spread of these spores between water
sources?
21. (15 pts) Fish hatcheries rearing chinook salmon in the Pacific Northwest have
implemented 3 major steps to reduce the incidence and impact of Bacterial
Kidney disease. List these 3 things and explain what the significance of each is.
Extra credit
(2 pt) What is a virion?
(2 pts) Describe how a granuloma is formed and name a disease where this symptom
is common.