1. Toni Christopher

2. Before We Begin…Some Key Terms  Aquaculture: human cultivation of aquatic plants or animals in controlled environments  Fry: fish children  Fingerling: young or small fish  Hatchling: newly hatched fish  Brood stock: fish used for breeding only  Hatchery: pond set aside for hatching eggs  Fry Pond: pond in which fry are raised and cared for

3. What is CCVD?  Viral disease specific to Ictalurus Punctatus  Causes hemorrhaging and destroys blood forming tissue in the kidneys  Leads to kidney failure and death  Temperature sensitive disease  More of a problem in aquaculture than in wild  Why?

4. External Symptoms  Slowing of feeding activities  Erratic swimming, often spiral  Hyperactivity followed by lethargy  Gathering along sides of ponds hanging vertical and motionless  Swollen abdomen  Extension of anus  Bulging Eyes  Hemorrhages  Base of fins  Abdomen  Muscle Tissues  Gills occasionally  Liver and kidney  Pale gills

5. Internal Symptoms  Clear yellow to blood tinged fluid in body cavities  Digestive tract: yellow fluid and mucus, no food  Pale liver and kidneys  Dark spleen  Inflammatory cells overrun infected areas

6. Susceptibility  Varies among strains of catfish  Inbred strains: more so  Outbred strains: more vigor and increased resistance  Ictalurus furcatus: naturally resistant  Channel x blue hybrids: same as parent channel cat  Bullheads, Euro., Afric., and Asian: resistant  Pangasius sp.: unknown

7. An Important Note About CCVD  Temperature Reactive  At 4 °C, virus life: ≤ 28 days, mostly dormant  At 20 °C, symptoms dormant up to 10 days  At >25 °C, outbreaks typically occur,; virus life: 2 days  At 25 - 30 °C, symptoms seen 2-3 days after infection  Mortalities near 100% after a week  At >30 °C, greatest mortalities in smalls  Fish size and the amount of virus the fish are exposed to play a lesser role

8. Transmission  Fish to Fish  Direct contact with dying/infected fish  Virus crosses lining of gills and then intestines  Brood stock to young  Survivors may have dormant virus  Passed to young at or around spawning via semen and eggs

9. Treatment  No true effective treatments  Transmission can be limited by less feeding  Improving water quality and reducing temp. to < 19 °C reduce stress on fish and stops deaths  Control and prevention  Avoidance, containment, and stress reduction

10. Control and prevention  Avoidance  No feral fish  Quarantine new fish and survivors  Do not use survivors as brood stock  Containment  Sanitize and disinfect with bleach, dechlorinated water, and thorough air drying  No cross-contamination  Stress reduction  Optimal H 2 O quality; high dis. O 2 lvls.; avoid crowding, low circulation and flow; good nutrition

11. Resources and Images  http://aquanic.org/publicat/usda_rac/efs/srac/ 4702fs.pdf