Aquatics

Question 1

Agent for Ich/White Spot Disease

Answer 1

Ichthyophthirius multifiliis –> a large, motile ciliate with a horseshoe shaped macronucleus

Question 2

Clinical signs of Ich

Answer 2

Flashing –> fish quickly rub or scratch themselves on the pond bottom or objects
Small white spots on skin and gills

Question 3

Ich treatment

Answer 3

Formalin and hypersensitivity

Ich lifecycle speeds up with warmer temp so increase treatment frequency as temp increases

Question 4

Describe Marine White Spot Disease

Answer 4

Caused by parasite Cryptocaryon irritans which is the saltwater version of Ich

Treatment: copper sulfate pentahydrate; less commonly use hyposalination, chloroquine, formalin

Question 5

Describe agent of Whirling Disease

Answer 5

The parasite Myxobolus cerebralis

Question 6

Describe Whirling Disease

Answer 6

Affects juvenile aged salmon –> skeletal deformation and neurological clinical signs where they whirl forward in corkscrew manner

Mortality can be up to 90%

No effective treatment –> prevent with biosecurity and sanitation

Question 7

Dactylogyrids

Answer 7

Microscopic flatworms with distinctive eye spots affecting gills of fish

Clinical signs: lethargy, clamped fins, poor appetite, flashing, gulping at surface for air, scale loss; gills swollen and pale; death with heavy infestation

Treatment: praziquantel (ornamental and aquarium fish); formalin or hydrogen peroxide for aquaculture settings

Question 8

Gyrodactylids

Answer 8

Microscopic flatworms found on fish skin and fins with fully developed embryos visible to naked eye

Clinical signs: lethargy, clamped fins, poor appetite, flashing, gulping at surface for air, scale loss; gills swollen and pale; death with heavy infestation

Gyrodactylus salaris is OIE reportable pathogen

Treatment easier than Dactylogyrids –> no egg stage is treatment resistant

Question 9

Describe Fish Lice

Answer 9

Argulus spp –> crustacean parasites of fish found on skin, gills, mouth

Treatment at all life stages: diflubenzuron, emamectin, potassium permanganate; can manually remove adults

Usually from new fish introduction so have proper biosecurity

Question 10

Describe Anchor Worms

Answer 10

Lernaea spp –> freshwater crustacean, copepod parasites found on skin, gills, fins, mouth of fish

Clinical signs: gill damage and respiratory distress; inflammation leading to secondary bacterial and mold infections

Can remove individual organisms manually

Treatment: salt (food fish); salt, trichlorfon, potassium permangenate or diflubenzuron