Lecture 7-8 Flashcards
Aquaculture
Controlled rearing of aquatic organisms
*fastest growing animal industry
What are issues vets are used for
Disease dx/control Legal drugs Health certification Food safety Reportable diseases
Who has the most production globally
China
What are the two basic types of production
Extensive vs intensive
Extensive production
Focuses on fishery management rather than aquaculture management
Low biomass:volume ratio
Minimal management required (no feed or aeration)
Intensive production
Managment is more like traditional farm management
Problems include crowding, water quality, nutrition, infectious dz
Feeding, water quality management, and aeration is required
Extensive production advantages
Little to no investment in equipment and feed
Fish can be trapped
Minimal water quality problems
Natural food is available in the pond
Used as source of protein from community managed ponds in region
Example of extensive prodution
Livebearers in Fl (guppies, swordtails, mollies, platies)
*due to lack of selective breeding many of these farms now do intensive production
Intensive production advantages
If indoors, more control and less predation
Massive increase in production
Intensive production disadvantages
Increased risk of dz
System failure results in catastrophic loss
High start up and operating costs
Complete diet required
Example of intensive production
Egg layer production- cobia fry, tilapia, angelfish in Fl
What are the types of production systems used in US
Earthen ponds (channel catfish, hybrid striped bass, shrimp) Raceways (rainbow trout) Cages or net pens (salmon) Re circulating tank systems (tilapia) Underwater lease (clams)
Advantages of pond production
Free or cheap water
Filtration and pump not required
Natural food available
Disadvantages of pond production
Minimal control of environment
Predation can be huge (birds, raccoons, gators, otters)
Difficult to maintain inventory
“Off flavor” hard to control and now fish cannot be marketed for consumption (caused by some algal blooms; not safety issue just quality control)
What is limiting factor for ponds
Dissolved oxygen
Advantages of raceway
Often use free water from river or other source
Use high flows instead of investment in filtration system
Inexpensive if not needing to continuously pump water
Disadvantages of raceway
Poor control of water source
Introduce disease and contaminants if using surface water
Concerns with effluent
Crowding facilitates rapid spread of disease
Treatments can be difficult because large volume of water used.
Cage culture advantages
Tidal flush provides free water
Risk of contamination or disease from local water
Easy to harvest
Disadvantages of cage culture
Controversial- aesthetics, environment Exposure to wild fish so potential dz introduction Susceptible to storm damage Predation Concern for damage to local environment Very crowded so dz spread Difficult to treat
Advantages of re circulating system
Complete control of environment
Elimination of predators
Very efficient grow out for suitable species
Treatment easier and less expensive than other systems
Disadvantages of re circulating systems
Very high capital investment High risk- power failure results in huge loss Intensive management requirements Expensive to operate and maintain Biosecurity is critical
Channel catfish
Most important aquaculture industry in US
Not a big business in FL but big in MS strategy
Very hardy, spawn easily in container, produce large egg mass to easily relocate to hatchery
Health concerns for catfish
Water quality (low dissolved oxygen, off flavor, ammonia/nitrite)
Infectious dz
Tilapia
Real Chicken of the sea
Very hardy and tolerant of poor conditions
Carp and koi
Same fish
Carp is in china, koi is in US
Health concerns of carp and koi
Spring viremia of carp- foreign animal disease
Koi herpes virus- endemic to US
*both are reportable
Special needs for clinical exam
Holding units Water quality testing equipment Anesthetic Biopsy and necropsy equipment Microscope
Holding units
Cooler and an air pump
Aquarium system if seeing lots of fish
Anesthesia and restraint
Manual restraint- special nets, handling techniques
Chemical restraint- bath vs injection
Anesthesia- MS222, clove oil
MS-222
Only anesthetic agent approved in fish
Disadvantage is withdrawal time is 21 days so not good for commercial fisheries for food
Sites for blood collection
Caudal vein- most common
Duct of cuvier
Dorsal aorta
Heart- not for survival procedures
IM injection
Muscle lateral to dorsal fin
Blood collection tube
Lithium heparin preferred because EDTA lyses RBCs
How to transport live sick fish
Sturdy plastic bag
Low amount of water with high amount of air
How to transport dead fish
Choose fish with good condition and clear eyes
Wrap fish loosely in a paper towel moistened with water from pond
Place wrapped fish in sturdy plastic bag securely closed
Put bagged fish in shipping container on ice or ice packs
Limiting factor for care
Life support
When should you do biopsy
Before anesthesia if possible
