fish Flashcards
Summarize the basic management requirements of farmed and ornamental fish
- water quality (susceptible to sudden changes in water quality and composition especially salt), freshwater species more tolerant. factors include oxygen, carbon dioxide, temp, nitrite, nitrate, pH, hardness, salinity, chlorine, toxins (most important are o2/co2/notrogen cycle (ammonia, nitrite, nittrate)
- nitrogen cycle: ammonia converted to nitrite by bacteria, converted to nitrate by bacteria. nitrite and ammonia both toxic to fish
- environment: number of fish, species compatibility, enrishment, plants, hiding spots
- temperature controls based on species
- nutrition should be tailored to type of fish in aquarium (carnivores vs herbivores and omnivores). herbivores require less nutrient dens diet and have longer intestines to allow absoption and digestion of vegetable material, carnivores need nutrionally dense high protein diets, live feed?)
Recognize the physiology and anatomy typical of many fish species, whilst acknowledging that significant differences in anatomy and physiology exist across fish species.
external:
- operculum: protective gill cover involved in buccal pump
- caudal fin for locomotion and foreward momentum
- dorsal fin: keeps fish upright, controls direction of movement
- anal fin keeps fish stable and upright
- pectoral/pelvic fins: used for steering, balance and moving up and down in the water
- lateral line: system of sense organs to detect movement, vibration, pressure gradients
- skin: barrier to environment, osmotic barrier, lubricant (mucous layer) defence against pathogens
internal:
- GIT: simple in short in carnivores, longer in herbivores
- liver
- anterior coelom (largest organ)
- some fish have hepatopancreas
- others have opancrease seperate to liver
- kidney (lots of species variation
gills:
- site of gas exchange
- acid base balance
- excretion of nitrogenous wastes
- osmoregulation
heart: different shapes and sizes in different species. recieves oxygenated blood from gills and pumps around the body
swim bladder: mechanism for maintaining bouyancy and position, not present in all species. 2 types:
- physostomous attached to GI system (entry and exit of gases)
- physoclistous - gas glands for gas exchange with blood. takes longer to fill or empty
Discuss fish welfare and locate legislation applicable to fish
- welfare assessed based on stocking density, feeding rates, behaviour, growth rate, health status, survival rate, surface activity, water quality
- standards established by FAO’s code of conduct for responsible fisheries, aquaculture stewardship council, RSPCA, organic certification schemes, SSPO code of good practice
- legislations: animal welfare act 2006, animal sentience act 2022
Provide details of some of the common disease challenges faced by fish keepers/farmers in the UK and measures taken to prevent them
- dropsy = bouyancy problems
- tumours
- dystocia/egg binding
Describe the main groups of seafood including fish, crustaceans, molluscs, cephalopods, other invertebrates
finfish
- salmonoids (atlantic, pacific salmon and trout)
- freshwater (carp, catfish, tilapia)
- marine species (bream, bass, cod, halibut and more)
shellfish:
- crustaceans (crab, lobster, shrimp, barnacle)
- mulluscs (cephalopods such as squid, octopus, cuttlefish, bivalves such as clams and oysters, gastropods such as whelks and winkles)
- echinoderms (sea urchins)
Describe how you would safely obtain a diagnostic blood sample from a fish
from tail vein, ensure lab sending to can interpret fish results, 90 degree
describe the body plan of a mullosc
- foot
- radula (toothy tongue)
- mantle (produces shell)
- shell
- visceral mass (internal organs)
what is a flow through water management system
marine or freshwater systems commonly used in the famring of salmonoids, bass, bream, halibut etc
what is a recirculation water management system
marine or freshwater commonly used in juvenile production of salmonoids, sole, bass, bream, shrimp, etc.
what is a batch cultuture water management system
shrimp, marine fish early larval rearinf
what are pond aquaculture systems
- enclosed water areas
- most commonly used
- lest intense
- depend on natural processes
- commonly house salmonoids, shrimp etc
what is a raceway aquaculture management system
- rectangular structures
- single pass system
- built above or below ground
- require large volumes of water
- gravity flow
- species such as trout, carp and prawns typically housed
what is a cage aquaculture management system
- a flow through system
- easy to stock, feed and harvest
- circular or square cages in ocean or fresh bodies of water vary in size, made of soft or hard materials
- disadvantages: little environmental control, susceptible to predators, exposure to water borne irritants, exposed to bad weather conditions, limited qater quality control
- species such as salmonoids, seabass etc housed
what is a recirculating aquaculture system
- most intensive system
- can be located almost anywhere
- less water requirement
- significant energy input
- require expertise
- expensive
- commonly used in juvenile stages
- species such as salmon, trout, eels, sturgeon etc housed
what are poles, racks, rafts and longline aquaculture housing systems
- used in mullosc aquaculture
- essential that area/location is right (avoid winds, need correct water depth and movement, should be phytoplanktin rich with no toxic wastes
- poles literally poles drilled into sea bed with mulloscs growing around, racks suspended, rafts raft
