227 Flashcards
list four perceived problems with net pen farming of salmon that are often raised by environmental non-govermental organizations
i) desease spread
ii) over fishing of meal fish
iii) pollutants
iv) feral fish competing with wild stocks
what is the minimum size at which an Altantic salmon can be expected to smolt and tolerate sea water?
50g
how many winers do chinook salmon jacks spend in sea water?
1 year
what size to chinook smelt?
5-15g
how many witnters would you expect a south coastal, ocean type chinook salmon to spend in freshwater before smelting?
2-4 years
3 modes of gene action that may occur in a population
i) additive
ii) dominance
iii) epistatic
what is the minimum value for heritability to make a selective breeding program worth undertaking?
0.2
Genetic Drift
not enough chromosomes to keep genetic variance
effective breeding number (quick def)
number of chromosome compositions in a group
what is the relationship between genetic drift and effective breeding number?
in order to prevent genetic drift, you must maintain an effective breeding number.
When do you want to maintain genetic varience, and when do you want to limit it?
maintain: wild stocks
limit: private breeding stocks
success of selective breeding depends on
heritability of the trait
Heritability
proportion of phenotypic variation due to additive genetic variance
what is the formula for heritability
xbar selects - xbar population
when establising a line breeding program, why should the males and females be taken from different stocks?
difficult and expensive to maintain
when sorting female salmonid brook stock for ripeness, what three categories should they be sorted into?
green, ripening, ripe
effective breeding number (formula)
Ne= 4(female)(male)
——————–
female +male
inbreeding in one generation (formula)
f= 1
——–
2Ne
what is the minimum effective breeding number?
2
what formula should be used for the following question: Given a maranil stock solution of 20,000 mg/L, a desired anaesthetic concentration of 5mg/L and a stun tank that holds 500 L, how much stock solution should be used for the aneasthetic bath?
L= (CDxV)/Cs
which anaesthetic must be used when sorting brood fish that may later be used for human consumption?
CO2
name 9 ways of capturing brood stock
i) seining
ii) gill nets
iii) electrofishing
iv) angling
v) fences/weirs
vi) tail snare
vii) fish wheel
viii) imprinting
xi) brood holding
name 4 types of anesthetics
maranill, ms222, co2, clove oil
how much sedation would you add when transferring brood?
1/3 - 1/5 ppm
fungal treatments
malachite green, formaldehyde
what are the 5 main reasons for controversy regarding salmon farming?
sea lice, meal fish, interbreeding escapees, colonizers, pollution
what are the original species for farmed fish?
brown trout, atlantic salmon
what is the very first salmon feed?
OMP
what nation was the first to take up commercial salmon farming and what was their reason?
norway, because of the destruction of the fishing industry
where were the first two salmon farming operations in BC, and why didi they fail?
tidal rush, Roy Pac. ‘83, holes in nets, algae bloom
how many mT/year does BC’s samon farming industry produce per year?
80,000 to 100,000 mT annually
how much does the east coast produce?
20-30 mT/year
who are the 4 main players in BC farming?
mainstream, creative, marine harvest, greig
what is the annual global estimation of total salmon production?
1.7-2mill tonnes/year
3 environmental stimuli
photoperiod, temperature, food
sensors
eyes, pineal gland, nutritrional sensors
What happens in the brain?
hypothalamus secretes GTHRH to the pituitary, which in turns secretes GTH
GTH affects what?
gonads, sex steroids,ovulation
what are the 2 sex steroids?
17Bestradiol, 11ketotestosterone
sex steroids messages what 2 things?
liver, makes lipids and vitellogenin, also the Soma.
Soma
secondary sexual traits, spawning behaviro and aggression
Photoperiod
rate of change, change of direction
female cycle
initiation of gonadal maturation, exogenous vittelogenesis, endogenous vittelogenesis, secondary sexual traits, final oocyte maturation, ovulation, spawning.
what is the composition of artificial ovarian fluid used to wash contaminated salmonid eggs?
14gNaHCO3/LH20
which two salmonid species are most widely cultured around the world?
mykiss and salar
how can triploid fish be differentiated from diploid fish?
size of cell
how do male and female troploid salmonids differ from one another at the age of sexual maturity?
males develop secondary sexual traits
for how long would you expect a salmonid sperm cell to be active in freshwater?
30-90 seconds
Briefly describe how triploidy is usually obtained in rainbow trout eggs fertilized with normal milt. Include timing of the recommended procedures
normal eggs:normal milt. shock for 10-20 minutes, 10-40 minutes post fertilization
what is the other method than ATUs?
Belehradek model
1mmHg =
1 TORR
2 methods of measuring O2
Azide modified winkler’s titration, hach kit
If incubator oxygen levels are too low, what do you do?
lower temperature, up the flow rate, add pure oxygen to inflow, reduce number of eggs
what causes gas supersaturation?
well water, water from dam spillways and waterfalls, low pressure systems, mixing cold and warm water, snow melt, excess phytoplankton
factors changing pH
CO2 from respiration, pH goes down. CO2 from photosynthesis, pH goes up. Alkalinity
Suspended solids and Organic Debris
down resperatory rate, down flow rates and cause chanelling, down disinfectant usefulness, down vector for pesticides and metals, causes gill mucus production and lowered O2 uptakes, interferes with feeding, Ups BOD and causes O2 to go Down.
what are the three graph points of Pc? what are the associated degree days?
(5,3) (7,7) (10.5,9) 364, 319, 225 (just eyed)
what is the x and y for oxygen uptake graph?
x= ambient oxygen level (mg/L) y= oxygen uptake (ug/individual/h)
