pre-midterm

Question 1

what happens if you pond salmonids too soon?

Answer 1

the fry sit on the bottom in feed. this leads to BGD (bacterial gill disease)

Question 2

what happens if you pond salmonids too late?

Answer 2

leads to cuts and scrapes and fungus

Question 3

What are the factors of a poor incubation?

Answer 3

• excessive incubator flow
• light exposure
• no substrate
• physical disturbance
• low oxygen
• sudden temperature changes
• high ammonia levels
• gas supersaturation

Question 4

MAWW

Answer 4

maximum alevin wet weight (as yolk is absorbed the alevin get heavier until they reach MAWW)

Question 5

what is MAWW an indicator of?

Answer 5

• coincides with gravel emergence
• should start food
• different egg sizes take different amount of time to MAWW

Question 6

Belehradek model: formula, what it means

Answer 6

D=a/(T-C)b

D= Days to MAWW
T= Temperature
abc= constants

Question 7

what is the formula for ATU’s?

Answer 7

ATU= TxD= T(a/(T-c)b)

ATU’s to MAWW

Question 8

what are the ATUs to MAWW for Chinook?

Answer 8

955

Question 9

what are two requirements for initial ponding containers?

Answer 9

• must control excess feed and recover morts

- must be shallow

Question 10

when should you do an inventory on newly ponded fish?

Answer 10

• wait till fry ~1g

- wait until fry are feeding and growing well

Question 11

what are two methods for taking an inventory of fish?

Answer 11

electronic counters and weight method

Question 12

How do you execute the ‘Weight Method’ of fish inventory?

Answer 12

-fish must be greater or equal to 1g
-must sample every tank
-must crowd the fish
-fill small container with water. weigh or tare.
-add 50-100 fry and re-weigh
-back count into tank
-must take greater or equal to 3 samples
-get the average weight of the three samples
-weigh all the fish in tank
-divide by mean fish weight
=inventory

Question 13

Perpetual inventory

Answer 13

number of fish, minus the morts

Question 14

Ball Park Inventory, what are the two methods

Answer 14

give you an approximate number of fish in the tank

• feeding method
• oxygen consumption

Question 15

what is the feeding method for ball park inventory?

Answer 15

compares food consumption with a tank with known number of fish who should be the same size and on the same water supply. Must be fed by hand to satiation. do this for at least a week. then compare consumption

Question 16

whats oxygen method for ball park inventory?

Answer 16

compares oxygen consumption of known number of fish in one tank to an unknown number tank. both tanks have same water, temperature, fish size, flow rate, and starve for greater than 24 hours. Use winkler titraton for oxygen. look up the formulas for this.