Cockle/Oysters

Question 1

scientific name for cockle

Answer 1

Clinocardium nuttallii

Question 2

why cockles?

Answer 2

• indigenous
• culturally important
• attractive product
• local market
• world markets
• multiple markets
• different grow-out strategies

Question 3

what sort of areas do cockels grow?

Answer 3

sandy, sheltered beaches

Question 4

describe a cockels shell

Answer 4

distinctively rounded shells
bilaterally symmetrical
heart-shaped
radial ribs

Question 5

cockle’s mantle has 3 appertures:

Answer 5

• inhalant
• exhalent
• pedal

Question 6

gonochorism

Answer 6

sex varies with conditions (cockle)

Question 7

Name pros for BC cockle aquaculture

Answer 7

• fastest potential growth rate of any species under consideration
• can be grown off bottom at high densities with great survival
• good response to aquaculture growing conditions
• wide range of physical tolerances
• internationally recognized
• idiginous cultures attachment
• attractive animal
• food quality
• taste
• lack of competition

Question 8

how long does it take a cockle to get to ‘steamer’ product, sushi product?

Answer 8

1 season

2 seasons

Question 9

cons for cockle aquaculture

Answer 9

• market establishment and vertical integration
• short shelf life
• dangerous fishery (21 ppl died..)

Question 10

what are the 4 steps for shellfish culture?

Answer 10

hatchery, nursery, grow-out, market

Question 11

what is in a hatchery?

Answer 11

• broodstock
• larvae
• settle
• algae

Question 12

what sort of tanks do you hold cockle larvae in?

Answer 12

upwelling larval rearing tanks, downwelling seed tanks

Question 13

name considerations for broodstock with shellfish aquaculture

Answer 13

-why are the brood important
-where do you get them from
-how many do you use
-sexual type matter?
(protrandic and functional hermaphrodites, alternate)
-benefits of conditioning
-temperature matter?
-food needed?
-season?

Question 14

name some larval food determinations when setting up a shellfish hatchery

Answer 14

• suitable dietary items for larvae and post larvae
• optimal food ration for larvae and post larvae
• optimal rearing temp for larvae and post larvae
• optimal stocking densities of r larvae and post larvae

Question 15

what are some potential hatchery problems when rearing shellfish?

Answer 15

Factors affecting growth/survival:

-temp, salinity, seawater quality, tolerances outside of wild range, egg/larval quality, disease (bacteria, response)

Question 16

what virus causes the most mortalities with shellfish?

Answer 16

Vibrio tubiashii

Question 17

What is our native oyster?

Answer 17

Olympia oyster,

Ostrea conchaphila

Question 18

what defines the eastern oyster?

Answer 18

inside smooth shell with blue, black or brown adductor scar. Pear shaped, sooth shell, concentric.

Question 19

when was Crassostrea gigas introduced to BC, and where?

Answer 19

Ladysmith, 1912/1913

Question 20

Describe the reproductive parameters of Crassostrea

Answer 20

• broadcast spawners
• external fertilization
• oviparous
• gonochoric

Question 21

how is it that Crassostrea can tolerate more turbid conditions?

Answer 21

• left attachched valves forms a deep bowl
• promyal chamber
• posterior placement of adductor capable of rabid and powerful contactions, which allow it to eject a stream of water to wash out the mantle and gills.

Question 22

2 things to insert into an oyster for pearl formation

Answer 22

sand gran

parasite

Question 23

how long does it take to make a seeded pearl? a bead pearl?

Answer 23

seeded: 3 years
bead: quickly

Question 24

FLUPSY:

name, powered by what

Answer 24

floating upwelling system

powered by tidal, solar, generator.

Question 25

name the different oyster aquafarming grow-out methods

Answer 25

• long lines and floats
• bobs
• rafts
• tumbling

Question 26

why triploid oysters?

Answer 26

if they survive:

• grow faster
• larger than diploid
• sterile oysters
• marketable year round
• diploid spawny in summer
• 80% viable eggs successfully triploid

Question 27

what are the mortality losses for triploiding oysters?

Answer 27

50-70% in the first 4 days of life