Download Propagating and Selling Fish

Propagating and Selling Fish!
Next Generation Science / Common Core Standards Addressed
• HS‐LS2‐6.Evaluate the claims, evidence, and reasoning that the
complex interactions in eco systems maintain relatively consistent
numbers and types of organisms in stable conditions, but changing
conditions may result in a new ecosystem.
• HS‐LS4‐5. Evaluate the evidence supporting claims that changes in
environmental conditions may result in: (1) increases in the number
of individuals of some species, (2) the emergence of new species
over time, and (3) the extinction of other species. [Clarification
Statement: Emphasis is on determining cause and effect
relationships for how changes to the environment such as
deforestation, fishing, application of fertilizers, drought, flood, and
the rate of change of the environment affect distribution or
disappearance of traits in species.
Bell Work / Objectives
•
•
•
•
Identify propagation methods of fish.
Describe how to care for fry.
Identify strategies for marketing fish.
Identify factors that affect selling fish.
Terms
•
•
•
•
•
•
•
Artificial spawning
Broodfish
Farm spawning
Fingerlings
Fry
Live haulers
Milt
•
•
•
•
•
•
•
Mouthbrooders
Natural spawning
Photoperiod
Propagation
Spawning
Spawning container
Substrate spawning
Propagating and Selling Fish
• What product does a cattle rancher sell?
• What product does a hog farmer sell?
• What product does a fish farmer sell?
How are fish propagated?
• Propagation
– Process of man controlling fish reproduction.
• Fish reproduce by spawning.
– Female lays her eggs and then the male
deposits sperm over the eggs.
• Method’s of propagating fish vary by
species.
Catfish propagating
• Often allowed to naturally spawn
– Without the intervention of man.
– Female seeks a hollow structure to lay eggs.
• Can use farm spawning
– Occurs when male and female catfish are
moved to a spawning container.
• Artificial nest
– Fertilized eggs can be left in pond or moved
to hatchery.
– Eggs will hatch in 6 to 10 days.
Spawning Containers
Tilapia propagating
• Usually spawned in ponds, tanks or
aquaria.
• Spawning controlled by photoperiod.
– Number of hours of sunlight during a day.
• Spawn when days reach 10 to 16 hours.
• Spawning can be controlled by artificial
lights.
Tilapia propagating
• Mouthbrooder
– Lay eggs in
nest.
– Allow eggs to
be fertilized.
– Female will
incubate eggs
in mouth until
hatched.
• Substrate
spawning
– Lay eggs in
their nests on
bottom of
pond.
– Eggs are
fertilized.
– Eggs remain
on the bottom
to hatch.
Trout propagating
• Can spawn naturally but usually incubated
commercially.
• Trout eggs take 80 days to hatch.
• Often propagated by artificial spawning.
– Eggs are removed from female.
– Milt (sperm) is removed from male.
– Humans mix the eggs and milt together.
– Fertilized eggs placed in incubators.
– Eggs are monitored and controlled.
How should fry be cared for?
• Fry
– Immature fish
– Must be protected
from predators in
natural spawning.
– Dietary
requirements are
different than adult
fish.
How should fry be cared for?
• Fingerlings
– Young fish slightly
larger than human
fingers.
– Ready to be
stocked in ponds.
Catfish fry
• Born with an egg sac that gives
nutrition for a few days.
• After egg sac is gone feed 49%
protein feed that is finely
ground.
• Protein percentage is reduced
as fry matures.
• Fry kept in troughs or other
protected areas for 1 year.
• Then they are considered
fingerlings.
Tilapia fry
• Cared for in similar way as catfish.
• Started on feed that is as high as 60%
protein.
• Feed is usually ground into a fine meal or
pellets that disintegrate in water.
Trout fry
•
•
•
•
•
Cared for similar to catfish and tilapia.
Very small.
After hatching moved to troughs.
Fed a nutritious feed.
Continuously graded to keep fry of similar
size together.
• Done to prevent larger fry from eating the
smaller ones.
What are some strategies for
marketing fish?
• Sell broodfish to hatcheries
– Fish used for breeding.
• Fish hatcheries
– Produce eggs, fry and/or fingerlings sell
these to other producers.
• Obtain eggs or fry from hatcheries.
– Raise them to fingerlings size.
– Sell them to producers to stock ponds.
What are some strategies for
marketing fish?
• Raise the fingerlings to harvest size.
– Sell the fish to processors, fee lake
operators, or live haulers.
• Live haulers
– Buy fish from growers and then resell to
fish markets or fee lakes.
What are some strategies for
marketing fish?
• Fee lake operators
– Obtain fish from
growers.
– Stock ponds.
– Charge people to
fish in their ponds.
What factors affect selling fish?
• Size of the fish
– Should be marketed at optimum size.
– Varies with species and stage they are
marketed.
– Need uniform lots.
– Separate fish by size.
– Numerous mechanical devices can be used to
sort fish.
What factors affect selling fish?
• Grading Fish
– Remove fish that
are diseased or
injured.
– Graded on color.
– Uniform looking lot
of fish is desirable.
Review / Summary
• How are fish propagated?
• How should fry be cared for?
• What are some strategies for marketing
fish?
• What factors affect selling fish?
The End