Hybrid Striped Bass: Spawning

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Hybrid Striped Bass Spawning

• Dr. Craig Kasper
• Hillsborough Community College
• FAS 1012
• Aquaculture

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General Production

• Intensive Extensive
• Enhancing Phase-I Fish
• Ensuring Quality Products

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Morone spp.Reproduction

• Broodstock
• Egg maturation
• Fry management
• Fingerlings

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HSB Broodstock

• Wild adults collected by electrofishing or
  angling.
• Spring spawning (55-68ºF.)
• hormones used
• ?-IM 330 IU hCG/kg bwt.
• ?- only 150 IU hCG/kg bwt.

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HSB Egg Collection Staging

• Sampling begins 16 hrs. post inject.(3 mm o.d.
  cath.)
• Check _at_ 2 hr intervals (narrow window)
• -2 hr sb, 0.5 hr wb
• Look at eggs microscopically
• - eggs blood-free, oil droplet
• coalesced (transparent)
• chorion intact
• - eggs will be brownish
• Bottom line...frequent all nighters!!

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HSB Stripping/Fertilization

• Wet method
• -strip eggs into metal pan with H2O
• -add milt (sperm)
• -sperm is activated by salinity
• shock due to water exposure
• Dry method
• -strip eggs, add sperm,
• stir eggs (turkey feather)
• -add water

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• Striped bass eggs
• shortly after fertilization
• prior to cell division.

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HSB Incubation/Hatching

• Eggs are sticky (good in wild, but ltfucundity)
• -Add bentonite or tannic acid
• Incubate in MacDonald Jars/100K eggs/jar
• Continuous flow of O2 water
• 2-4 days hatch
• Fry swim-up and into traugh
• Stock _at_ 4 days post-hatch (250K/ha)

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Future Physiology and Biochemistry

• Broodstock
• Determination of Essential Fatty Acids (EFA)
• Egg Quality
• Fry Survivability
• Phase-I, II, III Fishes
• EFAs
• Isoflavones
• a-Tocopherol
• Phosphatidylcholine
• Metabolism

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Culture of Hybrid Striped Bass In the U. S.
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Striped Bass ( Morone saxatilis )
Popular sport fish caught in U. S. marine coastal
waters
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Distribution of Striped Bass in U. S.
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Life History Food habits -
Predacious
Lives in saltwater but spawning is in freshwater
( anadromous ). Migrates up coastal rivers in the
Spring. Several land-locked populations are
established in U.S. Males and females reach
sexual maturity in 3 years and 4 years,
respectively. Life span is 30 to 40 years.
Reproduction -
Growth -
Reaches 32 kg in ocean
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Commercial Fishery Striped bass is a prized
sport and food fish. The commercial catch dropped
from 15 million lb in 1973 to less than 1 million
lb in 1989. Presently, the commercial catch is
about 6 million lb/yr. Sport and commercial
fisheries are heavily regulated. Fingerling
stocking programs into fresh and salt water began
in the early 1970s
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White Bass ( Morone chrysops )
Life History
Food habits predacious Growth 4 to 5 lb in
freshwater lakes Reproduction Lives and spawns
in fresh water. Migrates up rivers and streams to
shoal areas in Spring to spawn. Males and females
reach sexual maturity in 2 and 3 years,
repectively. Life span is 5 to 6 years.
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Distribution of white bass in U. S.
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How to distinguish among striped, white and
hybrid basses
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Hybrid Striped Bass
Palmetto bass Striped bass female x white
bass male Original cross first performed in the
mid 1960s
Sunshine bass Striped bass male x white bass
female
Both hybrid crosses are stocked into fresh waters
to improve sport fishing. Both crosses are
fertile and will reproduce in natural waters with
adequate spawning habitat. The sunshine bass is
the most widely cultured hybrid because it is
easiest to produce fingerlings. Hybrids are
better for culture than striped bass because they
are more resistant to handling and warm water
temperatures in culture units. Hybrids grow
faster than white bass and will reach 20 lbs in
natural waters.
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Water quality for hybrid striped bass Water
temperature 1 to 33o C optimum for growth is
25 - 27oC Salinity 0 to 25 ppt Dissolved Oxygen
optimum is 6 12 mg/l can withstand 1 mg/l
for short periods Alkalinity and Hardness grow
best in waters above 100 mg/l pH 7.0 to 8.5
ideal
Salt is added to freshwater with low cloride ion
concentration to improve growth and survival
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Reproduction in Captivity Spawning water
temperatures 15 to 21oC Obtaining
broodfish White bass Some domestigated stocks
but most are captured from the wild with nets and
hook and line. Striped bass Domestigated
brooders not available, all are captured from the
wild. Only state and federal agencies can use
nets and electrofishing. Private producers must
catch brooders by hook and line and transport
them to the hatchery.
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Spawning Males and females are injected with
hormones to obtain eggs and sperm. Eggs can be
checked to determine if they are ripe and ready
for fertilization.
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Spawning - Eggs are stripped from females and
mixed with sperm from the males. White bass eggs
are adhesive and must be treated to remove
adhesiveness before placement in incubators.
Striped bass eggs are non-adhesive and need no
treatment.
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Egg incubation McDonald jars are used to
incubate the eggs. Eggs hatch in 40 to 48 hr
after fertilization in 15 to 18o C water. Fry
begin to feed 4 to 8 days after hatch. Fry are
about 1mm at hatch.
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Nursery Phase First food Palmetto bass
large zooplankton ( daphnia ) Sunshine
bass small zooplankton ( rotifers )
Ponds must be carefully filled and fertilized to
prepare the proper food organizm for the type of
hybrid fry stocked Stocking rate 250,000 to
500,000/ha
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Nursery Phase Survival to 35 to 50 mm in 3 to
4 weeks of culture Palmetto bass 40 to 50
Sunshine bass 10 to 25 Feed training
In ponds Crumbled feed can be fed to 14 to 21
day-old fingerlings. Bass will learn to
eat feed. In tanks Remove 4 week-old
fingerlings from ponds and stock them at high
densities in tanks receiving flowing water.
Feed them nutritionally complete crumbled diets.
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Growout Phase I Grading fingerlings must be
graded to reduce cannibalism before stocking.
Stocking density 20,000 to 50,000/ha in earthen
ponds Feeding Bass are feed a 40 protein
floating diet 1 to 3 times/day starting a 5 body
weight/day, reduced to 3 /day as the bass grow.

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Harvest Bass are harvested in the winter when
water temperatures a cold. Survival is 85 and
average weight is 125 to 225 g.
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Growout Phase II Stocking Bass are graded and
stocked at 3,000 to 4,000/ha into
earthen ponds. Feeding Bass are fed 1 to 3
body weight daily with a 40 protein
floating diet. Harvest Bass reach 1.25 to
1.5 lb with a survival of 90 by
October - November. Yields 4,000 to 5,000
kg/ha with aeration. 55 of the hybrid
striped bass harvest in the U. S. are
grown in ponds.
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Growout Phase II
Hybrid striped bass are also grown in tanks at
high density
45 of the hybrid striped bass harvested in the
U. S. are from tanks
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Markets - 1999 Live 11 of U. S. harvest is
marketed live as food fish or for fee fishing.
Price to farmers is 3.30/lb ( 7.26/kg ).
Fresh 89 of U. S. harvest is sold whole on
ice. Price to farmers is 2.53/lb
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• Constraints
• Competition from striped bass commercial fishery
• High cost of production high market price
• Difficulty obtaining broodfish
• Legal restrictions to sell cultured hybrid
  striped bass in many states because it is
  considered a sport fish. Each fish must be
  individually tagged.

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U. S. harvest - 1999
Weight - 9.7 million lbs (4.4 million kg
) Value - 28 million
Hybrid striped bass is 5th in weight of food fish
harvested in the U. S.
THE END