Hybrid Striped Bass: Spawning

Dr. Craig Kasper Hillsborough Community College FAS 1012 Aquaculture

General Production

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

Morone

spp.:Reproduction

• Broodstock • Egg maturation • Fry management • Fingerlings

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.

HSB: Egg Collection & Staging

• Sampling begins 16 hrs. post inject.(3 mm o.d. cath.) • • Check @ 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!!

HSB: Stripping/Fertilization

• Wet method -strip eggs into metal pan with H 2 O -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

HSB: Incubation/Hatching

• Eggs are sticky (good in wild, but

• Broodstock Future: Physiology and Biochemistry – Determination of Essential Fatty Acids (EFA) – Egg Quality – Fry Survivability • Phase-I, II, III Fishes – EFA’s – Isoflavones –

α

-Tocopherol – Phosphatidylcholine • Metabolism

CHANNEL CATFISH CULTURE IN THE UNITED STATES

BY Leonard Lovshin Department of Fisheries and Allied Aquacultures Auburn University, AL 36849

Channel Catfish ( Ictalurus punctatus )

Native Range of Channel Catfish in the United States

Food Habits

Preferred Habitat

Rivers Reservoirs and lakes

MaximumWeight

The world angling record is 26.4 kg caught in Santee Cooper reservoir, South Carolina

Reproductive Live History

1. Sexual maturity is reached in 2 to 3 years in the southeastern U. S.

2. Spawning takes place in a cavity formed by rocks, logs or a hole in a lake or river bank.

3. Preferred spawning water temperatures: 21-29 C, with optimal temperature 24 to 26 C.

Sexual behavior

1. Males defend a territory/cavity.

2. Female enters the cavity and spawns.

3. Males incubate eggs and defend fry.

4. Males can spawn with more than one female a season.

Spawning cavity

Catfish are grown in 4 to 10 ha earthen ponds with flat bottoms.

Catfish ponds are filled with either:

Filtered surface water or rainfall Well water

Spawning in captivity:

1. Stock adults 3 to 8 years old 2. Stock 1 male to 2 females 3. Stock 800 kg of brooders/ha male female

Spawning Containers

Ammo cans Boxes in spawning pond float Wooden box Milk cans

Spawning occurs during May and June in the Southeastern U. S. Spawning cans are checked every 2 to 3 days for spawns.

Hatching Shed Eggs are transported to a hatching shed.

Eggs are placed in 5-mm square wire mesh baskets suspended in a paddlewheel incubator.

Eggs hatch in 5 to 6 days at water temperatures of 24 to 26 °C.

Fry are placed in screen boxes or troughs for 7 to 14 days before stocking in ponds.

Fry are fed powdered feed.

Screen bottom boxes Fiberglass trough

Fry are stocked at 150,000 to 250,000/ha and grown for 5 months.

Fry are fed powdered, crumbled and pelleted feeds.

Fingerlings are stocked in fattening ponds during January to March. Stocking density is 15,000 to 20,000/ha.

Catfish feed is purchased by the bag or delivered in bulk and stored in silos.

Floating pellets are distributed by a feed blower mounted on a truck.

Floating pellets corn wheat soybean

Feed amount is controlled by an electronic scale located in the truck cab. Catfish are fed what they will eat up to a maximum of 120 kg/ha/day.

Dissolved oxygen concentration is checked night and day to assure that levels remain above 2 mg/l.

Electric (fixed) and tractor (mobile) powered paddlewheels are used to increase D. O. levels.

No water exchange is practiced because ponds are large and pumping water is costly.

Low D. O. can kill catfish within 1 or 2 hours.

Many diseases cause fish mortality.

Birds consume many fish in some regions.

Shoo !

Gas cannon to scare the birds

Catfish are removed from the pond with a seine stored on a hydraulic reel powered by a tractor.

Management systems used:

•

1.

Monoharvest

•

All catfish are removed from the pond when they reach 0.5 to 1.0 kg, 6 to 12 months from stocking. Ponds are drained yearly.

• • •

2. Multi-harvest Only catfish larger than 0.5 kg are removed by partial seine harvest.

Ponds are restocked yearly with small catfish. Large and small catfish are in the pond together. Ponds are partial harvested 2 to 3 times per year. Ponds are drained every 5 to 8 years.

Catfish are retained in a holding net overnight to eliminate small catfish. Fish are crowded for loading onto the transport truck. A crew of 5 can load 15,000 kg of fish in 1 hour.

Catfish are weighed onto trucks taking the fish to the processing factory. Each basket holds 900 kg of fish.

scale

Fish are checked for off-flavor 2 weeks, 1 day and upon arrival at the processor. Off-flavor fish are not harvested.

Catfish are weighed a second time upon arrival at the processor. Fish arrive alive.

scale

Catfish are cleaned, filleted and frozen by the processor.

whole Processed forms as a percentage of total catfish processed: steaks strips Fillets and nuggets 1. Whole - 20 % 2. Pieces and bellies - 20% 3. Fillets - 60 % Preservation method as a percentage of total catfish processed: 1. iced - 20 % 2. frozen - 80 %

The catfish industry maintains a quality control program to insure the consumer a fresh and healthy product.

Principle farming states are located in the Southeastern U. S.. Mississippi (MS) Alabama (AL) and Arkansas (AR) produce 90 % of the farmed catfish.

Mississippi accounts for 65 % of farmed catfish

The channel catfish industry developed in the Southeast because: 1. Popular food fish - market 2. Warm climate 3. Abundant water and clay soils 4. Close to major grain farming regions - cheap fish feeds

Pond yield 4,000 to 7,000 kg/ha/year

Channel Catfish Growth in Live Weight Processed and Average Price per Kilogram, 1970 - 2002 YEAR ------ 1970 1975 1980 1985 1990 1995 1999 2000 2001 LIVE WEIGHT PROCESSED, KG -------------------- 2,609,545 7,336,363 21,120,000 87,098,181 163,636,360 203,130,000 271,194,000 269,819,540 AVG. PRICE * PER KG, $US. ---------------- 0.75

1.09 1.50 1.58

1.69

1.74

1.63

1.65

271,141,272 1.43

2002 286,636,810 1.25

* Price to farmer for fish delivered to the processing plant

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