Overview of Sunfish Culture in the U'S'

1
Overview of Sunfish Culture in the U.S.

• J. E. Morris and C. C. Mischke
• Iowa State University

2
Level of Demand

• Established sport fish in many states
• Bluegill listed as one of top three species
  wanted for purchase in MI

3
Current Supply

• Some wild harvests in Canada
• Limited supply from aquaculture

4
Current Production

• 1999 Buyers Guide - Aquaculture Magazine
• Lepomis producers
• 65 bluegill
• 34 hybrid bluegill (sunfish) fingerling
• 5 hybrid bluegill market size
• other species include green sunfish, longear,
  pumpkinseed and redear
• Pomoxis producers
• 24 black crappie
• 2 white crappie

5
Lepomis spp.

• Bluegill (L. macrochirus)
• Green sunfish (L. cyanellus)
• Redear sunfish (L. microlophus)
• Pumkinseed sunfish (L. gibbosus)
• Longear sunfish (L. megalotis)

6
Pomoxis spp.

• Black crappie (P. nigromaculatus)
• White crappie (P. annularis)

7
Biology Review

• Reproduction
• male attracts female to nest, fertilizes the eggs
  and then drives the female off
• each female may produce more than 80,000 eggs/yr
  in several successive spawns

8
Production of Hybrids

• Most popular hybrid currently produced by private
  fish farmers is the female green sunfish X male
  bluegill cross
• F1 offspring with skewed sex ratios
• reduced reproductive potential

9
Biology Review

• Production of polyploid fish Garling (MSU) and
  Sheehan (SIU-C)
• pressure shocks to induce triploid sunfishes
• cold shocks to induce tetraploid bluegill

10
Biology Review

• Reproduction
• Larvae Culture
• fry hatch in 24-36 hours at 23 OC
• initial length at hatching is 3-4 mm
• yolk absorption and swim-up at 7-days post-hatch

11
Conclusions from ISU Study

• Larval bluegill can not digest commercial feed at
  onset of exogenous feeding, but hybrid sunfish
  can
• Larvae fed Biokyowa had the best survival
• In general, the longer larvae are fed Artemia,
  the better the growth and survival

12
Biology Review

• Reproduction
• Larvae culture
• Growout methods
• ponds (most popular)
• 12,355-17,297 fish/ha (5,000-7,000 fish/acre)
• cages
• 200 fish/m3 (6 fish/ft3)

13
Biology Review

• Growout methods - continued
• recirculating systems
• Overview
• May be able to produce fingerlings for resale
  within months of hatching
• 2 years to reach food size 227-340 g (1/2-3/4
  lb)
• Optimal growth at 18-23 oC (64-73 oF)

14
Biology Review

• Reproduction
• Larvae culture
• Growout methods
• Feeds
• gt40 protein (recirculating systems)
• gt32 protein (ponds)

15
Biology Review

• Reproduction
• Larvae culture
• Growout methods
• Feeds
• Processing
• limited study indicated a 30 dress-out for fillet

16
Biology Review

• Reproduction
• Larvae culture
• Growout methods
• Feeds
• Processing
• Marketing
• fingerlings 2-3 inches
• food 227-340 g (1/2-3/4 lb)

17
Species Advantages and Attributes

• Acceptance of commercial diets
• Good growth rates
• Temperature tolerance
• Ability to spawn more than once per year
• Consumer acceptance

18
Disadvantages

• No diets specifically made for them
• Sexual maturity at small body size
• Often spawn multiple times in pond resulting in a
  large number of small fish

19
Research Needs for Scale-up

• Nutrition
• Genetics
• Determination of species or hybrids best suited
  for aquaculture
• Market studies
• Economic studies

20
Current Researchers

• North Central Regional Aquaculture Center
• nutrition
• Brown (Purdue University), Garling (MSU), Kohler
  (SIU-C)
• market size
• Morris and Summerfelt (ISU), Hayword
  (UM-Columbia), Triplett (PSU), Kohler (SIU-C),
  Sheehan (SIU-C), Malison (UW-Madison)
• physiology
• Barton (USD), Malison (UW-Madison)

21
Current Researchers

• Other regions
• Manipulation of sex ratios
• Phelps (Auburn U)
• General Culture
• Kleinholz (Langston U)

22
Species Selection

• ? bluegill X ? green sunfish F1 hybrids appear to
  be best candidates for aquaculture.
• Black crappie out perform both white crappie and
  hybrid crappie.

23
Conclusions