Trends in Hybridization Rates of Crappies (Pomoxis) in a Minnesota Lake

1
Trends in Hybridization Rates of Crappies
(Pomoxis) in a Minnesota Lake

• Michael Lew
• 2005

2
Introduction

• There are two types of crappies
• Black (Pomoxis nigromaculatus)
• White (Pomoxis annularis)

Source http//sites.state.pa.us/PA_Exec/Fish_Boat
/pafish/blcrappm.jpg
Source http//sites.state.pa.us/PA_Exec/Fish_Boat
/pafish/whcrappm.jpg
3
Introduction

• They sometimes cross-breed, forming a hybrid
  crappie
• F1 A hybrid with one Black and one White parent
• Fx A hybrid with at least one hybrid parent

4
Introduction

• Travnichek et al. studied ten Alabama reservoirs
  from 1992 to 1995
• Found first-generation hybrid and advanced hybrid
  crappies
• Proved hybrid crappies were fertile

5
Introduction

• Smith et al. studied Weiss Lake, Alabama from
  1990 to 1991
• Found that first-generation hybrids grew faster
  in length to 254 mm than parent white or black
  crappies
• Found that advanced hybrids grew slower in length
  to 254 mm than first-generation hybrids

6
Introduction

• Hooe and Buck et al. studied crappies in small
  aquaria from 1984 to 1989
• Found that first-generation hybrids outgrew
  parent white and black crappies over a period of
  three years
• Found that advanced hybrids grew slower than
  first-generation hybrids over a period of three
  years

7
Introduction

• Crappies studied were from Fox Lake, Minnesota
• Years 1998, 1999, 2000, 2001, and 2002 were
  studied
• Part of a DNR goal to determine each lakes
  potential to produce large crappies

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Goals

• Determine trends in the rate of hybridization
  over five years
• Determine effects of hybridization on growth of
  the four categories (white, black, F1, and Fx) of
  crappies

9
Methods

• Preparation of Scale Samples
• 5 Chelex solution
• Incubated at 56C overnight
• Polymerase Chain Reaction
• 10x Buffer
• 25 mM MgCl2
• 10 mM dNTPs
• 100 mM Primer LMA 104, LMA 117s, MS 13, LMA 21
• Taq

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Methods

• Gel Electrophoresis
• 10x TBE
• Acrylamide
• TEMED
• Ammonium Persulfate
• Gel Staining
• SYBR Gold Nucleic Acid Gel Stain
• UV Light Box

11
Results
12
Results
13
Results
14
Results
15
Discussion

• Fx crappies grew similar in length to white
  crappies
• Age 0 p 0.0765
• Age 1 p 0.838
• Age 2 p 0.0450
• Age 3 p 0.331

16
Discussion

• Fx crappies grew similar in length to F1 crappies
• Age 1 p 0.180
• Age 2 p 0.668

17
Discussion

• Fx crappies grew larger in length than black
  crappies
• Age 0 p 0.00377
• Age 1 p 0.0629
• Age 2 p 0.0144
• Age 3 p 0.224

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Discussion

• F1 crappies grew larger in length than white
  crappies
• Age 1 p 0.0392
• Age 2 p 0.00986

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Discussion

• F1 crappies grew larger in length than black
  crappies
• Age 1 p 0.0000658
• Age 2 p 0.00306

20
Discussion

• Not enough data for F1 analysis for ages 0 and 3
• Age 3 comparisons all had p-values higher than
  the significance value (p lt 0.05)

21
Discussion

• Rate of hybridization was 10.5, but not steady
  over the five years

22
Practical Analysis

• F1 hybrid crappies could be used for stocking
  lakes
• Crappies are a popular sport fish and pan fish
• Over fishing by the human population or a winter
  kill-off could present the need for stocking
• F1 crappies grew significantly larger than parent
  white or black crappies
• F1 crappies are fertile

23
Further Study

• Collect scale samples from every third, fourth,
  or fifth fish to ensure that data represents fish
  population more accurately
• Collect climate data at the lake to determine if
  there are effects of weather on hybridization

24
Acknowledgments

• Dr. Loren Miller
• Ms. Lois Fruen
• Team Research
• Mr. Brad Peterson
• Dave Carroffino
• Jason Roloff

25
Trends in Hybridization Rates of Crappies
(Pomoxis) in a Minnesota Lake

• Michael Lew
• 2005

Source http//sites.state.pa.us/PA_Exec/Fish_Boat
/pafish/blcrappm.jpg
Source http//sites.state.pa.us/PA_Exec/Fish_Boat
/pafish/whcrappm.jpg