Statistical Study of Host Fish for the Round Pigtoe Mussel (Plueurobema coccineum)

By Meggie Marzec

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Introduction

• Mussels clean rivers and streams

• Indicate health of river system

• Round Pigtoe threatened in MN, native to St. Croix

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Introduction

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Introduction

Glochidia with and without tissue

Previous studies show there may be a difference

Photo taken by Dr. Miller

Previous Studies

• Spotfin shiner, common shiner and hornyhead chub are host fish

• Golden shiner and creek chub are marginal host fish– From 2003 Host Fish Suitability Trial

Previous StudiesFigure 1 - Number of Glochidia and Juveniles Produced Over

Time for Spotfin Shiner

0

2

4

6

8

10

12

14

0 5 10 15 20 25 30 35 40

Days after Glochidial Infestation

Number of Mussels

w/o tissue

w/ tissue

juveniles

•2003 Study, glochidia without and with tissue as life cycle stages

Goals

• Find which host fish is statistically stronger: hornyhead chub or common shiner

• Find new host fish

• Study glochidia without tissue and with tissue as life cycle stages

Procedure

• Collect host fish and mussels from St. Croix River

• Infest fish with glochidia and check siphonate every three days

• Fish in statistical study kept in individual aquaria

Results

hornyhead chub

total # of glochidia, juveniles

# of juveniles

% transformation

1 82 54 67% 3 101 59 58%

Average Percent Transformation for hornyhead chub 63%

spotfin shiner total # of glochidia,

juveniles # of

juveniles %

transformation 2 70 23 33% 3 47 20 43% 4 102 21 21% 5 59 2 3%

Average Percent Transformation for spotfin shiner 25%

Table 1: Percent Transformation for hornyhead chub and spotfin shiner

Results

Figure 2 - Number of Glochidia and Juveniles Produced Over Time for Common Shiner

0

20

40

60

80

100

120

0 5 10 15 20 25

Days After Glochidial Infestation

Number of Mussels

glochidia w/otissueglochidiaw/tissuejuveniles

ResultsFigure 3 - Number of Glochidia and Juveniles Produced

Over Time for Blackchin Shiner

0

2

4

6

8

10

12

14

0 5 10 15 20 25

Days After Glochidial Infestation

Number of Mussels

glochidia w/otissue

glochidia w/tissue

juveniles

ResultsFigure 4 - Number of Glochidia and Juveniles

Produced Over Time for Longnose Dace

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25

Days after Glochidial Infestation

Number of Mussels

glochidia w/otissueglochidia w/tissuejuveniles

ResultsFigure 5 - Number of Glochidia and Juveniles

Produced Over Time for the Mimic Shiner

0

1

2

3

4

5

6

7

8

9

0 5 10 15 20 25

Days After Glochidial Infestation

Number of Mussels

glochida w/otissueglochidiaw/tissuejuveniles

Conclusions

• Common shiner, mimic shiner, blackchin shiner and longnose dace are host fish

• Not able to determine difference between glochidia without tissue and with tissue

• It appears that related fish host the same mussel

Practical Applications

• Results of the statistically stronger host fish could be used to reintroduce the Round Pigtoe mussel by making raising mussels in a laboratory setting more efficient

• By finding that related fish host the same mussel, host suitability trials can be simplified

Future Studies

• Repeat the study with many species of fish from the same family

• Conduct a Histological study with pictures of mussels at different life cycle stages to deterimine if glochidia without and with tissue are separate life cyce stages

Acknowledgements

• Mark Hove

• Kari, Vik and Kaia

• Ms. Fruen

• Dr. Miller

Acknowledgements

Statistical Study of Host Fish for the Round Pigtoe Mussel (Plueurobema coccineum)

By Meggie Marzec

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

www.darbycreeks.org/Round%20pigtoe%20Big%20Darby%208-2-03%20005.jpg