FRESHWATER MUSSELS. Master Naturalist Program September 27, 2016

Transcription

1 FRESHWATER MUSSELS Master Naturalist Program September 27, 2016 Alison Stodola Aquatic Field Biologist Illinois Natural History Survey Prairie Research Institute - University of Illinois alprice@illinois.edu Intro to freshwater mussels Diverse taxonomy Benthic, long-lived Ecologically important Parasitic life stage Imperiled 1

2 North America has richest diversity Nearctic: 367 spp. Neotropical: 96 spp. Palearctic: 24 spp. Ethiopian: 74 spp. Oriental: 183 spp. Australasian: 28 spp. Freshwater mussels presently occur on all continents except Antarctica. 80+ species known from IL Mussels in your backyard (species alive post-1980) 2

3 Culturally important Benthic organisms (live on the bottom) 3

4 They are nature s water filter Excreting nutrients Deposition of materials Bioturbation of sediments mussel siphons 1 adult mussel filters ~1 liter per hour (roughly 6 gallons per day) 100 mussels filter ~26 gallons per hour (650 gallons per day) mussel bed 4

5 Ecologically important river otter muskrat Food for mammals, fish, and birds Ecologically important madtom darter eggs Shelter and nest material for fish & crayfish 5

6 Parasitic life stage fish gills young mussel glochidia (larval mussels) adult mussel Cummings and Graf (2009) Marsupial gills of Lampsilis M. C. Barnhart 6

7 Brooding nature of mussels marsupium Eastern lampmussel (eastern USA) Brooding nature of mussels Eastern lampmussel (eastern USA) 7

8 Conglutinates! Glochidia on gills 8

9 Glochidia encysted Wabash Pigtoe Fusconaia flava Rock Pocketbook Arcidens confragosus Pink papershell Potamilus alatus Plain pocketbook Lampsilis cardium M. C. Barnhart 9

10 Juvenile mussels! M. C. Barnhart Juveniles from Embarras River 10

11 Mussels are imperiled Of 300 species in North America: ENDANGERED AT RISK EXTINCT STABLE Mussels in Illinois Stable? Extinct or extirpated Fed listed Historically, over 80 species known Currently, Illinois has 61 State listed Conservation Need 11

12 Reasons for the decline of freshwater mussels Siltation Channelization Dams Land use practices Chemical pollution Mining Hydrology Exotics Historic harvest Reasons for the decline of freshwater mussels siltation / sedimentation 12

13 Reasons for the decline of freshwater mussels channelization Kankakee River Indiana-Illinois state line Reasons for the decline of freshwater mussels dams 13

14 Reasons for the decline of freshwater mussels Livestock / land-use Reasons for the decline of freshwater mussels Chemical pollution 14

15 Reasons for the decline of freshwater mussels Mining Reasons for the decline of freshwater mussels Hydrology 15

16 Reasons for the decline of freshwater mussels Exotics Asian clams Zebra mussels Reasons for the decline of freshwater mussels Historic harvest 16

17 Pearl button industry ( ) Pearl button industry ( ) 17

18 Pearl button industry ( ) Cultured pearl industry ( now) 18

19 Cultured pearl industry ( now) Cultured pearl industry ( now) Freshwater mussel shell Shells cut and tumbled into nuclei Inserted with oyster tissue into triangle shell mussel (Hyriopsis cumingii) 19

20 Cultured pearl industry ( now) Farm in ocean Harvested pearls Shell nuclei Now for some good news Re-introduction efforts of federally endangered mussels, northern riffleshell and clubshell 20

21 Now for some good news Re-introduction efforts of federally endangered mussels, northern riffleshell and clubshell Illinois River recovery Scaleshell (Leptodea leptodon) rediscovered in Illinois River. Last found in Illinois in 1912! 21

22 Shell anatomy M. C. Barnhart Diagram adapted from Pierce and Pierce 1987, Living Invertebrates.

23 Body anatomy M. C. Barnhart Diagram adapted from Pierce and Pierce 1987, Living Invertebrates. M. C. Barnhart Diagram adapted from Pierce and Pierce 1987, Living Invertebrates.