| Background:
Fresh-water mussels (also called clams) are related to oysters, snails, squid, and the octopus. All these animals belong to the group of animals called "mollusks" and most secrete a protective shell around themselves. Examination of the shells one might find at the seashore or on a riverbank reveals that the shells can be grouped into two types, those that form matching mirror-image pairs,joined by a hinge, and those that are a single structure. Clams, oysters, and mussels produce the hinged shells, which occur in a variety of sizes, shapes, colors and surface textures. Some of the mussel types found in Tennessee were given names such as "Shiny Pigtoes", "Little Wings", and White Warty-backs" to describe their unusual appearance!
The species of Tennessee mussels that are decling or are on the federal or state lists of endangered species are:
| Birdwing pearly mussel |
Fanshell mussel |
| Dromedary pearly mussel |
Yellow-blossom pearly mussel |
| Upland combshell |
Southern acornshell |
| Green-blossom pearly mussel |
Tubercled-blossom pearly mussel |
| Turgid-blossom pearly mussel |
Tan riffle shell pearly mussel |
| Purple cat's paw pearly mussel |
Fine-rayed pigtoe pearly mussel |
| Shiny pigtoe pearly mussel |
Cracking pearly mussel |
| Pink mucket pearly mussel |
Alabama lamp pearly mussel |
| Alabama moccasinshell |
Coosa moccasinshell |
| Ring pink mussel |
Little-wing pearly mussel |
| White warty-back pearly mussel |
Orange-footed pearly mussel |
| Southern clubshell |
Southern pigtoe |
| Cumberland pigtoe mussel |
ovate clubshell |
| Rough pigtoe pearly mussel |
Triangular kidneywhell |
| Cumberland monkeyface pearly mussel |
Winged mapleleaf mussel |
| Appalachian monkeyface pearly mussel |
Pale lilliput pearly mussel |
| Cumberland bean pearly mussel |
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References:
Fresh-Water Invertebrates of the United States by Robert W. Pennak (1953)
Invertebrate Zoology by Robert D. Barnes (1963)
America's Pearly Mussels (video and poster), available for $6 plus shipping from Virginia Tech, 112 Landowne St, Blacksburg, VA 24061, ATTN: Richard neves, (703) 231-5927.
Freshwater Mussels of Tennessee by Paul W. Parmalee and Arthur E Bogan, 1998
Focus:
Many species of freshwater clams ("mussels") in Tennessee are declining due to human activities.
Procedure:
- Do this activity after you have introduced students to the life cycle of freshwter mussels. (Use the video listed under References.)
- Pass out the Missing Mussels Worksheet
- Considering the required habitat conditions, students are to brainstorm how the described human activities could change the habitat and how the change would affect the survival of mussels.
- Point out that these are not the only threats to the survival of mussels. Over-harvesting has been a problem in the past. past creation of reservoirs flooded prime mussel habitat. Also the non native Asian and Zebra mussels that are appearing in Tennessee rivers may out-compete the native mussels for suspended food particles and may attach to the shells of native mussels, interfering with their siphoning of water.
- Have students study the bar graph to identify the locations at which there may be pollution problems (near mile 46 and mile 70). Have the speculate as to what the problems may be.
- Lead students to conclude that good quality mussel habitat should be protected and that efforts to restore degraded habitat are worthwhile.
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