Wednesday, August 01, 2007

Freshwater mussels, catbird and buttonbush

August 1st, 90 degrees and very dry. I saw a catbird, it came very close to me, unusual since they are very shy. Lots of goldfinches feeding on the sunflowers, I wish I had a camera fast enough to get a photo of that! The kingfisher has stayed nearby all summer.

The Portage is very low, and I went wading down the river. This is Cephalanthus occidentalis, buttonbush, with it's orange-y (not brown) pods, hanging over the river.

Usually I see the freshwater mussels laying on shore, popped open and eaten by some animal. The presence of them usually means that the water is clean, but I still don't think I would eat one. Today I found some shells in the river. People here just generically call them "freshwater clams", but it turns out there are many different kinds. Many that I have seen here are very large, maybe eight inches or more long. This one is about four or five inches. I don't know what it is/was. They were all eaten in the past by humans, back when rivers and lakes were unpolluted; since they are so hard to tell apart, the existence of all those common names probably means they had some economic importance at some time, otherwise why would people in the old days name them?

Clams and mussels are much under attack from pollution and by invasive zebra mussels as well as loss of habitat and hosts.

Here is an alphabetic list of "freshwater clams" found in the St. Joseph drainage, therefore most likely in the Portage River too. The links to photos open in a a new window; web standards say that opening new windows frightens people, so beware.

Actinonaias ligamentina ("Mucket", previously Actinonaias carinata)

Alasmidonta viridis ("Slippershell", also called Alasmidonta calceolus)

Alasmidonta marginata ("Elktoe")

Amblema plicata ("Three-ridge")

Anodontoides ferussacianus ("Cylindrical papershell")

Cyclonaias tuberculata ("Purple wartyback")

Elliptio dilatata ("Spike")

Epioblasma triquetra ("Snuffbox", Michigan State listed as endangered)

Fusconaia flava ("Wabash pigtoe")

Lampsilis siliquoidea ("Fat mucket")

Lampsilis ventricosa ("Pocketbook")

Lasmigona compressa ("Creek heelsplitter")

Lasmigona costata ("Fluted shell")

Leptodea fragilis ("Fragile papershell")

Ligumia recta ("Black sandshell")

Pleurobema coccineum ("Round pigtoe")

Potamilis alatus ("Pink heelsplitter", previously Proptera alata)

Pyganodon grandis ("Giant Floater" - what's that mean?)

Strophitus undulatus ("Creeper")

Truncilla donaciformis ("Fawnsfoot")

Truncilla truncata ("Deertoe")

Venustaconcha ellipsiformis ("Ellipse")

Villosa iris ("Rainbow")