Giant Floater
Pyganodon grandis
Mussel Description 2
Pyganodon grandis (giant floater) is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species is fast-growing, large, and has a short lifespan.
Tan to dark brown in color. Shell is very thin. No teeth. Highly iridescent nacre. Can grow to a very large size (~10 inches). ** Beaks somewhat prominent and sculptured with 2-3 nodulous doublelooped bar.*
(Source: Freshwater Mussels of the Upper Mississippi).
*(Source: A Field Guide to the Freshwater Mussels of the Chicago Wilderness).
Visually Similar Species in the Milwaukee River Basin 3
Creeper and Cylindrical Papershell.** Other species can be confused with the Giant Floater, though they have not been commonly found in the Milwaukee River Basin.
The cylindrical papershell is more elongated and smaller than the giant floater.**
The giant floater has a more inflated shell and a straight hinge line compared to the creeper. **
**(Source: A Field Guide to the Freshwater Mussels of the Chicago Wilderness).
Status in Milwaukee River Basin 3
Milwaukee Riverkeeper has found both live Giant Floaters and valves commonly in the South Branch of the Milwaukee River and the Cedar Creek Watersheds. They have typically been found on the main branches of these rivers.
Sources and Credits
- (c) Zac Driscoll, all rights reserved, uploaded by Zac Driscoll
- Adapted by Zac Driscoll from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Pyganodon_grandis
- (c) Zac Driscoll, some rights reserved (CC BY-SA)
