Umbos - Comparison

Comparing the height and convexity of the umbo is important in dreissenid identification. Two forms are recognized, as follows:

1. Umbos are equal in height as in Dreissena polymorpha.
2. Umbos are slightly higher or more convex in shape.

    

   Cases where the umbos are unequal in height are usually very difficult to observe using standard light microscopy.

    

   

    

   Larval Identification Information

   Zebra Mussel Identification