Gammarus from Saginaw Bay, Lake Huron. Microphotograph taken by G. Carter, April 2000.

Hyalella from Saginaw Bay. Microphotograph taken by Glenn Carter, April 2000.

Zebra mussels (Dreissena polymorpha) attached to native clam (unionid) Lampsilis.

Oligochaete worm. Microphotograph taken by Glenn Carter, April 2000.

Microphotograph of typical benthic animals. Microphotograph taken by G. Carter, April 2000.

Healthy calanoid copepod (Diaptomus spp.). Summer 2000.

Quagga mussels in Lake Michigan sediment sample from Lake Michigan taken during whole lake benthic survey, June 2005.

Cercopagis (upper) and Bythotrephes. Invading predatory cercopagids that have invaded the Great Lakes in ballast water. Bythotrephes invaded Lake Michigan in 1986. Cercopagis invaded lake Ontario and Lake Michigan in 1999. Arrows point to the thoracopods (feeding appendages). Microphotograph taken by J. Liebig, NOAA GLERL, 2001.

Dikerogammarus villosus. Photo by S. Giesen (1998).

Echinogammarus, male. Microphotograph taken by G. Carter, 2001.

Quagga mussels (top row) and zebra mussels (bottom row).

Female and male cyclops bicuspidatus. Dominant cyclopoid species in Lake Michigan. Microphotograph by J. Liebig, NOAA GLERL, 2000.

Adult copepods from Lake Michigan. Microphotograph by J. Liebig, NOAA GLERL, 2000.

Resting egg pouch (ephippium) and the juvenile Daphnid that just hatched from it. Collected from residual sediment of a NOBOB ballast tank in 2001. Photo by S. Bandoni and H. MacIsaac.

Harpacticoid copepod found in the residual water of a NOBOB ballast tank in 2001. Photo by H. Limen and H. MacIsaac.