quagga mussel
Dreissena bugensis Andrusov, 1897

Dreissena bugensis or Quagga mussels are filter feeders native to the drainage basins of both the Dneiper River in the Ukraine and the Caspian Sea. It usually has light and dark brown stripes in an alternating pattern. However D. bugensis can also be solid light or dark brown. D. bugensis are rarely more than 2 in. (5.1 cm) in length. There are two phenotypes of this mussel. One form has a high flat shell and usually attaches itself to objects and forms colonies of D. bugensis. The other form has a more elongated shell and often buries itself in the sediment, extending its syphon upward to capture particles of food.
Life Cycle
D. bugensis eggs hatch then go through planktonic larval stages for up to 4 weeks. Larvae are usually moved by water flow, but may be aided by cilia action. Once larvae are large enough they develop into their juvenile stage. At this point they settle to the bottom and search for a substrate to attach to by a cluster of threads called a byssus. A single reproductively mature female may produce as many as a million eggs per breeding season.
D. bugensis is replacing zebra mussels where their populations overlap. D. bugensis has spread throughout Eastern Europe and parts of North America. They can be found in the Great Lakes and the Mississippi and Ohio Rivers.
Control Efforts
Most of the research done on controlling mussels has been focused on Dreissena polymorpha. However many of the control methods used for D. polymorpha should also work well for D. bugensis. Preventing infestations of D. bugensis by proper ballast water management including mid-ocean exchange and disinfection should be always be used. Physical removal by high pressure washes should be effective. Freezing, heating to high temperatures and desiccation should also control D. bugensis.