Video Spotlights

Barnacles grow on pilings, boats, rocks, and even other animals. They have hard outer plates that, once submersed, open to reveal featherlike legs called cirri, that whisk plankton from the water column into an internal cavity. This very short video shows the barnacle feeding.

Attached to rocks and other surfaces by fine fibers called byssal threads, hooked mussels open their shells during high tide to draw in water and filter out food particles over their gills. The hooked mussel grows prolifically on oyster reefs, often outnumbering the oysters themselves by several fold. Although the filtration capacity of the hooked mussel has not been calculated directly, the combined filter power of the oyster and hooked mussel together can be quite significant. This video shows the hooked mussel feeding and mud worms that live nearby.

Often mistaken for the invasive zebra mussel, dark false mussels are native to the Chesapeake Bay. In the summer of 2004, a population explosion of dark false mussels in the Magothy, Severn and South rivers on the Bay's western shore cleared local waters with its filtering power. The mussel attached itself to pilings, boats, cages, ropes, and every other hard surface it encountered. This video chronicles a large-scale community science initiative, led by Richard Carey of the Magothy River Association, to survey the size of populations in 2004 and to calculate how much water they could filter.

One of only a few true filter-feeding worms in the Bay, the parchment worm feeds on suspended organic material. The video shows the parchment worm in the laboratory, outside the tube that it creates to live in, so we can see its anatomy and feeding structures. Winglike notopodia pump sea water through its tube and the notopodia secrete mucus that is drawn back, forming a bag. The mucus bag filters the water to retain finer particles. Periodically, the particles are transported back to the mouth by the dorsal ciliated groove and ingested.

Still the go-to filter feeder in the Bay, this native oyster can process water at rates 2-3 times that of other bivalves. Beating cilia draw water over the gills where plankton and other particles are trapped in mucus and sent to the mouth. Follow the link to see this video on YouTube, from the Chesapeake Bay Foundation, which shows time-lapse photography of the capacity of oysters to clear the water.