]> http://projectwatershed.org/taxonomy/term/18/0 en http://projectwatershed.org/aquatic_worm <a href="aquatic_worm"><span class="image thumbnail"><img src="http://projectwatershed.org/uploads/projectwatershed_files/images/aquaticworms.jpeg" width="462" height="204" alt="Aquatic Worm" title="Aquatic Worm" /></span> </a><li > Moves by stretching and pulling its body along in a worm-like fashion </li> <li > May be red, tan, black or brown </li> <li > Can look like an earthworm or be much narrower and thread-like </li> <li > Segmented body </li> <li > Up to five inches long </li> <li > May have short bristles or hairs that help with movement, but are not usually visible </li> Pollution-Tolerant Tue, 2 May 2006 17:25:34 -0400 http://projectwatershed.org/blackfly_larva <a href="blackfly_larva"><span class="image thumbnail"><img src="http://projectwatershed.org/uploads/projectwatershed_files/images/blackflylarva.jpeg" width="400" height="438" alt="Black Fly Larva" title="Black Fly Larva" /></span> </a><li >Up to 1/3 inches long &bull; The head is usually black, but sometimes brown, tan or green </li> <li > One very tiny leg-like appendage directly under the head </li> <li > Attachment disks (small suckers) on the end of the abdomen </li> <li > The body is segmented </li> <li > Back end of the body widens and is bulbuous </li> <li > No legs </li> <li > Tiny gills by head filter food from water </li> Pollution-Tolerant Tue, 2 May 2006 17:23:41 -0400 http://projectwatershed.org/leeches <a href="leeches"><span class="image thumbnail"><img src="http://projectwatershed.org/uploads/projectwatershed_files/images/leeches.jpeg" width="214" height="435" alt="Leeches" title="Leeches" /></span> </a><li > Only a few are parasites on humans </li> <li > Leeches that attach to humans are not found in fast moving water or riffle areas </li> <li > Many are scavengers or feed on other invertebrates </li> <li > Suckers at both ends are used for attachment, feeding, and locomotion </li> <li > They swim gracefully and quickly in an up-and-down motion </li> <li > They move by attaching suckers from end to end </li> <li > Worm-like, segmented body</li> <li > Body is somewhat flat</li> Pollution-Tolerant Tue, 2 May 2006 17:20:21 -0400 http://projectwatershed.org/midge_larva <a href="midge_larva"><span class="image thumbnail"><img src="http://projectwatershed.org/uploads/projectwatershed_files/images/midgelarva.jpeg" width="335" height="422" alt="Midge Larva" title="Midge Larva" /></span> </a><li > Almost 2000 species in North America </li> <li > Are found in all but the most polluted aquatic conditions </li> <li > Presence in large numbers may indicate organic enrichment </li> <li > Up to 1/2 inches long </li> <li > One pair of tiny, fleshy legs below the head and one pair on the back end </li> <li > The back end sometimes has a tin pair of extensions that look like brushes </li> <li > A thin dark line (digestive tract) can be seen inside the body </li> <li > Distinct, often dark head </li> Pollution-Tolerant Tue, 2 May 2006 17:18:01 -0400 http://projectwatershed.org/pouch_snail <a href="pouch_snail"><span class="image thumbnail"><img src="http://projectwatershed.org/uploads/projectwatershed_files/images/pouchsnails.jpeg" width="281" height="435" alt="Pouch Snail" title="Pouch Snail" /></span> </a><li >They get oxygen directly from air trapped in their shell cavity and thus are less dependent on water quality </li> <li >Shell is made of calcium carbonate </li> <li > It&rsquo;s important that the snail is alive (someone is at home) before counting it in a survey </li> <li > Shell is spiral, coil or dome shaped </li> <li > Has no operculum (plate-like door) </li> <li > Shells usually open on the left side, which can be seen if you hold the shell with its tip pointing up and the opening facing you</li> Pollution-Tolerant Tue, 2 May 2006 17:14:25 -0400