Oligochaete worms are common in fresh waters, but they are often ignored by freshwater biologists because they are generally thought to be extraordinarily difficult to identify. While some species can be difficult to separate, most genera and some species have distinctive features that can be seen with a good compound microscope. To aid the beginner in the identification of this important invertebrate group, Pascal Sweeney, in conjunction with the National Biodiversity Data Centre, has devised an introductory on-line key to the oligochaetes found in Irish freshwaters. Follow the link to this key on the NBDC website:  http://apps.biodiversityireland.ie/OligochaeteIdKey/index.php
While this key has been tested by several biologists, there is likely to be room for improvement and therefore comments by anyone who uses the key would be welcomed. Comments can be emailed to: pascalsweeney@eircom.net