Oligochaeta (Aquatic Earthworms)
- Soft-bodied, many-segmented, and elongate.
- No distinct head region.
- May have bristles, hairs, or gills when viewed under the microscope.
- Beige to red when alive.
- Often curl into a "curlicue" when preserved in alcohol.
Length: 5 mm to 40 mm
Peter Chen.