Key to common benthic macroinvertebrates of watercourses.

3a) Soft-bodied organism without jointed legs or antenna. Body either flat or worm-like, with or
without segmentation. If segmented, then more than 13 segments evident. 4

3b) Organism with jointed legs, leg-like appendages (prolegs), or antenna. Body segmented. If animal
without legs, then body is caterpillar-like with fewer than 14 segments. Arthropods -- 7




Return to Couplet 1
Return to BioMAP Central