Order Decapoda (crayfish)
Key features
5 pairs of legs
2 claws
1/2-5" long.
Crayfish are quite easy to identify. They closely resemble a small lobster. They can be found under loose rocks in the middle or along the edges of the River. They will
swim swiftly backwards if frightened or disturbed. Crayfish are pollution intermediate organisms and are common throughout all stretches of the River. They feed primarily on dead plant
material, live snails and other macroinvertebrates.
 | Family: Cambaridae
Genus: Oronectes
|
Order: Amphipoda (scuds)
Key features:
"shrimp-like"
usually quite small, 1/8-1/4" long
Scuds look basically like little shrimp and are actually closely related. They have a swimming motionsimilar to that of crayfish, propelling themselves backwards
through the water with quick strokes of their tails. They may be slightly orange or green and are somewhat translucent and shiny. Scuds are pollution intermediate organisms that are rarely found
in the River. They are general scavengers and tend to hide under stones in shallow areas.
 | Order: Amphipoda
Family: Crangonyctidae
Genus: Crangonyx |
Order: Isopoda (sowbugs)
Key features:
segmented, flat body with many legs
1/4-1/2" long
Sowbugs are gray and segmented, with an "armored" appearance. They look very similar to terrestrial pill bugs. They have a sort of rectangular shape and
many small legs. Sowbugs are pollution intermediate organisms that are common throughout all but the very upper reaches of the River. They are scavengers on dead animal and plant material and
tend to remain under stones or in debris.
 | Order: Isopoda
Family: Asellidae
Genus: Caecidotea (side view) |
 | Order: Isopoda
Family: Asellidae
Genus: Caecidotea (top view) |
