Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 18 results
Media
Photo of a pink planarian on a rock.
Species Types
Scientific Name
Dugesia, Planaria, and other genera
Description
Unlike their parasitic cousins in the flatworm group, turbellarians, or planarians, are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects.
Media
Photo of a belted crayfish, also called Big River crayfish.
Species Types
Scientific Name
Faxonius harrisonii (formerly Orconectes harrisonii)
Description
The belted crayfish is medium-small, tan, with a distinctive pattern of alternating olive-green and reddish-brown bands on the abdominal segments. It is found only in the Big River and its tributaries.
Media
Photo of a ringed crayfish.
Species Types
Scientific Name
Faxonius neglectus (formerly Orconectes neglectus)
Description
The ringed crayfish is olive green to reddish tan and usually has black or brown rings around the pincer tips. In Missouri it is found in clear, rocky Ozark streams in the southwestern quarter.
Media
Photo of a golden crayfish viewed through the surface of creek water.
Species Types
Scientific Name
Faxonius luteus (formerly Orconectes luteus)
Description
The golden crayfish varies in color from olive green to golden yellow. Many body parts are trimmed with red. A dark band crosses the head just in front of the cervical groove, and another crosses the carapace at its junction with the abdomen. It's a wide-ranging species.
Media
Photo of a spothanded crayfish viewed through creekwater.
Species Types
Scientific Name
Faxonius punctimanus (formerly Orconectes punctimanus)
Description
The spothanded crayfish is moderately large and usually has a noticeable black spot on each pincer near the base of the movable finger. In Missouri, it is found mostly in Ozark waterways in the southeastern quarter of the state, from Callaway, Montgomery, and Warren counties south.
Media
giant floater
Species Types
Scientific Name
Pygandon grandis
Description
When a floater dies, this large mussel with a thick shell will actually rise to the water surface and float as it decays.
Media
lilliput
Species Types
Scientific Name
Toxolasma parvus
Description
These diminutive mollusks are the smallest of Missouri’s freshwater mussels.
Media
pistolgrip
Species Types
Scientific Name
Tritogonia verrucosa
Description
Shaped like a checkered gunstock, with its unique, turned-down edge, pistolgrips are easy to identify.
Media
pond mussel
Species Types
Scientific Name
Ligumia subrostrata
Description
This widespread species is one of the few Missouri mussels successful in shallow ponds and lakes.
Media
spike
Species Types
Scientific Name
Elliptio dilatata
Description
Nacre color varies from purple to pink to white. In smaller rivers, the shell is much thinner.
See Also

About Aquatic Invertebrates in Missouri

Missouri's streams, lakes, and other aquatic habitats hold thousands of kinds of invertebrates — worms, freshwater mussels, snails, crayfish, insects, and other animals without backbones. These creatures are vital links in the aquatic food chain, and their presence and numbers tell us a lot about water quality.