Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 22 results
Media
Photo of a woodland crayfish.
Species Types
Scientific Name
Faxonius hylas (formerly Orconectes hylas)
Description
The woodland crayfish is stout, reddish tan to dark brown, with numerous blackish specks and blotches on the pincers, carapace, and abdomen. It occurs only in Missouri, especially in the Black River and its tributaries.
Media
Photo of an Ozark crayfish.
Species Types
Scientific Name
Faxonius ozarkae (formerly Orconectes ozarkae)
Description
The Ozark crayfish is light brown to reddish brown with numerous black specks on the pincers and often on the abdomen as well. The pincers are broad and powerful. It lives in the White and Black stream systems.
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 saddleback crayfish.
Species Types
Scientific Name
Faxonius medius (formerly Orconectes medius)
Description
The saddleback crayfish has a bold blackish band across the hind margin of the carapace and lacks dark blotches or specks. The pincers are broad and powerful. It occurs in the Big and Meramec river drainages.
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 northern, also called virile, crayfish.
Species Types
Scientific Name
Faxonius virilis (formerly Oronectes virilis)
Description
The virile crayfish is large, reddish brown or green, and lacks prominent markings. The pincers are green with orange tips and are studded with whitish knobs. Paired dark blotches run along the abdomen. This species is widespread.
Media
Photo of a Shufeldt’s dwarf crayfish.
Species Types
Scientific Name
Cambarellus shufeldtii
Description
Shufeldt’s dwarf crayfish is small, reddish brown to gray, with a paired series of dark, wavy stripes or dashes along the dorsal surface. In Missouri, it occurs in our southeastern lowlands and north along the Mississippi River floodplain.
Media
Photo of a shrimp crayfish.
Species Types
Scientific Name
Faxonius lancifer (formerly Orconectes lancifer)
Description
The shrimp crayfish is medium-small, light reddish brown to gray, and thickly dusted with darker specks. Its noselike rostrum is unusually long, with the tip longer than the base, and the pincers are narrow and weak. It is found in the Bootheel.
Media
Photo of a Cajun dwarf crayfish.
Species Types
Scientific Name
Cambarellus puer
Description
The Cajun dwarf crayfish is small, reddish brown to gray, with a paired series of dark, wavy stripes or dashes along the dorsal surface. In Missouri, it occurs in our southeastern lowlands.
Media
ellipse
Species Types
Scientific Name
Venustaconcha ellipsiformis and V. pleasii
Description
These small mussels use darters, a type of fish, as hosts for their young.
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.