Content tagged with "Aquatic Invertebrates"

Spike (Ladyfinger)

Elliptio dilatata
Nacre color varies from purple to pink to white. In smaller rivers, the shell is much thinner. More

Spothanded Crayfish

Image of a spothanded crayfish
Orconectes punctimanus
This moderately large crayfish has a conspicuous 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. More

Spotted Fishing Spider

Image of a fishing spider
Dolomedes triton
These long-legged, dark-colored water spiders are distinctive in that the oval abdomen is smaller than the broad cephalothorax. The rim stripe surrounding the dark carapace, and sometimes the abdomen, is whitish-yellow. On top of the dark brown abdomen, three distinctive pairs of minute white spots create a connect-the-dot pattern or run mid-line down the back. The brown legs are robust and dotted with white hairs. More

St. Francis River Crayfish

Image of a st. francis river crayfish
Orconectes quadruncus
This crayfish is limited to the St. Francis River and its tributaries. It's a rather small, dark brown species, with blackish blotches or specks over the upper surfaces of the pincers, carapace and abdomen. More


Photo of an adult stonefly on a leaf
There are hundreds of species in North America
Stoneflies have a lot in common with mayflies, caddisflies, dragonflies and dobsonflies: They begin life as aquatic larvae, then molt and become winged adults. Many fish find stoneflies irresistible, and anglers take advantage of it! More

Threehorn Wartyback

threehorn wartyback
Obliquaria reflexa
Among all the mussels of Missouri, this is perhaps the easiest to recognize: As the shell grows, large knobs are produced, first on one shell and then on the other, in an alternating pattern. More


Amblema plicata
Sometimes called the blue-point, this mussel species is widely distributed in Missouri rivers and is occasionally found along reservoir margins. More

Turbellarians (Planarians; Free-Living Flatworms)

Photo of a pink planarian on a rock.
Various species in various genera (Dugesia, Planaria, etc.)
Turbellarians become the favorites of almost everyone who has taken the time to observe them. Unlike their parasitic cousins in the flatworm group, turbellarians are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects. More

Vernal Crayfish

Image of a vernal crayfish
Procambarus viaeviridus
In our state, this crayfish is found only in the southeastern swamps, and then usually only seen in February and March. Adults are rust-red with a blackish wedge-shaped central stripe along the length of the abdomen. More

Virile Crayfish

Image of a virile crayfish
Oronectes virilis
This widespread, large crayfish is reddish-brown or green, without prominent markings. The pincers are green with orange tips and in adults are conspicuously studded with whitish knobs. Paired dark blotches run lengthwise along the abdomen. More