Aquatic Caves

Cave Spring

Caves with creeks, groundwater, or springs are known as aquatic or wet caves. Many rare and vulnerable animals call these dark, wet tunnels home.

Wet Cave Diversity

Though there is a lot of overlap, wet cave communities can be described based on the way water flows within them.

Cave Springs

A cave spring is a cave that has a stream flowing from the entrance. This water flow is often permanent or nearly permanent. Cave springs are usually positioned at the base of steep slopes or bluffs along streams. The water's source is usually rainwater, which flows into the cave through sinkholes or through the permeable rocks (limestone, dolomite) above. Usually, the passages branch into the cave like tree branches. The networks of passageways can total more than 26 miles in length.

Most of our major bat caves are cave springs, which are sometimes called effluent caves. The ecosystem in these caves usually begins with the nutrients in bat guano. Bats eat insects outside the cave, then fly into the cave to roost. The guano that collects below them is broken down and digested by microorganisms and tiny animals, which then are eaten by increasingly larger animals.

Swallets

Swallets, sometimes called swallet holes or influent caves, can have an intermittent or perennial flow of water, but in this case the water, usually a stream, enters the cave system through a “swallow hole.” The swallow hole can be a horizontal entrance, a sinkhole, or a crack in a stream. A “pirated stream” is when a surface stream is “pirated” as it is diverted underground via a sinkhole or cave within its valley. Passageways of influent caves are relatively simple and can be hundreds of feet to several miles long.

The ecosystem of influent caves tends to have more nutrients fed into it than effluent caves do. Large amounts of organic material (eroded soil, branches, leaves) can be flushed into the cave by rainwater, surface streams, flooding, and other runoff.

Wet Pit Caves

Pit caves have vertical cave entrances, which are called shafts or pits. These shafts can be several feet to more than 100 feet deep. These entrances are often associated with sinkholes or crevices on bluffs. As the name suggests, wet pit caves have permanent water in the form of underground streams or lakes.

Nutrients enter the cave in the form of organic materials (anything living or once living) that fall into the cave. These caves are rare. Bats are not usually associated with them.

Missouri has more than 7,000 caves identified (so far). If their tunnels were all combined and straightened out, they would run for more than 500 miles. Most of our wet caves are in the Ozark Highlands ecoregion (Ozark and Ozark Border natural divisions), where they occur in soluble dolomite or limestone. There are almost no caves in northwestern Missouri and in the Bootheel lowlands.

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 several prosobranch pond snails crawling on a rock.
Species Types
Scientific Name
Over 20 Missouri species in former subclass Prosobranchia
Description
Gilled snails are one of two main groups of aquatic snails in Missouri (the other group is the "lunged" snails). Gilled snails, or prosobranchs, breathe with gills and possess a hard trapdoor-like operculum. They are most common in the Ozarks.
Media
Photo of amphipod on a rock
Species Types
Scientific Name
Species in the crustacean order Amphipoda
Description
Often overlooked by people, but eagerly sought by fish, Missouri’s amphipods resemble shrimplike sowbugs. Scuds live in various aquatic habitats, and several species inhabit caves.
Media
Photo of an aquatic isopod in an aquarium, crawling on a rock.
Species Types
Scientific Name
Freshwater members of the crustacean order Isopoda
Description
Everyone knows about terrestrial sowbugs and pillbugs, but many isopod species are aquatic. Missouri has several isopods that live in streams, ponds, rivers, and caves.
Media
Photo of a spothanded crayfish viewed from above on white background.
Species Types
Scientific Name
About 36 species in Missouri
Description
Crayfish are freshwater aquatic invertebrates that look a lot like small lobsters, to which they are related. There are about 36 species of crayfish in Missouri.
Media
Grotto sculpin side view photo with black background
Species Types
Scientific Name
Cottus specus
Description
The grotto sculpin is a rare fish adapted cave conditions. It has recently been designated an endangered species under the Federal Endangered Species Act. It's found only in Perry County, Missouri.
Media
Ozark cavefish side view photo with black background
Species Types
Scientific Name
Amblyopsis rosae
Description
The Ozark cavefish is small, colorless, and blind. It lives only in springs, cave streams, and underground waters. It has been declared Endangered in our state and as Threatened by the U.S. Fish and Wildlife Service.
Media
Southern cavefish side view photo with black background
Species Types
Scientific Name
Typhlichthys subterraneus
Description
The southern cavefish has a long, flattened head without eyes. It is whitish-pink because it lacks pigmentation. The only other Missouri fish that lacks eyes is the Ozark cavefish.
Media
Image of a cave salamander
Species Types
Scientific Name
Eurycea lucifuga
Description
The cave salamander is a common amphibian of the Ozark Plateau. It lives in caves, springs, and rocky streams. Recognize it by its normally bright orange skin dotted with dark brown or black spots.
Media
Image of a grotto salamander
Species Types
Scientific Name
Eurycea spelaea
Description
Many people know Missouri as “the cave state,” and the grotto salamander is Missouri’s only species of blind salamander. A true troglobite, it lives in total darkness and has small eyes that are completely or partially covered by their pink or beige skin.
Media
Silver-haired bat in flight.
Species Types
Scientific Name
About 14 species in Missouri
Description
Bats are the only mammals capable of sustained flight. At least 14 species of bats occur in Missouri; they are all relatively small, and they eat insects. Many of them are declining.
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