Aquatic Worm

Limnodrilus hoffmeisteri

Limnodrilus hoffmeisteri is one of many species of aquatic worms, also called "oligochaetes." Aquatic worms are close relatives of earthworms, but they live in water instead of the ground. Aquatic worms can be found anywhere there is fresh water, including lakes, ponds, marshes, and streams. They prefer shallow water.

Limnodrilus hoffmeisteri grows up to five centimeters long, and its body is about one millimeter wide. They have reddish bodies, which are split into segments. Just like earthworms, the ends of their bodies are pointed; but the body wall of these worms is so thin, you can see through it to the animal's organs. Though you might not normally notice them, these aquatic worms are probably the most common animal in the water!

Cluster of Limnodrilus hoffmeisteri

Environmental Cleanup & Restoration: CASE STUDY Foundry Cove in the Hudson River, New York

Aquatic worms crawl around on top of, or inside, the mud at the bottom. They eat the mud and any small bits of plant or animal matter they find. This worm often arranges itself head downward by building a small tube in the mud and letting its butt stick out into the water. Many aquatic worms can be found together; and their bodies, sticking out of their tubes, wave back and forth with the currents of the water.

Aquatic worms, like Limnodrilus hoffmeisteri, are "bioturbators." This means they move the soil. As the worm eats mud with its head down below, the dirt comes out the back end of the worm. This soil-moving is very important to keep the stream or lake healthy. Aquatic worms also break down pollutants which settle to the bottom and poison the water.

Aquatic worms, just like earthworms, are hermaphrodites. This means there's not really a male or female. When aquatic worms mate, each worm is then able to lay eggs. Aquatic worms lay eggs inside small cocoons in the mud, on rocks, or on plants. Eggs are usually laid in late Summer or early Fall.

Juvenile aquatic worm from the Tubificidae Family Tom Bird, Biologica Environmental Services Ltd.

Aquatic worms have many predators. They are a favorite food for young fish, aquatic insects, leeches, and crayfish. They are also eaten by tadpoles, turtles, and ducks. These worms coil up when they feel threatened.

Aquatic worms breathe through their body walls. They can also regenerate, or grow back, body segments which are damaged or lost.

Worms and cocoons are often transported to new places when the mud they are in sticks to birds' feet. Wading birds, like herons and egrets, drop them off in a new lake or stream. Because of this, many species, such as Limnodrilus hoffmeisteri, are found worldwide.

Aquatic worms usually live one to two years.  

Additional Media

Description
Type
Credit
Aquatic Worm Bioturbating
Video (Long download, approx 3 minutes on T1)
Mark Moran
Three Aquatic Worms Bioturbating (side view)
Video (Long download, approx 3 minutes on T1)
Mark Moran
Four Aquatic Worms Bioturbating (top view) #1
Video (Long download, approx 3 minutes on T1)
Mark Moran
Four Aquatic Worms Bioturbating (top view) #2
Video (Long download, approx 3 minutes on T1)
Mark Moran
Four Aquatic Worms Bioturbating (top view) #3

Video (Long download, approx 3 minutes on T1)

Mark Moran

Video (Long download, approx 3 minutes on T1)
Mark Moran
Aquatic Worms Interacting
Video (Long download, approx 3 minutes on T1)
Mark Moran
Aquatic Worms Hiding, Then Re-emerging
Video (Long download, approx 3 minutes on T1)
Mark Moran
Aquatic Worms Harassed by Copepod
Video (Long download, approx 3 minutes on T1)
Mark Moran

Relationships in Nature:

FOOD
PREDATORS
SHELTER
OTHER

Golden Shiner

Common Duckweed

The Big Red Worm Pa

Eastern Mosquitofish

Hydrilla

Creek Chub

Lizard's Tail

Tesselated Darter

Greater Bladderwort

Yellow Perch

Long-leaf Pondweed

Channel Catfish

Pickerelweed

Bluegill

Largemouth Bass

Yellow Bullhead

Black Crappie

Northern Caddis Fly

Green Darner

Ebony Jewelwing

Eastern Dobsonfly

Large Diving Beetle

Mallard

Eastern Painted Turtle

Common Snapping Turtle

Bullfrog

Three-lined Salamander

Relationship to Humans:

Aquatic worms are an important food source for most young fish, many of which we eat when they grow bigger. Aquatic worms also help break down pollutants in the mud at the bottom of lakes, marshes, and streams. Aquatic worms sometimes are hosts for dangerous parasites, such as The Big Red Worm.

KINGDOM
Animal
PHYLUM
Annelid
CLASS
Oligochaeta
ORDER
Tubificida
FAMILY
Tubificidae
GENUS
Limnodrilus
SPECIES
Limnodrilus hoffmeisteri
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