Phylum Tardigrada (Waterbears / Moss Piglets) in the Christopher B. Smith Preserve

Tardigrade Characteristics: All tardigrades are considered aquatic because they must be surrounded by at least a film of moisture in order to be active, however they can remain alive in a dormant state if the habitat dries out. Tardigrades can survive extreme environments: temperatures of -200˚ to +150˚, and extremely high and low pressures. They survive by going into a survival state in which a protective sugar moves into the cells and replaces lost water. Tardigrades can survive without food or water for more than 10 years, and then rehydrate, eat, and reproduce. Without dormant periods, they normally live 3 to 30 months.

They are tiny animals that are short, plump, cylindrical, and bilaterally symmetrical. The body is segmented. The five segments include a head, three body segments each with a pair of legs, and a caudal segment with a pair of legs that point posteriorly. The head usually has a pair of small eyespots. The mouth consists of a sucking tube and a pair of stylets that are dagger-like. The pharynx is a muscular bulb. Each of its 8 legs has four or more hooked claws. Tardigrada means "slow stepper," however when this animal is in a moist environment it can move fairly quickly by pulling itself along over the substrate by its claws.

In size, tardigrades are .5 mm to 1.2 mm when fully grown. They reproduce both asexually and sexually.

There are more than 900 identified tardigrade species. Classification is often determined by the shapes of the claws. Tardigrades live in almost every habitat on Earth. Terrestrial forms live in a film of water on lichens and mosses, in sand dunes, soil, sediments, and leaf litter.

Interactions in the Smith Preserve: Tardigrades feed on fluids of plant cells, bacteria, algae, and small invertebrates. They are preyed upon by nematodes, other tardigrades, mites, spiders, insect larvae, parasitic porotzoa, and fungi.

 

Unknown Species ... Water Bear On March 4, 2015, leaf litter was removed from under a Quercus geminata (Sand Live Oak) tree in sand scrub area in the middle of the Smith Preserve. The .4 mm individual shown here was removed from the litter with a Berlese Funnel. The photographs were created using photomicroscopy. On March 18, 2015, this animal was identified as a tardigrade by Ken Wolgemuth, Contributing Editor to <BugGuide.net>, sponsored by Iowa State University Department of Entomology. The identification was confirmed by "v belov", another <BugGuide.net> Contributing Editor. Because the photographs do not show much clarity, identification of the class, order, family, genus and species is probably impossible. On December 26, 2014, the <.5 mm individual shown in the 3rd and 4th photographs were found in leaf litter in the cabbage palm/oak hammock in the northeast corner of the Smith Preserve. It appeared to the webmaster to resemble the tardigrade above. On March 24, 2015, Ray Fisher, another Contributing Editor of <BugGuide.net> saw the 2nd image below and pointed out that this clearly has segmented legs, which tardigrades do not have. He thinks this is a juvenile oribatid mite. He stated, "This leads me to believe that all the photos are juvenile oribatids... not tardigrades." In conclusion, tardigrades probably exist in the Smith Preserve, but it is debatable whether any of the images shown here are of tardigrades. Return to top

© Photographs and text by Susan Leach Snyder (Conservancy of Southwest Florida Volunteer), unless otherwise credited above.

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