By Kathi Hull
Geographic Range
The Round-Tailed Muskrat or Florida Water Rat is found in the mainland and islands of Florida and Southern Georgia, but nowhere else in the world.
Biogeographic Regions
nearctic 
(Native )
Habitat
Wet moist areas on mainland and islands. In particular, brackish waters of river deltas and swamps, as well near freshwater bogs, marshes, and around lakes with sandy bottoms and lots of aquatic vegetation. (Palmer 1954, GMNH 1999).
Terrestrial Biomes
forest
Physical Description
Unlike the muskrat, the Round-tailed muskrat has a tail that is truly round in cross-section, not flattened on the sides. It is also smaller than the muskrat, with a total body length of 381 - 546 mm (15 - 21.5 inches).
The outer fur (coarse guard hairs) is dark brown and glossy, while the dense undercoat is brown becoming gray at the base
The belly is a pale buff color.
(GMNH 1999)
Reproduction
Breeding occurs year round, though there is a peak in the fall. Gestation is 26 to 29 days. Females can produce 4 to 6 litters each year, with 1 to 4 (possibly as many as six) young per litter. Young are weaned by 21 days and become sexually mature at 90 - 100 days.
(Palmer 1954, GHNH 1999).
Behavior
The round-tailed muskrat builds dome-shaped lodges made of aquatic vegetation over sphagnum moss at the bases of cypress trees or clumps of grass brush. A lodge usually has two underwater exits/entrances. Inside is a grass-lined nest chamber. Nearby are feeding platforms, elevated slightly from water, also built from matted grass. Exit holes from these platforms allow the round-tailed muskrat to evade predators such as herons, owls, hawks, snakes, and bobcats.
They are nocturnal or crepuscular, with most activity occuring just after dark and before dawn. (GMNH 1999)
Food Habits
They are vegetarian. The diet consists mainly of aquatic grasses as well as roots, stems, and seeds. (GMNH 1999)
Economic Importance for Humans: Positive
There are not any recognized benefits to humans at this time. It is not important in the fur trade.
Economic Importance for Humans: Negative
At this time, Round-Tailed Muskrats do not cause any significant damage or benefit to humans, but it does harm sugarcane, tomatoes, and beans. However, it is possible that some of the damage supposedly caused by this muskrat is actually caused by the Cotton Rat (Gingerich 1994).
Conservation Status
IUCN Red List of Threatened Species [Link]
Least Concern
More Information
US Federal List [Link]
Threatened
The round-tailed muskrat is listed as a threatened species in the state of Georgia. It cannot be trapped or hunted. (GMNH 1999)
Other Comments
Neofiber combines Greek and Latin and means "new beaver." The species name, alleni is after the famous mammalogist, Arthur A. Allen. (GMNH 1999)
For More Information
Find Neofiber alleni information at
Contributors
Kathi Hull (author), Cocoa Beach High School, Penny Mcdonald (editor), Cocoa Beach High School.
