sharing our knowledge.
Photographic gallery.  Thousands of particles under the microscope.
Muskrat Hair

Muskrat Hair, Guard Hair Scale Cast

This is from the McCrone Hair Standards set, slide #35. This image is near the root end of the hair.

Transmitted Oblique Off Crossed Circular Polarized Light


KINGDOM: Animalia PHYLUM: Chordata CLASS: Mammalia ORDER: Rodentia SUPERFAMILY: Muroidea FAMILY: Cricetidae SUBFAMILY: Arvicolinae TRIBE: Ondatrini GENUS: Ondatra SPECIES: zibethicus

Significance in the Environment:

This is a common fur used in coats, wraps, and as trim on clothing. Its presence in an indoor environment is generally indicative of clothing rather than the presence of the animal. Muskrats are also a food source in some regions of the US, Europe, and Asia.

Characteristic Features:

Muskrat guard hair is around 30 to 80 micrometers wide near the root and expands or decreases to about 50 for the next half of the length. It then expands to over 100 micrometers before tapering to the tip. The medulla of the guard hair begins as a multiserial discontinuous ladder and then becomes a continuous multiserial ladderlattice until the final expansion where it becomes a cross between a latice and a multiserial ladder. Toward the tip the medulla becomes discontinuous and then disappears. The cuticle in imbricate and crenate over most of the fiber length but may begin near the root as imbricate elongate. Pigment varies from dark and heavy to light.

The fleece hair is around 10 micrometers of its entire length. The cuticle pattern is coronal simple with a count of from 7 to 12 scales per 100 micrometers. There is a concentration of pigment in the medulla in the typical rodent pattern and the medulla is uniserial ladder for most if not all of its length. The rungs may become angled. Away from the proximal end of the fiber the cuticle may become pigmented as well as the medulla.

Muskrat hair has a refractive index along its length of about 1.56 and perpendicular to its length of about 1.55. It has a birefringence of about 0.01 and a positive sign of elongation.

Associated Particles:


References with Photographs and/or Drawings

Hausman, Leon Augustus, "Structural charactreistics of the hair of mammals", THE AMERICAN NATURALIST, vol. 54, no. 635, pp.496-523,

Hausman, Leon Augustus, "Recent studies of hair structure relationships", THE SCIENTIFIC MONTHLY, pp. 258-277,

Glaister, John, A STUDY OF HAIRS AND WOOLS, Misr Press, Cairo, 1931.

Click here for the FBI site for Animal Hair Identification.

Keys Only

Mayer, William V., "The hair of California mammals with keys to the dorsal guard hairs of California mammals", THE AMERICAN MIDLAND NATURALIST, vol. 48, no. 2, pp. 480-512, 1952.

Stains, Howard J., "Field key to guard hair of middle western furbearers", JOURNAL OF WILDLIFE MANAGEMENT, vol. 22, no.1, pp. 95-97, January, 1958.

Mathiak, Harold A., "A key to hairs of the mammals of southern Michigan", JOURNAL OF WILDLIFE MANAGEMENT, vol. 2, no. 4, pp. 251-268, October, 1938.