SEAL, NORTHERN FUR

Under Construction May 2011

NORTHERN FUR SEAL

Callorhinus ursinus

GUARD HAIR

Length: up to 20mm (ASM #3)

Diameter Range: 190 microns  (Mayer 1952). 100-160 (ASM #3) Variation in width but no shield

Medullary Index: 0.5 (ASM #3)

Medulla:  Mayer (1952) misunderstands the hair and says the medulla is present but fragmentary and occupies less than half the width of the shaft.  This misunderstanding may come from not viewing the medulla along the entire length of the shaft, as it changes considerably.  Samples from the back of the neck from ASM#3 showed a fiber where half of the sample had an interrupted medulla where the fiber was dense with red-brown pigmentation. As the hair transitioned to having sparse brown splotches of pigment the medulla appeared as large bubble-like cells that were quite distinctive-appearing almost like intestines with a very irregular and undulous perimeter.

Color: Rich red brown in the part of the hair where the medulla is interrupted, and faint/splotchy brown in section of the hair where the medulla is more intestinal-looking.

Scales: Near the base, individual diamond shaped petals with smooth margins, like a snakeskin.  Middle of the hair it changes to closely spaced parallel scales with rough margins.

 

UNDERFUR

Length: Dyed and sheared 8-10mm (ASM #2) 15-18 unsheared (ASM #3)

Diameter Range: 10-15 microns (ASM #2)

Medullary Index: No medulla

Medulla: No medulla

Color: Dyed black sample appears a bit purplish in transmitted light, with the tips of the scales appearing to hold more of the dye than the rest of the petal-shaped scale.  Dyed brown one shows (not surprisingly) a brownish coloration, but the fiber has brown colored dots and dashes that are inconsistent throughout each petal-like scale.

Scales: Clearly visible as flower petal-like where each petal has its own tip. It appears as though there are at least two to three petals going around the circumference of the shaft.  Dyed hairs show color in the scales of the cuticle, otherwise cuticle layers of animals are typically not pigmented.

Macro Qualities: 3.5 – 4.5 feet long (Forsyth 1999). Males tend to be black on the back with brown-red coloration underneath and a grizzled gray neck/shoulder area.  Females are usually gray above and reddish below.  Pups are black and then later silver (Forsyth 1999).  Aside from black, albinos and chocolate coloration also known.  Sometimes the fur is light brown with white-tipped guard hairs.  No spots.  Sometimes dyed.  Longer guard hairs sometimes removed when commercially processed (ADF&G 2008).  “Seal dye” or “seal brown” means black tips and glossy brown base.  “Safari” means reddish brown.  “Matara” means grayish.  Stiff guard hairs are plucked out.  The headquarters for processing these pelts was London up until around 1913, and then it became St Louis.  Good “serviceability” (Bachrach 1953). On one taxidermy specimen, guard hairs are dark gray with pale tips on the back and the chest and underbelly is pale and creamy colored.  The fur gets chocolatey brown only near the flippers (ASM #3).

Cultures: For example: For the fur trade, the most desired fur comes from 3 year old bachelor males.  Males don’t breed until 6-7 years old, when they begin to fight more and develop scars.  He also describes the fur as having “double fur action” meaning that the hand may be rubbed in either direction  (Samet 1950).

Notes: ASM #1 is a brown fur from the ASM education collection pelt ring; ASM #2 is also from the pelt ring but black in color, ASM #3 is from a taxidermy mount at ASM off site storage.

Troubleshooting: Otariid seal guard hair has a medulla, while Phocid seal guard hair does not.  Can look similar to otters in that the medulla is narrow, but in otters it gets wider at the tip end because otter guard hair has a shield and seal hair does not.  If only underfur is available, the otters and fur seal are difficult to distinguish.  All have pointed petal scales, no medulla, and similar width, although fur seal underfur has more of the wider hairs in the 15 micron range.  Underfur length may be helpful, as fur seal rarely exceeds about 18mm while sea otter may reach 25mm and river otter rarely exceeds 10mm.  River otter has less pigment in the underfur than sea otter or fur seal.

Range: Aleutian islands, coastal areas of Southern Alaska and the Panhandle. (Forsyth 1999)  Common in the Pribilof Islands, with over 2/3 of the population there  (ADF&G 2008).  Found on the 3 of the 5 Pribilof Islands: St George, St Paul and Sea Lion Rock  (Bachrach 1953).

Names: Suborder/superfamily Pinnipedia (the pinnipeds)  Family Otarvidae (the otarvids) Callorhinus alascanus seems to be the Pribilof fur seal?  Also known as the Alaska Fur Seal (Forsyth 1999). Laqux is another name.  The only “fur seal” found in Alaska, so-called for the thick underfur which can be 350,000 hairs per square inch.  Other seals are called “hair seals” because they lack dense underfur (ADF&G 2008).  Coats marketed as “Alaska Seal Coats” are this animal.  Also called Rock Seal. (Bachrach 1953).  Alaska Seal (Samet 1950).

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