SEAL, SPOTTED

Under Construction May 2011

SPOTTED SEAL

Phoca largha

GUARD HAIR

Length: less than 10mm, tips often broken off in phocidae (Mayer 1952) 5-8 (ASM #1)

Diameter Range: 160-200 microns (ASM # 1)  140-180mm (ASM #2) 

Medullary Index: N/A

Medulla: None

Color: Small brown dashes and specks throughout the majority of the length of the fiber. Pigmentation is absent at the very tip and it lessens by the proximal end of the fiber. The root shows brown pigmentation (ASM #1). 

Scales: Closely spaced, generally parallel edges, margins can be smooth at tip and base but rough margins in the middle.  Sometimes scales don’t seem to change much in appearance along the length of the shaft.

UNDERFUR

Length: 3-5mm (ASM #1)

Diameter Range: 22.5-37.5 microns (ASM#1) 25-30 microns (ASM #2)

Medullary Index: N/A

Medulla: No medulla

Color: In the middle section, pigmented brown, less at the tips and base.

Scales: stacked crowns, but some look to have scales 2-3 across

Macro Qualities: Up to 5 feet long. Smaller than bearded seals and harbor seals but larger than ribbon seals and ringed seals.  Closely related and often confused with harbor seals.  Fur has a silvery background that is darker on the back of the animal and is broken up by various spots and splotches.  Spotted seal pups are born with a soft white coat (lanugo,) but harbor seal pups shed this before birth. Spotted seals shed the lanugo around 4 weeks of age (ADF&G 2008).

Cultures: For example: Iñupiaq, Yup’ik, and Cup’ik.  In present day, spotted seals are hunted from Togiak to Kaktovik on the coast and skins are used for clothing, equipment and crafts  (ADF&G 2008).

Notes: Earless seals (Phocidae) often have hairs with broken off distal tips.  Spotted seal can be readily distinguished from harbor seal by hunters familiar with the animals.  There is some habitat overlap in Bristol Bay, and the animals might even be able to interbreed.  Spotted seals are essentially a cousin of the harbor seal who has moved further north and started pupping on the ice. 

Notes: ASM #1 is a sample from the education collection IIE184,  ASM#2 is from a spotted seal hat made by Martina John from the Bering Sea area.

Troubleshooting: Otariid seal guard hair has a medulla, while Phocid seal guard hair does not. Spotted seals are NOT the only seals with spots.  Frayed tips of both guard and underfur common.  Differentiating between the Phocid seals under the microscope is difficult, with length and width measurements on guard hairs and underfur being in similar ranges for all the true seals in Alaska.  Scale patterns are similar, and none have medullas.  Ribbon and ringed seals often have distinct pelt markings.  The bearded seal fur may be special in that individual guard hairs tend to be widely spaced and the underfur curlier and denser than other seals, giving a less “smooth” flat fur look, but more investigation is needed to confirm this observation.

Range: Bering Sea and Bristol Bay year round, Chukchi and Beaufort Seas in summer.  (ADF&G 2008).

Names: Suborder/superfamily Pinnipedia (the pinnipeds) Family Phocidae (the phocids, or “earless seals”)  qasigiaq (inupiaq), issuriq (Yup’ik), gazigyaq (St Lawrence Island Yup’ik) and issuri (Nunivak Island Cup’ig) (ADF&G 2008).  “Ice seals” include ringed seals, ribbon seals, spotted seals and bearded seals.  These are also known as “hair seals” or “true seals” (ADF&G 2008).

Advertisements

Post a Comment

Required fields are marked *

*
*

%d bloggers like this: