Juvenile molting of the spotted seal (Phoca largha)

Based on observations of mother – newborn pairs (n=16), the author describes the nature of the spotted seal (larga) first postnatal molt: its timing, duration and sequence. Juvenile hair loss (lanugo) begins 18–27 days after birth and coincides with the end of lactation, when the pup subcutaneous fat layer thickness reaches its maximum. First, pups lose hair covering the snout, flippers and tail, and then on the body. The molting process lasts 5–6 days and ends with the complete hair loss. The molting topography for normally developed and retarded pups is different. In malnourished puppies, the molting process is disrupted as a result of the animal’s exhaustion and painful condition. The molted pup hairline is indistinguishable from that of an adult seal, and the unique pattern on each seal’s skin remains throughout its life. Information on the pups’ fur coat condition and difference in the juveniles timing of molting can be useful in studying the local reproductive groups of seals intra-population structure.