Moult in the Mediterranean monk seal from Cap Blanc, western Sahara

Abstract

At birth, the Mediterranean monk seal (Monachus monachus) is covered with dark lanugo This is shed earlier and faster in females, so they complete the moult when they are significantly younger (64 days) than males (82 days). Moulted pups present a greyish dorsal and a white ventral pelage. Only the hair is shed in the first moult. In subsequent moults, the hairs are shed along with large sheets of cornified epidermis. A series of sequential stages were identified, which included a long pre-moult phase (brown pelage) and a post-moult phase (dull appearance). The shedding process lasted 15 days. It is different to that of the Hawaiian monk seal and elephant seals, as Mediterranean monk seals partly moult in the water. The intermoult period was close to one year except in females nursing a pup. Such females have longer intermoult periods and can even moult whilst still lactating. In males, the process of developing the mature pelage pattern of bulls is gradual. It involves at least two annual moults and can be completed by the age of 4 years.