Caspian Seal (Pusa caspica)
Caspian Seals (Pusa caspica) are endemic to the Caspian Sea, which sits between southeastern Europe and western Asia. The Caspian Sea rests between multiple countries and is surrounded by land, and therefore only slightly saline, making it often described as a brackish lake rather than a sea. Due to hunting, by-catch, and other ongoing issues, P. caspica are listed as an Endangered species by the IUCN. Estimated population size = 104,000.
P. caspica are a small true seal (males ♂ up to 1.5 m long/ 86 kg, females ♀ up to 1.4 m/ 86 kg) with short, square-ended flippers at the front and back. Their bodies are small but round and their heads are also small with a fairly pointed muzzle, big, doe eyes, and long white whiskers. Their colouration can vary from almost yellowish brown to dark grey, usually paler on the undersides, and often sporting spots or blotches of darker brown or black.
Prey choice is predominantly fish, but species vary with seasonal availability and P. caspica will migrate around the sea to find abundances of food at different times. Foraging is primarily benthic and specific species found with high frequency in the diet include herring, roach and goby.
Sexual maturity – males ♂ 6-8 years old/ females ♀ 5-7 years old.
Mating occurs in the water, and unlike many other pinniped species, a lack of sexual dimorphism and no sign of agonistic behaviour during courtship, indicates that there is little to no rivalry between males. Some studies have shown individuals of each sex pairing up to breed, however it is unknown whether the male has then gone on to mate with other females during the same season, and it is certainly possible. Therefore it cannot be determined whether P. caspica are monogamous or polygynous at this time. Gestation lasts for 11 months, which likely includes a period of delayed implantation, and pups are born directly on the ice during January and February. Like other cold-climate pups, P. caspica have a warm, white lanugo for the first 3 weeks of life, which is then moulted to reveal a shorter, silvery grey coat that enables them to enter the water. Weaning occurs gradually, after between 3 and 5 weeks (likely dependant on ice melt) and at this point pups must feed and fend for themselves. An annual moult takes place during April and May. The average lifespan for P. caspica is between 25 and 35 years, with males at the shorter end of the spectrum and females a little longer-lived. However, there have been records of individuals reaching up to 56 years of age.
P. caspica represent a single species with no sub-divisions.
Photos: Iran Caspian Seal Conservation Center