Caspian Seal, Pusa caspica
The Caspian seal (Pusa caspica) is one of the smallest species in the true seal family that is native only to the Caspian Sea. It can be seen on shorelines, rocky islands, and ice blocks that occur throughout the sea. In warmer months, these seals will inhabit northern areas of this range, but in colder months, they inhabit cooler waters and the mouths of the Ural and Volga rivers. It is thought that these seals only occur in the Caspian Sea because they moved there during the Quaternary period when water levels were high.
The Caspian seal can reach an average body length of up to 4.9 feet, with a weight of up to 190 pounds. Males are typically larger than females. It typically dives to a depth of up to 164 feet, although it may dive deeper if necessary. Its diet consists of crustaceans, cyprinids, and gobis and it will move into freshwater estuaries and rivers to consume roach, carp, and pikeperch. Like other species of seal, the Caspian seal is sociable and gathers in large groups. Pups are born after eleven months of pregnancy and are similar in appearance to ringed seals, having white fur. This fur is molted at three to four weeks of age. Males reach sexual maturity at six or seven years of age, while females are able to breed at five years of age.
The Caspian seal is threatened by hunting and disease, particularly the canine distemper virus. During a three-week period in February of 1978, seventeen to forty percent of Astrakhan’s population of this species was killed by wolves, but not consumed. This species is also hunted by sea eagles, although pups are most often targeted. Hunting conducted by humans does a pose a threat, but habitat degradation caused by industrial growth is now its major threat. Pollution and other factors have caused these seals to have lower immune systems, which causes an increased risk of disease. In the 1980’s it was estimated that total population of Caspian seals numbered only 400,000, a decrease from 1.5 million from the century before. The Caspian seal appears on the IUCN Red List with a conservation status of “Endangered.”
Image Caption: Caspian Seal. Credit: Nanosanchez/Wikipedia