Ross Seal
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 Ross seal (Ommatophoca rossii)
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| Ommatophoca rossii (Gray, 1844) |
The Ross Seal (Ommatophoca rossii) is a carnivorous seal of the family Phocidae and only species of the genus Ommatophoca. It is named after Sir James Clark Ross, who led the erebus and terror expeditions to the Antarctic. It is native to the Antarctic, including the Ross Sea, from which its name is derived.
[edit] Description
Ross seals are notably smaller than other Antarctic seals, reaching a length of about 2 m long and a weight of 200 kg. The coat is coloured dark-brown in the dorsal area and silvery-white beneath. At the onset of the Antarctic winter the coat fades gradually to become light brown. At close range, the Ross seal can be easily identified by its large eyes, which are up to 7 cm in diameter.
The Ross Seal is able to produce a variety of twittering sounds which carry a long distance underwater. The purpose of these sounds is unknown, though possibly they play a role in territoriality.
[edit] Habitat and behaviour
Although Weddell Seals, Crabeater Seals and Leopard Seals are ubiquitous in Antarctic waters, the Ross Seal is an uncommon and relatively unknown animal, considered to be the least common pack ice seal. It almost never leaves the Antarctic Ocean, with the very rare exception of stray animals found around sub-antarctic islands, and uniquely, off the south coast of Australia.
The Ross Seal hunts by diving for cephalopods and fish, and occasionally krill. It specialises more than other seals in hunting squid, which forms about two thirds of its diet. In common with other Antarctic seals, the Ross Seal is preyed upon by Killer Whales and Leopard Seals.
In November the females give birth to their young on the ice. The pup is nursed for only four weeks and then left alone, shortly after which the female will mate underwater with a new partner. Within three years, the Ross Seals are in their adolescence.
The life expectancy of a Ross Seal is thought to be around 20 years.
[edit] References and external links
- Seal Specialist Group (1996). Ommatophoca rossii. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006.
- University of Michigan museum of zoology
- Seal conservation society webpage
- Fisheries Global Information System factsheet
