The Ross Seal (Ommatophoca rossii) is a rare and unique species of seal that inhabits the icy waters surrounding Antarctica. Unlike other seal species, they are solitary animals and do not form large colonies. They are named after a British explorer, James Ross, who first discovered the species in the 19th century during an expedition to Antarctica.
Ross Seals are mostly found in a remote and inhospitable habitat and thus have been relatively understudied. Thanks to the advancement of technology, such as remote sensing tools in recent years, researchers are increasingly learning more about this species.
Appearance
Ross Seals are one of the smallest seal species, with adults typically weighing between 130 and 215 kilograms (280 to 470 pounds). They measure up to 2.1 meters (6.8 feet) in length for males and up to 2.4 meters (7.8 feet) for females.
They have a distinctive appearance, with a dark brown-black coat and a silver-gray underside. They have a small, rounded head with a short, broad snout, a thick neck and enormous eyes that are adapted to see in low light conditions.
The Ross seal has a streamlined, slender body that is well-adapted for life in the water. They also have long, sensitive whiskers that they use to detect prey in the open water. They have needle-like teeth designed for catching fish and squid. Their front flippers are short and broad with five digits, while their hind flippers are narrow and pointed.
Diet
The diet of Ross Seals is an essential part of its ecology and plays a key role in shaping the species’ behavior, distribution, and survival in the Antarctic ecosystem.
They are skilled hunters and well-adapted to hunting in the cold, dark waters of the Southern Ocean. They are known to dive to depths of over 700 meters (2,290 feet) in search of food and can remain underwater for a maximum duration of 20 minutes at a time.
The Ross Seal’s diet consists of fish such as Antarctic silverfish, cephalopods like squid and invertebrates. These prey species are abundant in the waters surrounding Antarctica, particularly in areas where sea ice cover is present.
Habitat
The Ross Seal has a circumpolar distribution and is found exclusively in the Southern Ocean, around the coast of Antarctica. They are adapted to living in harsh and extreme environments and tend to inhabit areas that are covered by sea ice. They can tolerate cold temperatures due to their thick layer of blubber which provides insulation to retain body heat.
Reproduction
The reproductive behavior of Ross Seals is not well understood due to their elusive nature and remote habitat. It is thought that female Ross Seals reach sexual maturity between 2-4 years old, while males mature around 3 years of age.
Although mating has never been witnessed it is assumed to take place in water. It is known that Ross Seals display seasonal breeding and mate in mid-December, which is during the Antarctic summer when the sea ice begins to break up.
Ross Seal pups are born in October or November after a gestation period of approximately nine months. Mothers give birth to a single pup weighing around 16 kilograms (35 pounds) which they nurse for two to six weeks on high-fat milk.
Threats
Ross Seals are heavily reliant on sea ice for breeding and pupping. Continued climate warming and subsequent reduction in Antarctic pack ice pose a significant threat to their reproductive success. While their foraging habitat may be less affected by climate change compared to other seal species, the loss of breeding grounds due to diminishing sea ice could severely impact their populations. This vulnerability highlights the need for continued monitoring and conservation efforts to ensure the survival of these unique Antarctic seals in the face of a changing climate.
Quick Facts About Ross Seals
- Ross Seals belong to the scientific order Pinnipedia, together with seals, walruses, and sea lions.
- They are one of the least studied seal species due to their remote habitat and elusive behavior.
- Ross Seals were discovered by British explorer James Ross during an expedition to Antarctica in the 19th century and were named after him as well.
- They vocalise when underwater, the most common vocalizations are the “siren call.”
- Ross Seals exhibit a unique behavior by venturing away from the pack ice and foraging in open waters for a significant portion of the year, unlike other seals.
FAQs
Is the Southern Ocean and Antarctic Ocean the same?
The Southern Ocean and Antarctic Ocean are the same. It is the youngest of the five great ocean basins, formed about 34 million years ago when Antarctica separated from South America. This ocean encircles Antarctica and is generally defined as the waters south of 60° S latitude.
What adaptations do Ross Seals have?
Ross Seals are well-adapted for navigating and locating prey in the dimly lit depths of their Antarctic habitat. They have exceptionally large eyes, measuring up to 7 cm in diameter. Their pupils are wide, allowing them to gather as much light as possible in the dark waters beneath the ice. This, combined with their excellent hearing and sensitive whiskers, makes them efficient hunters even in low-light conditions.
