We'd like to understand how you use our websites in order to improve them. Register your interest. During the first few weeks of March the seals were moving in the pack ice along the continental shelf edge, close to the coast of Queen Maud Land. In the first half of June the two remaining seals turned south and moved back deep into the pack ice. The seals made about dives per day each throughout the study period. Ninety percent of these were made to depths of less than 52 m.
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These fascinating seals measure 2. Males and females are generally close in size with females typically slightly heavier. After the molting season, the back fur of the crabeater seal is dark brown fading to blond on its belly. These seals also have dark brown markings along the back and sides. Their flippers are very dark brown.
The fur lightens throughout the year becoming completely blond in summer just before molting. Crabeaters have a long snout and slender body. Because they live in remote, harsh environments, the exact population size of this species is unknown. Original estimates place the population at approximately 15 million, however it is now thought that the population is much smaller. Crabeater seals migrate seasonally according to the movement of the pack ice.
Crabeater seals are typically solitary animals, however they are also known to gather into aggregations of about 1, animals. They dive to feed on krill at night. They are known to dive for long periods of time up to 16 hours for feeding, traveling or migrating, and exploring. The dives range between 10 m for traveling dives, 30 m for food, and slightly deeper for exploratory dives. Crabeater seals have been known to use breathing holes in the ice created by Weddell seals, Leptonychotes weddellii and in some cases may chase juvenile Weddell seals away from their breathing holes.
At the end of the summer when the ice begins to freeze, crabeater seals begin to travel north. Some crabeaters have been known to become disoriented traveling south on the pack ice instead of north hundreds of kilometers inland. These are mostly juveniles and they usually die as a result of their misdirection. They are a highly mobile and fast pinniped that can travel up to 25 kph. When crabeater seals travel at this speed, they lift and swing their head from side to side moving their foreflippers across the ice to navigate with their hind flippers elevated behind them to avoid drag.
Crabeater seals have distinctive and complex teeth. Each tooth has tubercles, or bony protuberances, with spaces between them. The upper and lower jaws fit together so that when mouth is closed, the teeth and tubercles can strain krill. As mentioned previously, krill, such as Euphausia superba , not crabs, are the primary food source for crabeater seals.
They feed by swimming through schools of krill with their mouth open, sieving the water out using their sophisticated teeth.
When they migrate outside the Antarctic, crabeater seals are thought to feed on other invertebrates as well as small fishes.
They feed primarily at night, typically all night long, hauling out on the ice to rest during the day. Crabeater seals are preyed on by orca killer whales and leopard seals. To deflect an attack, the crabeater seal will bare its teeth and snort or hiss when approached.
They also tend to roll over to avoid being tackled by their predators. Crabeater seals are thought to reproduce in Antarctica on the pack ice during the early Spring months between October and December. Unlike other seal species, crabeaters tend to mate on the ice rather than in the water.
In September, following an month gestation period, females give birth to a single pup on an ice floe. Pups are born about 1. The mother and her pup stay in close contact for the duration of the nursing period, which lasts about 3 weeks. A male crabeater seal, usually not the father, will join the female just before or just after she gives birth to protect the mother and her pup. Soon after weaning, females are ready to breed again, and, although her protective male defends her from the aggression of other males, he is typically aggressive toward the female during the nursing period.
Crabeater seals reach sexual maturity between 3 and 4 years of age. Females have successful pregnancies when they are between 5 and 25 years old. The crabeater seal, Lobodon carcinophagus , is one of the most abundant pinniped species.
Some krill-fishing nations are seeking an increase in krill quotas in Antarctica. The krill fishery has been on the rise since the mids and new techniques have been developed that process krill for fish feed. Another potential threat to crabeaters is global warming , which is impacting ocean ecosystems sooner and more seriously than originally anticipated.
This trend could potentially decrease pack ice, which will decrease the habitat of crabeaters and other species. In addition, krill may suffer in warmed waters, which would reduce the food supply for this and many other marine species. Crabeater seals are not commonly hunted commercially because of their remote habitat. The habitat of the crabeater seal is protected by such legislation as the January Environmental Protection Protocol to the Antarctic Treaty, which bans mining and oil drilling in Antarctica for at least 50 years.
The treaty also bans refuse disposal and the use of pesticides in the region. It is thought that crabeaters are abundant because of the near-extinction of large baleen whales, which also feed on krill. The decrease in the number of baleen whales has increased the availability of krill.
Some scientists also attribute the reduction in the age of sexual maturity of crabeater seals to the increase in its primary prey. Seal Conservation Society: Description and status of the Crabeater Seal Photos by Marine Team — a network of professionals working in the marine environment who are dedicated to the conservation of marine species and their habitat.
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These fascinating seals measure 2. Males and females are generally close in size with females typically slightly heavier. After the molting season, the back fur of the crabeater seal is dark brown fading to blond on its belly. These seals also have dark brown markings along the back and sides. Their flippers are very dark brown. The fur lightens throughout the year becoming completely blond in summer just before molting.
Food and Agriculture Organization of the United Nations for a world without hunger. Fisheries and Aquaculture Department. Print PDF. Search species. Site map.
The crabeater seal Lobodon carcinophaga , also known as the krill-eater seal , is a true seal with a circumpolar distribution around the coast of Antarctica. They are medium- to large-sized over 2 m in length , relatively slender and pale-colored, found primarily on the free-floating pack ice that extends seasonally out from the Antarctic coast, which they use as a platform for resting, mating, social aggregation and accessing their prey. They are by far the most abundant seal species in the world. While population estimates are uncertain, there are at least 7 million and possibly as many as 75 million individuals. Indeed, its scientific name, translated as "lobe-toothed lobodon crab eater carcinophaga ", refers specifically to the finely lobed teeth adapted to filtering their small crustacean prey. The genus name of the crabeater seal, Lobodon , derives from Ancient Greek meaning "lobe-toothed", and the species name carcinophaga means "crab eater. These include the leopard seal Hydrurga leptonyx , the Ross seal Ommatophoca rossii , and the Weddell seal Leptonychotes weddelli.