|Last modified: Thursday September 24th, 1999
Hydrurga leptonyx (deBlainville, 1820)
The first generic name given to this species was Stenorhinque, by Cuvier in 1824. This name was
however already used (for some crustaceans and insects) In 1899 T. Palmer
showed that Hydrurga (which means water worker) was the correct generic name.
Male leopard seals can be as long as 250-320 cm and weigh 200-455 kg. Females measure 241-338 cm and weigh 225-591 kg. Pups are 150-160 cm long and weigh up to 35 kg. The leopard
seal is characterized by its long streamlined body and the massive, almost reptilian looking head.
The nostrils are positioned on top of the muzzle. There is no obvious forehead. This seal has a
massive lower jaw, a long neck and a large gape. The seal is silvery dark-grey coloured dorsally,
somewhat lighter ventrally, and spotted (counter-shaded). They have long fore-flippers (about 1/3
of the body length).
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The canines are long (up to 2.5 cm). The other teeth are multi-lobed.
The leopard seal has a circumpolar distribution and is usually found near the Antarctic pack ice. It
is regularly spotted at Macquarie Island and on subantarctic islands.
The leopard seal may be migratory. There is a segregation by age-class. Young seals may reach
the South African and Australian coasts as stragglers.
The leopard seal is an opportunistic predator, which feeds on Adelie penguins, krill and seals,
especially crabeater seals.
Population dynamics and life history
The age at maturity is probably 3-7 years for females and 2-6 years for males. Longevity is over
26 years. The mortality rate for age 0-1 is 25%, for age 1-10: 8% and for ages over 10 years: 5%.
This species reproduces from September through January. For the rest of the year they are
solitary. Unlike other phocid seals, the leopard seal uses its large fore-flippers while swimming
(sea lion style).
The population size is probably around 222,000.
Some seals are taken for research purposes and some for dog food, but otherwise there is no
catch of leopard seals. The population is not protected or regulated.
Threats to the population
None. Future krill exploitation will have negative effects, directly and indirectly on the food
supply of the leopard seal.
- Bonner, W.N. (1982)
- Seals and Man. A study of interactions. University of Washington Press, Seattle, 170pp.
- Hofman, R.J. (1979)
- Leopard Seal. in: Mammals in the Seas, volume II: pinniped species summaries and report on
sirenians. FAO Fisheries Series No. 5, Vol II, pp. 125-129
- King, J.E. (1983)
- Seals of the world, 2nd edition. British Museum (Natural History), London and Oxford University
Press, Oxford, 240pp.
- Kooyman, G.L. (1981)
- Leopard Seal, Hydrurga leptonyx, Blainville, 1820. in: Ridgway, S.H. and Harrison, R.J. (eds.):
Handbook of Marine Mammals, vol. 2: Seals, pp. 261-274, Academic Press Inc., Ltd, London
- Reijnders, P.J.H., S. Brasseur, J.D. van der Toorn, P. van der Wolf, I.L. Boyd, J. Harwood, D.M. Lavigne and L.F. Lowry. 1993.
- Seals, Fur Seals, Sea Lions, and Walrus. IUCN/SSC Seal Specialist Group, Gland, Switzerland. 88 pp.