Pygmy right whale
The Pygmy right whale (scientific name: Caperea marginata) is a marine mammal in the family of Rorquals (Balaenoptera), part of the order of cetaceans. (which includes, dolphins, whales and porpoises).
Pygmy right whale. Source.: Robert Pitman, NOAA |
Size comparison of an average human and a Pygmy right whale. Source: Chris Huh |
Conservation Status: |
Scientific Classification Kingdom: Animalia |
Common Names: |
The Pygmy right whale is a baleen whale, meaning that instead of teeth, it has long plates which hang in a row (like the teeth of a comb) from its upper jaws. Baleen plates are strong and flexible; they are made of a protein similar to human fingernails. Baleen plates are broad at the base (gumline) and taper into a fringe which forms a curtain or mat inside the whale's mouth. Baleen whales strain huge volumes of ocean water through their baleen plates to capture food: tons of krill, other zooplankton, crustaceans, and small fish.
The IUNC Red List states that the Pygmy right whale is one of the least known baleen whale species, and there are too few records to estimate of the species population size, even to an order of magnitude. The single sighting of about 80 whales in the southeast Indian Ocean (Matsuoka et al. 1996) represents over half of the historic recorded sightings of C marginata. Apart from the two large schools mentioned above, most sightings have been of one or two individuals, sometimes in association with other species of whales and dolphins.
The inconspicuous, minute surfacing blow, along with the rapid, shallow surfacing of Pygmy right whales make C. marginata difficult to observe at sea. The species is thus difficult to be correctly identified by non-experts
Contents
Physical Description
The pygmy right whale is five to six metres in length. Distinguishing features include a small dorsal fin situated far back, and two throat grooves. Each of these features is uncharacteristic for all species of right whale, except the pygmy right whale. Other Physical Features: Endothermic; Bilateral symmetry
Behaviour
Key behaviors of this species are: natatorial; motile;and social. Very little is known about the behavior of the pygmy right whale. Because they have not been observed for extended periods, their social behaviour is very much a mystery. On one occasion, a group of eight whales was sighted; it may be that these animals were group/family living. Other right whales live in small family groups, and it is very possible that this is also true for the Pygmy right whale.
Reproduction
Little is known about the reproductive habits of the pygmy right whale. A mother bears one young per birth. If the reproductive habits of pygmy right whales resemble those of other right whales, one can infer that gestation period is probably about ten to twelve months. The offspring stay with their mother until weaning, which may take place at 6 months to one year of age.
Key Reproductive Features: Iteroparous; Gonochoric/gonochoristic/dioecious (sexes separate); Sexual; Viviparous
Distribution and Movements
The IUNC Red list reports:The pygmy right whale probably has a circumpolar distribution in temperate waters of the Southern Hemisphere between about 30°S and 55°S (extending to 20°S in at least the Benguela Current system (southwestern African continental shelf) (Hoffmann and Best 2005).
There are only a few confirmed records of live Pygmy right whales at sea, but strandings have been reported from Argentina, Falkland Islands (Malvinas), Namibia, South Africa, Chile, western, southern and eastern coasts of Australia, and North and South Islands of New Zealand (Cabrera et al. 2005; Hoffman and Best 2005; Kemper 2002a,b; Rice 1998; Ross et al. 1975). Two individuals were taken by a whaling vessel in the South Atlantic between 34°-35°S (Ivashin et al. 1972). An unusual sighting was made in 1992 of an aggregation of about 80 individuals 320 nm southwest of Cape Leeuwin, southwest Australia (Matsuoka et al. 1996). A group of fourteen individuals was sighted in 2001 at 46°S in the South Pacific 450 km southeast of New Zealand (Matsuoka et al. 2005).
Habitat
Pygmy right whales live in a pelagic aquatic habitat, in the cool to cold ocean waters surrounding Antarctica.
Food and Feeding Habits
The pygmy right whale, like most smaller baleen whales, feeds on krill. Its huge mouth takes in massive quantities of water and then filters the krill out through baleen plates, spitting the krill-free water out. Its foraging behaviour of filter-feeding captures a variety of aquatic crustaceans.
Economic Importance for Humans
This poorly known species has never been hunted commercially. There is no evidence of any direct anthropogenic threats. The species may be naturally rare throughout its range, or simply difficult to detect or identify, or perhaps its areas of concentration have not yet been discovered.
Threats and Conservation Status
The Pygmy right whale is so rare and unstudied, researchers cannot even properly classify this species as to rarity; there is no accurate census of Pygmy right whales.
References
- Caperea marginata (Gray, 1846). Encyclopedia of Life. Accessed 26 Apr 2011.
- Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008. Caperea marginata. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. . Downloaded on 26 April 2011.
- Banks, R. C., R. W. McDiarmid, and A. L. Gardner. 1987. Checklist of Vertebrates of the United States, the U.S. Territories, and Canada. Resource Publication, no. 166. 79
- Cabrera, E., Carlson, C. A., Galletti, V. M., Cardenas, J. C. and Brownell Jr., R. L. 2005. A pygmy right whale (Caperea marginata) from Chiloe Island, Chile. Scientific Committee of the International Whaling Commission, Ulsan, Korea.
- Gordon, D. (Ed.) (2009). New Zealand Inventory of Biodiversity. Volume One: Kingdom Animalia. 584 pp
- Hoffmann, M. and Best, P. B. (subeds.). 2005. Suborder Cetacea. Whales and dolphins. In: J. D. Skinner and C. T. Chimimba (eds), The Mammals of the Southern African Subregion, pp. 560-615. Cambridge University Press.
- Ivashin, M. V., Shevchenko, V. I. and Yuchov, V. L. 1972. The pygmy right whale Caperea marginata (Cetacea). Zoological Journal 51(11): 1715-1723.
- Kemper, C. M. 2002. Distribution of the pygmy right whale, Caperea marginata, in the Australasian region. Marine Mammal Science 18(1): 99-111.
- Kemper, C. M. 2002. Pygmy right whale Caperea marginata. In: W. F. Perrin, B. Wursig and J. G. M. Thewissen (eds), Encyclopedia of Marine Mammals, pp. 1010-1012. Academic Press.
- Matsuoka, K., Fujise, Y. and Pastene, L. A. 1996. A sighting of a large school or the pygmy right whale, Caperea marginata, in the southeast Indian Ocean. Marine Mammal Science 12(4): 594-596.
- Matsuoka, K., Pitman, R. L. and Marquez, F. F. C. 2005. A note on a pygmy right whale (Caperea marginata) sighting in the southwestern Pacific Ocean. Journal of Cetacean Research and Management 7(1): 71-74.
- Mead, James G., and Robert L. Brownell, Jr. / Wilson, Don E., and DeeAnn M. Reeder, eds. 2005. Order Cetacea. Mammal Species of the World: A Taxonomic and Geographic Reference, 3rd ed., vol. 1. 723-743
- Parker, ed., S. 1990. Grzimek's Encyclopedia of Mammals Volume 4. New York: McGraw-Hill, Inc.
- Perrin, W. (2010). Caperea marginata (Gray, 1846). In: Perrin, W.F. World Cetacea Database. Accessed through: Perrin, W.F. World Cetacea Database at http://www.marinespecies.org/cetacea/aphia.php?p=taxdetails&id=231424 on 2011-03-18
- Rice, Dale W. 1998. Marine Mammals of the World: Systematics and Distribution. Special Publications of the Society for Marine Mammals, no. 4. ix + 231
- Ross, G. J. B., Best, P. B. and Donnelly, B. G. 1975. New records of the pygmy right whale (Caperea marginata) from South Africa, with comments on distribution, migration, appearance, and behavior. Journal of the Fisheries Research Board of Canada 32: 1005-1017.
- Sekiguchi, K., Best, P. B. and Kaczmariuk, B. Z. 1992. New information on the feeding habits and baleen morphology of the pygmy right whale Caperea marginata. Marine Mammal Science 8: 288-293.
- UNESCO-IOC Register of Marine Organisms
- Wilson, Don E., and DeeAnn M. Reeder, eds. 1993. Mammal Species of the World: A Taxonomic and Geographic Reference, 2nd ed., 3rd printing. xviii + 1207
- Wilson, Don E., and F. Russell Cole. 2000. Common Names of Mammals of the World. xiv + 204