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Encyclopedia > Marine mammal
A Humpback whale (Megaptera novaeangliae), a member of Order Cetacea
A Humpback whale (Megaptera novaeangliae), a member of Order Cetacea
A Leopard seal (Hydrurga leptonyx), a member of infrafamily Pinnipedia
A Leopard seal (Hydrurga leptonyx), a member of infrafamily Pinnipedia
A West Indian Manatee (Trichechus manatus), a member of Order Sirenia
A West Indian Manatee (Trichechus manatus), a member of Order Sirenia
A pair of Sea Otters (Enhydra lutris), a member of family Mustelidae
A pair of Sea Otters (Enhydra lutris), a member of family Mustelidae
A Polar bear (Ursus maritimus), a member of family Ursidae
A Polar bear (Ursus maritimus), a member of family Ursidae

A marine mammal is a mammal that is primarily ocean-dwelling or depends on the ocean for its food. Mammals originally evolved on land, but later marine mammals evolved to live back in the ocean. Image File history File links Download high-resolution version (1542x866, 195 KB) Humpback Whale, Megaptera novaeangliae. ... Image File history File links Download high-resolution version (1542x866, 195 KB) Humpback Whale, Megaptera novaeangliae. ... Binomial name Borowski, 1781 Humpback Whale range The Humpback Whale (Megaptera novaeangliae) is a baleen whale. ... Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea (IPA: , L. cetus, whale) includes whales, dolphins and porpoises. ... Image File history File links Download high resolution version (3102x2154, 718 KB) fr: Léopard de mer (Hydrurga leptonyx ) en: Leopard seal (Hydrurga leptonyx) scan de photo : B.navez - Kerguelen - 1999 File links The following pages link to this file: Pinniped ... Image File history File links Download high resolution version (3102x2154, 718 KB) fr: Léopard de mer (Hydrurga leptonyx ) en: Leopard seal (Hydrurga leptonyx) scan de photo : B.navez - Kerguelen - 1999 File links The following pages link to this file: Pinniped ... Binomial name (Blainville, 1820) Hydrurga leptonyx range map. ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Image File history File links FL_fig04. ... Image File history File links FL_fig04. ... Binomial name Trichechus manatus Linnaeus, 1758 A group of three West Indian manatees. ... Families Dugongidae Trichechidae Hydrochichus (extinct) For information about the Gothic metal band, see Sirenia (band) The Sirenia are fully aquatic, herbivorous mammals that inhabit rivers, estuaries and coastal marine waters. ... [1] File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... [1] File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Binomial name Enhydra lutris (Linnaeus, 1758) The Sea Otter (Enhydra lutris) is a large otter native to the North Pacific, from northern Japan and Kamchatka west across the Aleutian Islands south to California. ... Subfamilies Lutrinae Melinae Mellivorinae Taxidiinae Mustelinae Mustelidae is a family of carnivorous mammals. ... Image File history File links Metadata Size of this preview: 667 × 599 pixelsFull resolution (3160 × 2840 pixel, file size: 297 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Metadata Size of this preview: 667 × 599 pixelsFull resolution (3160 × 2840 pixel, file size: 297 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... This article is about the animal. ... For other meanings, see Bear (disambiguation). ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... Animated map exhibiting the worlds oceanic waters. ...


There are five groups of marine mammals:

  1. Order Sirenia: the manatee, dugong.
  2. Order Carnivora, family Ursidae: the polar bear
  3. Order Carnivora, superfamily Pinnipedia: the seal, sea lion, and walrus
  4. Order Carnivora, family Mustelidae: the Sea Otter and Marine Otter
  5. Order Cetacea: the whale, dolphin, and porpoise

Since different groups of marine mammals originate from different ancestors, this is a case of convergent evolution. In scientific classification used in biology, the order (Latin: ordo, plural ordines) is a rank between class and family (termed a taxon at that rank). ... Families Dugongidae Trichechidae Hydrochichus (extinct) For information about the Gothic metal band, see Sirenia (band) The Sirenia are fully aquatic, herbivorous mammals that inhabit rivers, estuaries and coastal marine waters. ... For other uses, see Manatee (disambiguation). ... Binomial name (Müller, 1776) Natural range of . ... Families 17, See classification The diverse order Carnivora (IPA: or ; from Latin carō (stem carn-) flesh, + vorāre to devour) includes over 260 species of placental mammals. ... The hierarchy of scientific classification In biological classification, family (Latin: familia, plural familiae) is a rank, or a taxon in that rank. ... For other meanings, see Bear (disambiguation). ... This article is about the animal. ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... For other uses, see Sea Lion (disambiguation). ... Binomial name (Linnaeus, 1758) Distribution of Walrus Subspecies Walruses (Odobenus rosmarus) are large semi-aquatic mammals that live in the cold Arctic seas of the Northern Hemisphere. ... Subfamilies Lutrinae Melinae Mellivorinae Taxidiinae Mustelinae Mustelidae is a family of carnivorous mammals. ... Binomial name Enhydra lutris (Linnaeus, 1758) The Sea Otter (Enhydra lutris) is a large otter native to the North Pacific, from northern Japan and Kamchatka west across the Aleutian Islands south to California. ... Binomial name (Molina, 1782) Marine Otters (Lontra felina) are rare and poorly-understood marine mammals of the weasel family (Family Mustelidae). ... Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea (IPA: , L. cetus, whale) includes whales, dolphins and porpoises. ... This article is about the animal. ... Genera See article below. ... Genera Neophocaena Phocoena - Harbor porpoise Phocoenoides - Dalls porpoise The porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. ... In evolutionary biology, convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. ...


Since mammals originally evolved on land, their spines are optimized for running, allowing for up-and-down but only little sideways motion. Therefore, marine mammals typically swim by moving their spine up and down. By contrast, fish normally swim by moving their spine sideways. For this reason, fish mostly have vertical caudal (tail) fins, while marine mammals have horizontal caudal fins. The vertebral column seen from the side Different regions (curvatures) of the vertebral column The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ...


Some of the primary differences between marine mammals and other marine life are:

  • Marine mammals breathe air, while most other marine animals extract oxygen from water.
  • Marine mammals have hair. Cetaceans have little or no hair, usually a very few bristles retained around the head or mouth. All members of the Carnivora have a coat of fur or hair, but it is far thicker and more important for thermoregulation in Sea Otters and Polar Bears than in seals or sea lions. Thick layers of fur contribute to drag while swimming, and slow down a swimming mammal, giving it a disadvantage in speed.
  • Marine mammals have thick layers of blubber used to insulate their bodies and prevent heat loss. Sea Otters and Polar Bears are exceptions, relying more on fur and behavior to stave off hypothermia.
  • Marine mammals give live birth. Most marine mammals only give birth to one calf or pup at a time, and are never able to birth twins or larger litters.
  • Marine mammals feed off milk as young. Maternal care is extremely important to the survival of offspring that need to develop a thick insulating layer of blubber. The milk from the mammary glands of marine mammals often exceeds 40-50% fat content to support the development of blubber in the young.
  • Marine mammals maintain a high internal body temperature. Unlike most other marine life, marine mammals carefully maintain a core temperature much higher than their environment. Blubber, thick coats of fur, bubbles of air between skin and water, countercurrent exchange, and behaviors such as hauling out, are all adaptations that aid marine mammals in retention of body heat.

The polar bear spends a large portion of its time in a marine environment, albeit a frozen one. When it does swim in the open sea it is extremely proficient and has been shown to cover 74 km in a day. For these reasons, some scientists regard it as a marine mammal. Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea (IPA: , L. cetus, whale) includes whales, dolphins and porpoises. ... Families 17, See classification The diverse order Carnivora (IPA: or ; from Latin carō (stem carn-) flesh, + vorāre to devour) includes over 260 species of placental mammals. ... Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when temperature surrounding is very different. ... Binomial name Enhydra lutris (Linnaeus, 1758) The Sea Otter (Enhydra lutris) is a large otter native to the North Pacific, from northern Japan and Kamchatka west across the Aleutian Islands south to California. ... This article is about the animal. ... Families Odobenidae Otariidae Phocidae Pinnipeds (fin-feet, lit. ... Genera Eumetopias Zalophus Otaria Neophoca Phocarctos A sea lion rookery at Monterey, California A sea lion is any of several marine mammals of the family Otariidae. ... Remains of seventeenth century blubber cauldrons at the abandoned Dutch settlement of Smeerenburg in Svalbard, Norway This article is about the body tissue. ... This article is about the animal. ... Remains of seventeenth century blubber cauldrons at the abandoned Dutch settlement of Smeerenburg in Svalbard, Norway This article is about the body tissue. ... Mammary glands are the organs that, in the female mammal, produce milk for the sustenance of the young. ... Remains of seventeenth century blubber cauldrons at the abandoned Dutch settlement of Smeerenburg in Svalbard, Norway This article is about the body tissue. ... For other uses, see Fur (disambiguation). ... Countercurrent exchange is a mechanism used to transfer some component of a fluid from one flowing current of fluid to another across a permeable barrier between them. ... For other uses, see Adaptation (disambiguation). ... This article is about the animal. ...


Research

Considerable research has been conducted on the incidence of diseases that afflict marine mammals in the marine environment. This work has addressed leptospirosis, phocine herpesvirus, neurological diseases and other pathologies affecting marine mammals. Entire research organizations have developed such as the Marine Mammal Center to focus upon the rehabilitation and research functions of marine mammals. Genera Subfamily Alphaherpesvirinae    Simplexvirus    Varicellovirus    Mardivirus    Iltovirus Subfamily Betaherpesvirinae    Cytomegalovirus    Muromegalovirus    Roseolovirus Subfamily Gammaherpesvirinae    Lymphocryptovirus    Rhadinovirus Unassigned    Ictalurivirus The Herpesviridae are a family of DNA viruses that cause diseases in humans and animals. ... Neurology is a branch of medicine dealing with disorders of the central and peripheral nervous systems. ... Release of rehabilitated pinnipeds into the Pacific Ocean The Marine Mammal Center is a private non-profit organization centered on rescue, rehabilitation, environmental research and education pertaining to certain species within the pinnipedia, carnivora and cetacea biological orders. ...


External links

  • Read Congressional Research Service (CRS) Reports regarding Marine mammals
  • A 2005 Report by the National Academy of Sciences entitled Marine Mammal Populations and Ocean Noise, is available for free online reading and research
  • University of Washington Libraries Digital Collections -- Freshwater and Marine Image Bank -- Aquatic Mammals An ongoing digital collection of images related to marine and aquatic mammals.
  • Marine Mammal Resource

  Results from FactBites:
 
Marine mammal - Wikipedia, the free encyclopedia (483 words)
A marine mammal is a mammal that is primarily ocean-dwelling or depends on the ocean for its food.
Since different groups of marine mammals originate from different ancestors, this is a case of convergent evolution.
Since mammals originally evolved on land, their spines are optimized for running, allowing for up-and-down but only little sideways motion.
SMM STRATEGIES FOR PURSUING A CAREER IN MARINE MAMMAL SCIENCE (3759 words)
Marine mammal scientists try to understand these animals' genetic, systematic, and evolutionary relationships; population structure; community dynamics; anatomy and physiology; behavior and sensory abilities; parasites and diseases; geographic and microhabitat distributions; ecology; management; and conservation.
Marine mammal scientists are hired because of their skills as scientists, not because they like or want to work with marine mammals.
Marine mammal studies often involve long, hard, soggy, sunburned days at sea, countless hours in a laboratory, extensive work on computers, hard labor such as hauling buckets of fish to feed animals, hours of cleanup, numerous reports, tedious grant applications and permit applications.
  More results at FactBites »

 
 

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