NationMaster - Encyclopedia: Manatee

Manatees (family.. Trichechidae, genus Trichechus) are large, fully aquatic marine mammals sometimes known as sea cows. The name manatí comes from the Taino which are the original peoples of the Caribbean, meaning "breast". They comprise three of the four living species in the order Sirenia, the other being the dugong, which is native to the Eastern Hemisphere. The Sirenia is thought to have evolved from four-legged land mammals over 60 million years ago, with the closest living relatives being the Proboscidea (elephants) and Hyracoidea (hyraxes).^[1] The hierarchy of scientific classification In biological classification, family (Latin: familia, plural familiae) is a rank, or a taxon in that rank. ... For other uses, see Genus (disambiguation). ... A Humpback whale (Megaptera novaeangliae), a member of Order Cetacea A Leopard seal (Hydrurga leptonyx), a member of infrafamily Pinnipedia A West Indian Manatee (Trichechus manatus), a member of Order Sirenia A pair of Sea Otters (Enhydra lutris), a member of family Mustelidae A Polar bear (Ursus maritimus), a member... 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. ... Binomial name (MÃ¼ller, 1776) Natural range of . ... The eastern hemisphere of Earth, highlighted in yellow. ... Groups Jozaria (extinct) Anthracobunidae (extinct) Moeritheriidae (extinct) Euproboscidea Numidotheriidae (extinct) Barytheriidae (extinct) Deinotheriidae (extinct) Elephantiformes Phiomiidae (extinct) Palaeomastodontidae (extinct) Hemimastodontidae (extinct) Euelephantoidea Choerolophodontidae (extinct) Amebelodontidae (extinct) Gnathabelodontidae (extinct) Gomphotheriidae (extinct) Elephantidae Mammutidae (extinct) Proboscidea is an order containing only one family of living animals, Elephantidae, the elephants, with three species... Genera Procavia Heterohyrax Dendrohyrax A hyrax is any of about 11 species of fairly small, thickset, herbivorous mammals in the order Hyracoidea. ...

Physical characteristics

The manatees differ from the dugong. Dugongs have a forked tail, similar in shape to a whale's, while manatees' tails are paddle-shaped. They are mainly herbivores, spending most of their time grazing in shallow waters and at depths of 1-2 metres (3-7 ft). Much of the knowledge about manatees is based upon research done in Florida and cannot necessarily be attributed to all types of manatees. Generally, manatees have a mean mass of 400-550 kg (900-1200 lb), and mean length of 2.8-3.0 m (9-10 ft), with maximums of 3.6 meters and 1,775 kg seen (the females tend to be larger and heavier). When born, baby manatees have an average mass of 30 kg. Binomial name (MÃ¼ller, 1776) Natural range of . ... Binomial name (MÃ¼ller, 1776) Natural range of . ... A deer and two fawns feeding on some foliage A herbivore is often defined as any organism that eats only plants[1]. By that definition, many fungi, some bacteria, many animals, about 1% of flowering plants and some protists can be considered herbivores. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, â€² â€“ a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Look up pound in Wiktionary, the free dictionary. ...

On average, most manatees swim at about 5 km/h to 8 km/h (1.4 m/s to 2.2 m/s; 3 to 5 miles per hour). However, they have been known to swim up to 30 km/h (8 m/s; 20 miles per hour) in short bursts. Manatees inhabit the shallow, marshy coastal areas and rivers of the Caribbean Sea and the Gulf of Mexico (T. manatus, West Indian manatee), the Amazon basin (T. inunguis, Amazonian manatee), and West Africa (T. senegalensis, West African manatee). A fourth species, the dwarf manatee (T. bernhardi) was recently proposed for a population found in the Brazilian Amazon,^[2] although some have questioned its validity, instead believing it is an immature Amazonian manatee.^[3] Florida is usually the northernmost range of the West Indian manatee as their low metabolic rate makes cold weather endurance difficult. They may on occasion stray up the mid-Atlantic coast in summer. Half a manatee's day is spent sleeping in the water, surfacing for air regularly at intervals no greater than 20 minutes. â€œMilesâ€ redirects here. ... This article is about marsh, a type of wetland. ... Map of Central America and the Caribbean The Caribbean Sea (pronounced or ) is a tropical sea in the Western Hemisphere, part of the Atlantic Ocean, southeast of the Gulf of Mexico. ... Gulf of Mexico in 3D perspective. ... Binomial name Trichechus manatus Linnaeus, 1758 A group of three West Indian manatees. ... Amazon River basin The Amazon Basin is the part of South America drained by the Amazon River and its tributaries. ... Binomial name Trichechus inunguis (Natterer, 1883) The Amazonian Manatee Trichechus inunguis is a species of manatee that lives in the freshwater habitats of the Amazon River and its tributaries. ... Western Africa (UN subregion) Maghreb[1] West Africa or Western Africa is the westernmost region of the African continent. ... Binomial name Trichechus senegalensis Link, 1795 The West African Manatee Trichechus senegalensis is a species of manatee, and is the least studied of the sirenians. ...

Florida manatees (T. m. latirostris) have been known to live up to 60 years, and they can move freely between different salinity extremes; however, Amazonian manatees (T. inunguis) never venture out into salt water. They have a large flexible prehensile upper lip that acts in many ways like a shortened trunk, somewhat similar to an elephant's. They use the lip to gather food and eat, as well as using it for social interactions and communications. Their small, widely spaced eyes have eyelids that close in a circular manner. Manatees are also believed to have the ability to see in color. Annual mean sea surface salinity for the World Ocean. ... Prehensility is the quality of an organ that has adapted for grasping or holding. ...

They emit a wide range of sounds used in communication, especially between cows and their calves, yet also between adults to maintain contact and during sexual and play behaviors. They may use taste and smell, in addition to sight, sound, and touch, to communicate. Manatees are capable of understanding discrimination tasks, and show signs of complex associated learning and advanced long term memory.^[4] They demonstrate complex discrimination and task-learning similar to dolphins and pinnipeds in acoustic and visual studies.^[5] This article is about the dolphin mammal. ... subfamilies Otariidae Phocidae Odobenidae Pinnipeds are large marine mammals belonging to the Pinnipedia, a family (sometimes a suborder or superfamily, depending on the classification scheme) of the order Carnivora. ... Acoustics is the interdisciplinary sciences that always deals with the study of sound, ultrasound and infrasound (all mechanical waves in gases, liquids, and solids). ...

Manatees typically breed only once every other year, since gestation lasts about 12 months, and it takes a further 12 to 18 months to wean the calf. Only a single calf is born at a time and aside from mothers with their young or males following a receptive female, manatees are generally solitary creatures.^[6] Gestation is the carrying of an embryo or fetus inside a female viviparous animal. ... A breastfeeding infant Breastfeeding is the practice of a woman feeding an infant (or sometimes a toddler or a young child) with milk produced from her mammary glands, usually directly from the nipples. ...

Diet

Manatees are herbivores and eat over 60 different plant species such as mangrove leaves, turtle grass, and types of algae, using their divided upper lip. An adult manatee will commonly eat up to 9% of its body weight (approx 50 kg) per day. Manatees have been known to eat small amounts of fish from nets.^[7] A deer and two fawns feeding on some foliage A herbivore is often defined as any organism that eats only plants[1]. By that definition, many fungi, some bacteria, many animals, about 1% of flowering plants and some protists can be considered herbivores. ... Above and below water view at the edge of the mangal. ...

Like horses, they have a simple stomach, but a large cecum, in which they can digest tough plant matter. In general, their intestines are unusually long for animals of their size. The adults have no incisor or canine teeth, just a set of cheek teeth, which are not clearly differentiated into molars and premolars. Uniquely among mammals, these teeth are continuously replaced throughout life; with new teeth growing at the rear as older teeth fall out from further forward in the mouth. At any given time, a manatee typically has no more than six teeth.^[6] Binomial name Equus caballus Linnaeus, 1758 The horse (Equus caballus, sometimes seen as a subspecies of the Wild Horse, Equus ferus caballus) is a large odd-toed ungulate mammal, one of ten modern species of the genus Equus. ... The cecum or caecum (from the Latin caecus meaning blind) is a pouch connected to the ascending colon of the large intestine and the ileum. ... Incisors (from Latin incidere, to cut) are the first kind of tooth in heterodont mammals. ... This article or section may be confusing or unclear for some readers, and should be edited to rectify this. ... Molars are the rearmost and most complicated kind of tooth in most mammals. ... The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. ...

Population

The population of manatees in Florida (T. manatus) is thought to be between 1,000 and 3,000, yet population estimates are very difficult. Manatees are more distantly related to elephants and hyraxes; the latter are small mammals native to Asia and Africa. Manatees are native to Florida. The number of manatee deaths in Florida caused by humans has been increasing through the years, and now typically accounts for 20%-40% of recorded manatee deaths.^[8] In 2006 there were near 300 registered and confirmed manatees in Florida killed by human activity, the majority of these, that happened to be discovered by Florida Fish and Wildlife, have been caused by boat strikes. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

Accurate population estimates of the Florida manatee are notoriously difficult and have been called scientifically weak, with widely varying counts from year to year, some areas showing possible increases yet others with decreases, but with very little strong evidence of increases except in 2 areas. However, population viability analysis studies carried out in 1997, found that decreasing adult survival and eventual extinction is a probable future outcome for the Florida manatees, unless they are aggressively protected.^[9] Manatee counts are highly variable without an accurate way to estimate numbers,^[10] for example, in Florida in 1996, a winter survey found 2,639 manatees, in 1997 a January survey found 2,229, but then a February survey found 1,709.^[5] Fossil remains of manatee ancestors show they have inhabited Florida for about 45 million years. Population viability analysis is a branch of conservation biology dealing with techniques for determining the genetic diversity, spatial and temporal features of a population so as to evaluate the risk of extinction for that population. ...

The Amazonian Manatee (T. inunguis) is a species of manatee that lives in the freshwater habitats of the Amazon River and its tributaries. Their color is brownish gray and they have thick, wrinkled skin, often with coarse hair, or "whiskers." Its main predator is also man.

The African Manatee (T. senegalensis) is the least studied of the three species of manatees. Photos of African Manatees are very rare; although very little is known about this species, scientists think they are similar to the West Indian Manatees. They are found in coastal marine and estuarine habitats, and in fresh water river systems along the west coast of Africa from the Senegal River south to the Kwanza River in Angola, including areas in Gambia, Liberia, Guinea-Bissau, Guinea, Sierra Leone, Côte d'Ivoire, Ghana, Mali, Nigeria, Cameroon, Gabon, Republic of the Congo, and Democratic Republic of the Congo. Although crocodiles and sharks occasionally kill manatees in Africa, their only significant threats are from humankind, such as poaching, habitat loss, and other environmental impacts. They live as high upriver on the Niger as Gao, Mali. Although rare, they occasionally get stranded as the river dries up at the end of rainy season and are cooked for a meal. The name in Sonrai, the local language, is "ayyu".

Habitat

Manatees typically inhabit warm, shallow, coastal estuarine waters and cannot survive below 15°C (288 K; 60°F). Their natural source for warm waters during the winter is warm-spring fed rivers. The West Indian Manatee migrates into Florida rivers such as the Crystal River, the Homosassa River and the Chassawohitzka River. The head springs of these rivers maintain a water temperature of 22°C (299 K; 72°F) year round. During the winter months, November to March, approximately 400 West Indian Manatees (According to the National Wildlife Refuge Service) congregate in the rivers in Citrus County, Florida. Image File history File links File links The following pages link to this file: Sirenia ... Image File history File links File links The following pages link to this file: Sirenia ... The Crystal River is a very short river in Citrus County, Florida flowing into the Gulf of Mexico. ... Citrus County is a county located in the U.S. state of Florida. ...

Manatees have been spotted as far north as Cape Cod, and as recently as the late summer of 2006, one made it up to New York City and Rhode Island's Narragansett Bay, as cited by the Boston Globe. According to Memphis, Tennessee's Commercial Appeal newspaper, one manatee was spotted in the Wolf River harbor near the Mississippi River in downtown Memphis, Tennessee, on October 23, 2006, though it was later found dead ten miles downriver in McKellar Lake.^[11] This article is about the area of Massachusetts known as Cape Cod. For other uses, see Cape Cod (disambiguation). ... This article is about the U.S. State. ... Narragansett Bay, shown in pink. ... The Boston Globe is the most widely-circulated daily newspaper in Boston, Massachusetts and in the greater New England region. ... For other uses, see Memphis (disambiguation). ... The Commercial Appeal is the predominant daily newspaper of Memphis, Tennessee. ... Wolf River may refer to: Rivers in the united States: The Wolf River in Kansas The Wolf River in Tennessee The Wolf River in Wisconsin Towns in the United States: Wolf River, Langlade County, Wisconsin Wolf River, Winnebago County, Wisconsin This is a disambiguation page — a navigational aid which lists... For the river in Canada, see Mississippi River (Ontario). ... For other uses, see Memphis (disambiguation). ... is the 296th day of the year (297th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...

Manatees often congregate near power plants, which warm the waters. Some have become reliant on this source of artificial heat and have ceased migrating to warmer waters. Some power plants have recently been closing and the U.S. Fish and Wildlife Service is trying to find a new way to heat the water for these manatees. The main water treatment plant in Guyana has four manatees that keep storage canals clear of weeds.

Studies in Florida suggest that Florida manatees must have some access to fresh water for proper osmoregulation. Osmoregulation is the active regulation of the osmotic pressure of bodily fluids to maintain the homeostasis of the bodys water content; that is it keeps the bodys fluids from becoming too dilute or too concentrated. ...

Captivity

The oldest manatee in captivity is Snooty who is held at the South Florida Museum. He was born at the Miami Seaquarium on July 21, 1948 and came to the South Florida Museum in Bradenton, Florida in 1949. Snooty is a manatee that resides at the South Florida Museums Parker Manatee Aquarium in Bradenton, Florida. ... The South Florida Museum, located in Bradenton, Florida, is a museum specializing in the natural and cultural history of Floridas gulf coast. ... is the 202nd day of the year (203rd in leap years) in the Gregorian calendar. ... Year 1948 (MCMXLVIII) was a leap year starting on Thursday (link will display the 1948 calendar) of the Gregorian calendar. ... Bradenton is a city in Manatee County, Florida, United States. ...

Vulnerability

Although manatees have few natural predators (sharks, crocodiles, orcas and alligators), all three species of manatee are listed by the World Conservation Union as vulnerable to extinction. The current main threat to manatees in the United States is being struck with boats or slashed with propellers. Sometimes manatees can live through strikes, and over fifty deep slashes and permanent scars have been observed on some manatees off the Florida coast.^[5] However, the wounds are often fatal, and the lungs may even pop out through the chest cavity.^[5] It is illegal under federal and Florida law to cause the manatees injury or harm.^[5] Image File history File links Download high resolution version (480x640, 114 KB)Picture of Jonathan Witte. ... Image File history File links Download high resolution version (480x640, 114 KB)Picture of Jonathan Witte. ... The World Conservation Union or International Union for the Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource conservation. ...

According to marine mammal veterinarians, "The severity of mutilations for some of these individuals can be astounding - including long term survivors with completely severed tails, major tail mutilations, and multiple disfiguring dorsal lacerations. These injuries not only cause gruesome wounds, but may also impact population processes by reducing calf production (and survival) in wounded females - observations also speak to the likely pain and suffering endured".^[5] In an example, they cited one case study of a small calf "with a severe dorsal mutilation trailing a decomposing piece of dermis and muscle as it continued to accompany and nurse from its mother...by age 2 its dorsum was grossly deformed and included a large protruding rib fragment visible."^[5] These veterinarians go on to state that "the overwhelming documentation of gruesome wounding of manatees leaves no room for denial. Minimization of this injury is explicit in the Recovery Plan, several state statutes, and federal laws, and implicit in our society's ethical and moral standards."^[5] In American and Canadian English, a veterinarian (from Latin veterinae, draught animals) is an animal doctor, a practitioner of veterinary medicine. ...

Manatees occasionally ingest fishing gear (hooks, metal weights, etc.) while feeding. These foreign materials do not seem to harm manatees, except for monofilament line or string. This can clog the animal's digestive system and slowly kill the animal. Look up kayak in Wiktionary, the free dictionary. ... Monofilament line is a thin string made from a single fiber. ...

Manatees can also be crushed in water control structures (navigation locks, flood gates, etc.), drown in pipes and culverts, and are occasionally killed from entanglement in fishing gear, primarily crab pot float lines. Manatees are also vulnerable to red tides—blooms of algae which leach oxygen from the water. Tokyo floodgates to protect from typhoon surges. ... A culvert is a flowing body of water which passes underneath a road, railway, or embankment, or the part thereof that does so. ... A red tide off the coast of La Jolla, California. ... An algal bloom is a relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic system. ... For the programming language, see algae (programming language). ...

Manatees were commonly hunted for their meat by natives of the Caribbean, although this is much less common today.^[12] West Indies redirects here. ...

On June 8, 2006, The Florida Fish and Wildlife Conservation Commission voted to reclassify the manatee on Florida's list, to a "threatened" status in that state.^[13] While none of the state laws protecting manatees have changed, many wildlife conservationists are not pleased with the removal decision. Manatees remain classified as "endangered" at the federal level. is the 159th day of the year (160th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...

While humans are allowed to swim with manatees in one area of Florida,^[14] there have been numerous charges of people harassing and disturbing the manatees in various ways, in addition to the concern about repeated motorboat strikes causing the maiming, disfiguring, and death of manatees all across the Florida coast, and this privilege of swimming with wild manatees may be soon repealed.^[15]

Hunting

Manatees were traditionally hunted by indigenous Caribbean people. When Christopher Columbus arrived in the region, manatee hunting was an established trade. Native Americans hunted manatees to make war shields, canoes, and shoes, though the manatee was predominantly hunted for its abundant meat. The primary method of hunting the manatee was somewhat crude, as the hunter would use dugout canoes to approach targeted manatees. The indigenous hunter would then use various methods of baiting in order to attract a manatee close enough to hit the animal near the head with an oar-like pole, temporarily stunning the manatee. Many times the creature would flip over, leaving it vulnerable to further attacks. Download high resolution version (850x607, 87 KB)From http://www-pao. ... Download high resolution version (850x607, 87 KB)From http://www-pao. ... Christopher Columbus (1451 â€“ May 20, 1506) was a navigator, colonizer, and explorer and one of the first Europeans to explore the Americas after the Vikings. ... This article is about the people indigenous to the United States. ... This article is about the defensive device. ... Canoe at El Nido, Philippines A canoe is a relatively small human-powered boat. ... shoe for right foot A shoe is a piece of footwear for humans, less than a boot and more than a slipper. ...

Manatees were also hunted for their valuable bones, which were used to make "Special Potions." Up until the 1800s, museums paid as much as $100 for manatee bones or hides. Though hunting manatees was banned in 1893, poaching continues today.

Disposition and boat collisions

Manatees are slow-moving, non-aggressive, and generally curious creatures. They enjoy warmer waters and are known to congregate in shallow waters, and frequently migrate through brackish water estuaries to freshwater springs. Image File history File links Nowake. ... Image File history File links Nowake. ... Brackish redirects here. ... For other meanings, see Estuary (disambiguation) RÃo de la Plata estuary An estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. ... Fresh water redirects here. ... A natural spring on Mackinac Island in Michigan. ...

Their slow-moving, curious nature, coupled with dense coastal development, has led to a number of violent collisions with propellers from fast moving recreational motor boats, leading frequently to maiming, disfigurement, and even death. As a result, a large portion of manatees exhibit propeller scars on their backs and they are now even classed by humans from their scar patterns. Some are concerned that the current situation is inhumane, with sometimes upwards of 50 scars and disfigurations from boat strikes on a single manatee.^[5]^[16] Often the cuts lead to infections, which can prove fatal. Internal injuries stemming from hull impacts have also been fatal. For other uses, see Propeller (disambiguation). ...

In 2003, a population model was released by the U.S. Geological Survey that predicted an extremely grave situation confronting the manatee in both the Southwest and Atlantic regions where the vast majority of manatees are found. It states, “In the absence of any new management action, that is, if boat mortality rates continue to increase at the rates observed since 1992, the situation in the Atlantic and Southwest regions is dire, with no chance of meeting recovery criteria within 100 years.”^[17]

In 2007, a University of Florida study found that more than half of boat drivers in Volusia County, Florida sped through marked conservation zones despite their professed support for the endangered animals, and little difference was found between the driving speeds of ski boats, pontoons and fishing vessels. In the study, 84 percent of the 236 people who responded said they fully obeyed with speed limits in manatee zones during their most recent boating experience, but observers found that only 45 percent actually complied. "Hurricanes, cold stress, red tide poisoning and a variety of other maladies threaten manatees, but by far their greatest danger is from watercraft strikes, which account for about a quarter of Florida manatee deaths," said study curator John Jett.^[18] The University of Florida (Florida or UF) is a flagship public land-grant, sea-grant[3] major research university located on a 2,000 acre campus in Gainesville, Florida, United States of America. ... Volusia redirects here. ...

Cultural depictions

The manatee has been linked to folklore on mermaids. Native Americans ground the bones to treat asthma and earache. In West African folklore, it was sacred and thought to have been once human. Killing one was taboo and required penance.^[19] For other uses, see Mermaid (disambiguation). ...

Contents

Physical characteristics

Diet

Population

Habitat

Captivity

Vulnerability

Hunting

Disposition and boat collisions

Cultural depictions

See also

Notes

References

External links

Contents

Physical characteristics GA_googleFillSlot("encyclopedia_square");

Diet

Population

Habitat

Captivity

Vulnerability

Hunting

Disposition and boat collisions

Cultural depictions

See also

Notes

References

External links

Physical characteristics