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54-534: Manatees ( / ˈ m æ n ə t iː z / , family Trichechidae , genus Trichechus ) are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows . There are three accepted living species of Trichechidae, representing three of the four living species in the order Sirenia : the Amazonian manatee ( Trichechus inunguis ), the West Indian manatee ( Trichechus manatus ), and

108-431: A characteristic that was used to make early links between the manatee and elephants. The lids of manatees' small, widely spaced eyes close in a circular manner. The manatee has a large, flexible, prehensile upper lip, used to gather food and eat and for social interaction and communication. Manatees have shorter snouts than their fellow sirenians , the dugongs . Manatee adults have no incisor or canine teeth, just

162-457: A consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called the seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time

216-446: A family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching

270-501: A quarter of Florida manatee deaths," said study curator John Jett. 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

324-541: A red tide killed 123 manatees between November 2022 and June 2023. In 2021 a massive die-off of seagrass along the Atlantic coast of Florida left manatees without enough food to eat. As a result of this ecological disaster Florida's manatees began dying at an alarming rate, largely from starvation . In early 2022 the U.S. Fish and Wildlife Service began a feeding program to address the situation by distributing 3,000 pounds (1,361 kg) of lettuce per day to save

378-462: A relatively large cecum. In many species, it is considerably wider than the colon. For some herbivores such as lagomorphs (rabbits, hares, pikas), easily digestible food is processed in the gastrointestinal tract and expelled as regular feces. But in order to get nutrients out of hard to digest fiber, lagomorphs ferment fiber in the cecum and then expel the contents as cecotropes , which are reingested (cecotrophy). The cecotropes are then absorbed in

432-407: A result, a large proportion of manatees exhibit spiral cutting propeller scars on their backs, usually caused by larger vessels that do not have skegs in front of the propellers like the smaller outboard and inboard-outboard recreational boats have. They are now even identified by humans based on their scar patterns. Many manatees have been cut in two by large vessels like ships and tug boats, even in

486-402: A set of cheek teeth, which are not clearly differentiated into molars and premolars . These teeth are repeatedly replaced throughout life , with new teeth growing at the rear as older teeth fall out from farther forward in the mouth, somewhat as elephants ' teeth do. At any time, a manatee typically has no more than six teeth in each jaw of its mouth. The manatee's tail is paddle-shaped, and

540-526: A simple stomach, but a large cecum , in which it can digest tough plant matter. Generally, the intestines are about 45 meters, unusually long for an animal of the manatee's size. Fossil remains of manatee ancestors - also known as sirenians - date back to the Early Eocene . It is thought that they reached the isolated area of the South American continent and became known as Trichechidae . In

594-1073: A single calf is born. Gestation lasts about 12 months and to wean the calf takes a further 12 to 18 months, although females may have more than one estrous cycle per year. Manatees emit a wide range of sounds used in communication, especially between cows and their calves. Their ears are large internally but the external openings are small, and they are located four inches behind each eye. Adults communicate to maintain contact and during sexual and play behaviors. Taste and smell, in addition to sight, sound, and touch, may also be forms of communication. Manatees are herbivores and eat over 60 different freshwater (e.g., floating hyacinth, pickerel weed , alligator weed , water lettuce , hydrilla , water celery, musk grass , mangrove leaves) and saltwater plants (e.g., sea grasses, shoal grass , manatee grass , turtle grass , widgeon grass , sea clover, and marine algae). Using their divided upper lip, an adult manatee will commonly eat up to 10%–15% of their body weight (about 50 kg) per day. Consuming such an amount requires

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648-582: A term used for the proliferation, or "blooms", of the microscopic marine algae Karenia brevis . This dinoflagellate produces brevetoxins that can have toxic effects on the central nervous system of animals. In 1996, a red tide was responsible for 151 manatee deaths in Florida. The bloom was present from early March to the end of April and killed approximately 15% of the known population of manatees along South Florida's western coast. Other blooms in 1982 and 2005 resulted in 37 and 44 deaths respectively, and

702-779: A winter survey found 2,639 manatees; in 1997, a January survey found 2,229, and a February survey found 1,706. A statewide synoptic survey in January 2010 found 5,067 manatees living in Florida, the highest number recorded to that time. As of January 2016, the USFWS estimates the range-wide West Indian manatee population to be at least 13,000; as of January 2018, at least 6,100 are estimated to be in Florida. Population viability studies conducted in 1997 found that decreasing adult survival and eventual extinction were probable future outcomes for Florida manatees unless they received more protection. The U.S. Fish and Wildlife Service proposed downgrading

756-510: Is explicit in the Recovery Plan, several state statutes, and federal laws, and implicit in our society's ethical and moral standards. One quarter of annual manatee deaths in Florida are caused by boat collisions with manatees. In 2009, of the 429 Florida manatees recorded dead, 97 were killed by commercial and recreational vessels, which broke the earlier record number of 95 set in 2002. Another cause of manatee deaths are red tides ,

810-695: Is also the smallest. Since they are unable to reduce peripheral heat loss, it is found primarily in tropical waters. They are found in coastal marine and estuarine habitats, and in freshwater river systems along the west coast of Africa from the Senegal River south to the Cuanza River in Angola . They live as far upriver on the Niger River as Koulikoro in Mali , 2,000 km (1,200 mi) from

864-402: Is an end point for the colon with a dead-end portion terminating with the appendix . The connection between the end of the small intestine (ileum) and the start (as viewed from the perspective of food being processed) of the colon (cecum) is now clearly understood, and is called the ileocecal orifice. The connection between the end of the cecum and the beginning of the ascending colon is called

918-403: Is involved in absorption of salts and electrolytes and lubricates the solid waste that passes into the large intestine. The cecum and appendix are derived from the bud of cecum that forms during week 6 in the midgut next to the apex of the umbilical herniation. Specifically, the cecum and appendix are formed by the enlargement of the postarterial segment of the midgut loop. The proximal part of

972-698: Is not available for an extended period of time. Manatees can travel hundreds of miles annually, and have been seen as far north as Cape Cod , and in 1995 and again in 2006, one was seen in New York City and Rhode Island 's Narragansett Bay . A manatee was spotted in the Wolf River harbor near the Mississippi River in downtown Memphis in 2006, and was later found dead 16 km (10 mi) downriver in McKellar Lake. Another manatee

1026-407: Is the clearest visible difference between manatees and dugongs; a dugong tail is fluked, similar in shape to that of a whale. The manatee is unusual among mammals in having just six cervical vertebrae , a number that may be due to mutations in the homeotic genes . All other mammals have seven cervical vertebrae, other than the two-toed and three-toed sloths . Like the horse , the manatee has

1080-521: Is warm, spring-fed rivers. The coast of the state of Georgia is usually the northernmost range of the West Indian manatees because their low metabolic rate does not protect them in cold water. Prolonged exposure to water below 20 °C (68 °F) can cause "cold stress syndrome" and death. West Indian manatees can move freely between fresh water and salt water. However, studies suggest that they are susceptible to dehydration if freshwater

1134-476: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Cecum It receives chyme from the ileum , and connects to

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1188-562: The Late Miocene , trichechids were likely restricted in South American coastal rivers and they fed on many freshwater plants. Dugongs inhabited the West Atlantic and Caribbean waters and fed on seagrass meadows instead. As the sea grasses began to grow, manatees adapted to the changing environment by growing supernumerary molars. Sea levels lowered and increased erosion and silt runoff was caused by glaciation . This increased

1242-1068: The West African manatee ( Trichechus senegalensis ). They measure up to 4.0 metres (13 ft 1 in) long, weigh as much as 590 kilograms (1,300 lb), and have paddle-like tails. Manatees are herbivores and eat over 60 different freshwater and saltwater plants. Manatees inhabit the shallow, marshy coastal areas and rivers of the Caribbean Sea , the Gulf of Mexico , the Amazon basin , and West Africa . The main causes of death for manatees are human-related issues, such as habitat destruction and human objects. Their slow-moving, curious nature has led to violent collisions with propeller-driven boats and ships. Some manatees have been found with over 50 scars on them from propeller blades. Natural causes of death include adverse temperatures, predation by crocodiles on young, and disease. The etymology of

1296-404: The ascending colon of the large intestine . It is separated from the ileum by the ileocecal valve (ICV) or Bauhin's valve. It is also separated from the colon by the cecocolic junction. While the cecum is usually intraperitoneal, the ascending colon is retroperitoneal . In herbivores , the cecum stores food material where bacteria are able to break down the cellulose. In humans, the cecum

1350-489: 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. "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

1404-693: The anterior teeth abrade. Some studies indicate that the rate is about 1 cm/month although other studies indicate 0.1 cm/month. 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 ). West Indian manatees prefer warmer temperatures and are known to congregate in shallow waters. They frequently migrate through brackish water estuaries to freshwater springs . They cannot survive below 15 °C (60 °F). Their natural source for warmth during winter

1458-514: The book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,

1512-491: The bud grows rapidly to form the cecum. The lateral wall of the cecum grows much more rapidly than the medial wall, with the result that the point of attachment of the appendix comes to lie on the medial side. The cecum's position changes after the midgut rotates and the ascending colon elongates, and the accumulation of meconium inside the cecum may result in the latter's increased diameter. The term cecum comes from Latin (intestinum) caecum , literally 'blind intestine', in

1566-399: The cecocolic orifice. A cecal carcinoid tumor is a carcinoid tumor of the cecum. An appendiceal carcinoid tumor (a carcinoid tumor of the appendix) is sometimes found next to a cecal carcinoid. Neutropenic enterocolitis (typhlitis) is the condition of inflammation of the cecum, primarily caused by bacterial infections. Over 99% of the bacteria in the gut are anaerobes , but in

1620-422: The cecum, aerobic bacteria reach high densities. A cecum is present in most amniote species, and also in lungfish , but not in any living species of amphibian . In reptiles , it is usually a single median structure, arising from the dorsal side of the large intestine. Birds typically have two paired ceca, as do, unlike other mammals, hyraxes . Parrots do not have ceca. Most mammalian herbivores have

1674-567: The closest living relatives being the Proboscidea ( elephants ) and Hyracoidea ( hyraxes ). Manatees weigh 400 to 550 kg (880 to 1,210 lb), and average 2.8 to 3.0 m (9 ft 2 in to 9 ft 10 in) in length, sometimes growing to 4.6 m (15 ft 1 in) and 1,775 kg (3,913 lb) and females tend to be larger and heavier than males. At birth, baby manatees weigh about 30 kg (66 lb) each. The female manatee has two teats, one under each flipper,

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1728-781: The coast. In relation to the threat posed by humans, predation does not present a significant threat to manatees. When threatened, the manatee's response is to dive as deeply as it can, suggesting that threats have most frequently come from land dwellers such as humans rather than from other water-dwelling creatures such as caimans or sharks. The main causes of death for manatees are human-related issues, such as habitat destruction and human objects. Natural causes of death include adverse temperatures, predation by crocodiles on young, and disease. Their slow-moving, curious nature, coupled with dense coastal development, has led to many violent collisions with propeller-driven boats and ships, leading frequently to maiming, disfigurement, and even death. As

1782-597: The discovery with a 12-minute film that is available on the interactive streaming platform WaterBear. The discovery got picked up by the New Scientist in 2024, who featured in a 10-minute short film. The freshwater Amazonian manatee ( T. inunguis ) inhabits the Central Amazon Basin in Brazil , eastern Perú , southeastern Colombia , but not Ecuador . It is the only exclusively freshwater manatee, and

1836-435: The enamel structure in manatee molars is weak. To compensate for this, manatee teeth are continually replaced. When anterior molars wear down, they are shed. Posterior molars erupt at the back of the row and slowly move forward to replace these like enamel crowns on a conveyor belt, similarly to elephants . This process continues throughout the manatee's lifetime. The rate at which the teeth migrate forward depends on how quickly

1890-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and

1944-409: The flippers are used to scoop the vegetation toward the manatee's lips. The manatee has prehensile lips; the upper lip pad is split into left and right sides which can move independently. The lips use seven muscles to manipulate and tear at plants. Manatees use their lips and front flippers to move the plants into the mouth. The manatee does not have front teeth, however, behind the lips, on the roof of

1998-530: The frequency the boat makes. However, a manatee may not be able to hear the approaching boats when they are performing day-to-day activities or distractions. The manatee has a tested frequency range of 8 to 32 kilohertz. Manatees hear on a higher frequency than would be expected for such large marine mammals. Many large boats emit very low frequencies, which confuse the manatee and explain their lack of awareness around boats. The Lloyd's mirror effect results in low frequency propeller sounds not being discernible near

2052-483: The highly populated lower St. Johns River's narrow channels. Some are concerned that the current situation is inhumane, with upwards of 50 scars and disfigurements from vessel strikes on a single manatee. Often, the lacerations lead to infections, which can prove fatal. Internal injuries stemming from being trapped between hulls and docks and impacts have also been fatal. Recent testing shows that manatees may be able to hear speed boats and other watercraft approaching, due to

2106-498: The likely pain and suffering endured. 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." These veterinarians go on to state: [T]he overwhelming documentation of gruesome wounding of manatees leaves no room for denial. Minimization of this injury

2160-399: The malnourished animals. Manatees can also be crushed and isolated in water control structures ( navigation locks , floodgates , etc.) and are occasionally killed by entanglement in fishing gear, such as crab pot float lines, box traps, and shark nets. While humans are allowed to swim with manatees in one area of Florida, there have been numerous charges of people harassing and disturbing

2214-406: The manatee to graze for up to seven hours a day. To be able to cope with the high levels of cellulose in their plant based diet, manatees utilize hindgut fermentation to help with the digestion process. Manatees have been known to eat small numbers of fish from nets. Manatees use their flippers to "walk" along the bottom whilst they dig for plants and roots in the substrate. When plants are detected,

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2268-576: The manatee's status from endangered to threatened in January 2016 after more than 40 years. There is a small population of the subspecies Antillean manatee ( T. m. manatus ) found in Mexico's Caribbean coastal area. The best estimate for this population is 200-250. As of 2022, a new manatee habitat was discovered by Klaus Thymann within the cenotes of Sian Ka'an Biosphere Reserve on the Yucatán Peninsula . The explorer and his team documented

2322-632: The manatees. According to the United States Fish and Wildlife Service, approximately 99 manatee deaths each year are related to human activities. In January 2016, there were 43 manatee deaths in Florida alone. Family (biology) Family ( Latin : familia , pl. : familiae ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between

2376-427: The mouth, there are dense, ridged pads. These horny ridges, and the manatee's lower jaw, tear through ingested plant material. Manatees have four rows of teeth. There are 6 to 8 high-crowned, open-rooted molars located along each side of the upper and lower jaw giving a total of 24 to 32 flat, rough-textured teeth. Eating gritty vegetation abrades the teeth, particularly the enamel crown; however, research indicates that

2430-537: The name is unclear, with connections having been made to Latin manus "hand" and to Carib manaty "breast". The term sea cow is a reference to the species' slow, peaceful, herbivorous nature, reminiscent of that of bovines . Manatees are three of the four living species in the order Sirenia . The fourth is the Eastern Hemisphere 's dugong . The Sirenia are thought to have evolved from four-legged land mammals more than 60 million years ago, with

2484-491: The ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae , but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging

2538-417: The results were compared to human structures . The junction between the small intestine and the colon, called the ileocecal valve , is so small in some animals that it was not considered to be a connection between the small and large intestines. During a dissection, the colon could be traced from the rectum , to the sigmoid colon , through the descending , transverse , and ascending sections. The cecum

2592-883: The rivers in Citrus County, Florida such as the Crystal River National Wildlife Refuge . In winter, manatees often gather near the warm-water outflows of power plants along the Florida coast, instead of migrating south as they once did. Some conservationists are concerned that these manatees have become too reliant on these artificially warmed areas. Accurate population estimates of the West Indian manatee in Florida are difficult. They have been called scientifically weak because they vary widely from year to year, with most areas showing decreases, and little strong evidence of increases except in two areas. Manatee counts are highly variable without an accurate way to estimate numbers. In Florida in 1996,

2646-466: The sense 'blind gut' or ' cul de sac '. It is a direct translation from Ancient Greek τυφλὸν ( ἔντερον ) typhlòn ( énteron ). Thus the inflammation of the cecum is called typhlitis. In dissections by the Greek philosophers , the connection between the ileum of the small intestine and the cecum was not fully understood. Most of the studies of the digestive tract were done on animals and

2700-417: The small intestine to utilize the nutrients. In contrast, obligate carnivores , whose diets contain little or no plant matter, have a reduced cecum, which is often partially or wholly replaced by the appendix . Mammalian species which do not develop a cecum include raccoons , bears , and the red panda . Many fish have a number of small outpockets, called pyloric ceca , along their intestine; despite

2754-544: The surface, where most accidents occur. Research indicates that when a boat has a higher frequency the manatees rapidly swim away from danger. In 2003, a population model was released by the United States 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

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2808-1219: The tooth wear of the bottom-feeding manatees. Apart from mothers with their young, or males following a receptive female, manatees are generally solitary animals. Manatees spend approximately 50% of the day sleeping submerged, surfacing for air regularly at intervals of less than 20 minutes. The remainder of the time is mostly spent grazing in shallow waters at depths of 1–2 m (3 ft 3 in – 6 ft 7 in). The Florida subspecies ( T. m. latirostris ) has been known to live up to 60 years. Generally, manatees swim at about 5 to 8 km/h (3 to 5 mph). However, they have been known to swim at up to 30 km/h (20 mph) in short bursts. Manatees are capable of understanding discrimination tasks and show signs of complex associative learning . They also have good long-term memory . They demonstrate discrimination and task-learning abilities similar to dolphins and pinnipeds in acoustic and visual studies. Social interactions between manatees are highly complex and intricate, which may indicate higher intelligence than previously thought, although they remain poorly understood by science. Manatees typically breed once every two years; generally only

2862-712: Was found dead on a New Jersey beach in February 2020, considered especially unusual given the time of year. At the time of the manatee's discovery, the water temperature in the area was below 6.5 °C (43.7 °F). The West Indian manatee migrates into Florida rivers—such as the Crystal , the Homosassa , and the Chassahowitzka rivers, whose headsprings are 22 °C (72 °F) all year. Between November and March each year, about 600 West Indian manatees gather in

2916-488: Was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted the use of this term solely within

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