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Caribbean Monk Seal - Neomonachus tropicalis
Topic Started: Jan 8 2012, 02:33 PM (3,389 Views)
Taipan
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Caribbean Monk Seal - Neomonachus tropicalis

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Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Pinnipedia
Family: Phocidae
Genus: Neomonachus
Species: Neomonachus tropicalis

Conservation Status: Extinct

The Caribbean Monk Seal or West Indian Monk Seal (Neomonachus tropicalis) is an extinct species of seal. It is the only seal ever known to be native to the Caribbean sea and the Gulf of Mexico. The last verified recorded sighting occurred in 1952 at Serranilla Bank. On June 6, 2008, after five years of futile efforts to find or confirm sightings of any Caribbean monk seals, the U.S. government announced that the species is officially extinct and the only seal to vanish due to human causes.

A collection of Caribbean Monk Seal bones can be found at the Tropical Crane Point Hammock Museum in Key Vaca.

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Physical appearance

The Caribbean Monk Seal was a relatively large seal (1.8-2.7 m) with rolls of fat around its neck and brown pelage that faded to a yellow-white color on the stomach. The soles and palms were naked, with the nails on the anterior digits well developed. The males reached a length of about 3.25 meters and weighed up to 200 kilograms. Displaying sexual dimorphism, the females of this species were generally smaller than males.

Behavior and ecology

These pinnipeds lived in marine environment, spending much of their time in the water and occupying rocky and sandy coastlines for shelter and breeding. Their diet included lobsters, octopi, and reef fish.

Like other true seals, the Caribbean Monk Seal was sluggish on land. Its lack of fear for man and an unaggressive and curious nature also contributed to its demise.

Reproduction and longevity

Very little is known about the reproduction behavior and longevity of this animal. Live pups were likely born in early December because several females killed in the Yucatan during this time of the year had well-developed fetuses. It is believed that this animal's average lifespan was approximately twenty years.

History

During his 1494 voyage, Christopher Columbus described the Caribbean Monk Seal as a "sea-wolf." During that voyage, eight seals were killed for their meat. The region was soon colonized, and whatever habitat this species had was lost. People also began exploiting it commercially for its oil, and less frequently, for its meat. It became extinct in the 1950s from lack of food.

Sightings

In the United States, the last recorded sighting of this marine mammal occurred in 1932 off the Texas coast. The very last reliable records of this species are of a small colony at Serranilla Bank between Honduras and Jamaica in 1952.

Unconfirmed sightings of Caribbean Monk Seals by local fishermen and divers are relatively common in Haiti and Jamaica, but two recent scientific expeditions failed to find any sign of this animal. It is possible that the mammal still exists, but some biologists strongly believe that the sightings are of wandering Hooded Seals, which have been positively identified on archipelagos such as Puerto Rico and the Virgin Islands. On April 22, 2009, The History Channel aired an episode of Monster Quest which hypothesized that an unidentified sea creature videotaped in the Intracoastal Waterway of Florida's southeastern coast could possibly be the extinct Caribbean Monk Seal. No conclusive evidence has yet emerged in support of this contention, however, and opposing hypotheses asserted the creature was simply a misidentified, yet common to the area, West Indian Manatee.

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Edited by Taipan, May 15 2014, 01:06 PM.
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Taipan
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Extinct relative helps to reclassify the world's remaining two species of monk seal

Date: May 14, 2014
Source: Pensoft Publishers
Summary:
The recently extinct Caribbean monk seal was one of three species of monk seal in the world. Its relationship to the Mediterranean and Hawaiian monk seals, both living but endangered, has never been fully understood. Through DNA analysis and skull comparisons scientists have now clarified the Caribbean species' place on the seal family tree and created a completely new genus.

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This shows the recently extinct Caribbean monk seal, now classified as Neomonachus tropicalis.

The recently extinct Caribbean monk seal (Monachus tropicalis) was one of three species of monk seal in the world. Its relationship to the Mediterranean and Hawaiian monk seals, both living but endangered, has never been fully understood. Through DNA analysis and skull comparisons, however, Smithsonian scientists and colleagues have now clarified the Caribbean species' place on the seal family tree and created a completely new genus. The team's findings are published in the scientific journal ZooKeys.
First reported by Columbus in 1494, the Caribbean monk seal ranged throughout the Caribbean with an estimated population in the hundreds of thousands. Unrestricted hunting in the 19th century, however, caused a rapid decline in numbers. The last definite sighting of a Caribbean monk seal was in 1952, making it the most recent extinction of a marine mammal in the Western Hemisphere.
To find the answers about the classification of the Caribbean monk seal, the scientists turned to DNA extracted from century-old monk seal skins in the Smithsonian's collections. For the DNA comparisons, the Smithsonian team worked with scientists at the Leibniz Institute of Zoo and Wildlife Research in Germany and Fordham University in New York. Their analyses showed that the Caribbean species was more closely related to the Hawaiian rather than the Mediterranean monk seal. It also showed that Caribbean and Hawaiian monk seals split into distinct species around 3 to 4 million years ago―the same time the Panamanian Isthmus closed off the connection between the Atlantic and Pacific Oceans, which would have naturally separated the two.
"Scientists have long understood that monk seals are very special animals," said Kristofer Helgen, curator of mammals at Smithsonian's National Museum of Natural History. "This study is exciting because it gives us a clearer view of their evolution and provides us with new context that highlights the importance of conserving these remarkable and endangered seals."
The team's analysis determined that the molecular and morphological differences between the Mediterranean species and the two New World species (Caribbean and Hawaiian) were profound. This led them to classify the Caribbean and Hawaiian monk seals in a newly named genus, Neomonachus. This remarkable discovery is the first time in more than 140 years that a new genus has been recognized amongst modern pinnipeds (seals, sea lions, and walruses).
"We occasionally identify new species of larger mammals, like the olinguito we announced last year," said Graham Slater, co-author and Peter Buck Post Doctoral Fellow at the Smithsonian. "But to be able to name a new genus, and a seal genus at that, is incredibly rare and a great honor."
Monk seals, as a group, are unusual among seals in being adapted for life in warm water. With the Caribbean species now extinct, the Hawaiian monk seal is the last surviving species of the genus Neomonachus, as the Mediterranean species is in its genus, Monachus. Both species are listed as "critically endangered" by the International Union for Conservation of Nature. With about 1,200 Hawaiian but less than 600 Mediterranean monk seals left, they are some of the rarest mammals on Earth.

http://www.sciencedaily.com/releases/2014/05/140514100306.htm




Journal Reference:
Dirk-Martin Scheel, Graham Slater, Sergios-Orestis Kolokotronis, Charles Potter, David Rotstein, Kyriakos Tsangaras, Alex Greenwood, Kristofer M. Helgen. Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology. ZooKeys, 2014; 409: 1 DOI: 10.3897/zookeys.409.6244

Abstract
Extinctions and declines of large marine vertebrates have major ecological impacts and are of critical concern in marine environments. The Caribbean monk seal, Monachus tropicalis, last definitively reported in 1952, was one of the few marine mammal species to become extinct in historical times. Despite its importance for understanding the evolutionary biogeography of southern phocids, the relationships of M.tropicalis to the two living species of critically endangered monk seals have not been resolved. In this study we present the first molecular data for M. tropicalis, derived from museum skins. Phylogenetic analysis of cytochrome b sequences indicates that M. tropicalis was more closely related to the Hawaiian rather than the Mediterranean monk seal. Divergence time estimation implicates the formation of the Panamanian Isthmus in the speciation of Caribbean and Hawaiian monk seals. Molecular, morphological and temporal divergence between the Mediterranean and “New World monk seals” (Hawaiian and Caribbean) is profound, equivalent to or greater than between sister genera of phocids. As a result, we classify the Caribbean and Hawaiian monk seals together in a newly erected genus, Neomonachus. The two genera of extant monk seals (Monachus and Neomonachus) represent old evolutionary lineages each represented by a single critically endangered species, both warranting continuing and concerted conservation attention and investment if they are to avoid the fate of their Caribbean relative.

http://www.pensoft.net/journals/zookeys/article/6244/abstract/biogeography-and-taxonomy-of-extinct-and-endangered
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