- Dwarf Manatee
-
Dwarf Manatee Conservation status Scientific classification (disputed) Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Sirenia Family: Trichechidae Genus: Trichechus Species: T. "pygmaeus" Binomial name Trichechus "pygmaeus" The Dwarf Manatee (Trichechus "pygmaeus", or mistakenly Trichechus "bernhardi")[2] is a possible species of manatee that lives in the freshwater habitats of the Amazon, though restricted to one tributary of the Aripuanã River.[3] According to Marc van Roosmalen, the scientist who proposes it as a new species, it lives in shallow, fast running water and feeds on different species of aquatic plants than the Amazonian Manatee, which prefers deeper slower moving waters and the plants found there. It is reported that the dwarf manatees migrate upriver during the rainy season when the river floods to the headwaters and shallow ponds. Based on its small range, it has been suggested that the Dwarf Manatee is critically endangered,[3] but at present it is not recognized by the IUCN.[1]
Dwarf Manatees are typically about 130 cm long, and weigh about 60 kg, making them the smallest extant sirenians.[3] It is overall very dark, almost black, with a white patch on the abdomen.[3] It has been suggested that it actually represents an immature Amazonian Manatee, but they are reported to differ in proportions and colour.[3] They are, however, at least very closely related, as mtDNA has failed to reveal any difference between the two. Based on mutation rates in manatees – if the Dwarf Manatee is distinct – this suggests a divergence time of less than 485,000 years.[3] Daryl Domning, a Smithsonian Institution research associate and the world's foremost experts on manatee evolution,[4] has stated that the DNA evidence actually proves that these merely are immature Amazonian Manatees.[5]
Disregarding its questionable validity as a species, the proposed name "Trichechus pygmaeus" is problematic. A formal description using that name was submitted to Nature, but it was rejected[2] and consequently the article has only been published online.[3] This has resulted in the invalidation of the name following chapter 3, article 8 of the ICZN code.[6]
References
- ^ a b International Union for Conservation of Nature (2008). IUCN Red List. Accessed November 09, 2009.
- ^ a b William. (2008). Interview with Marc van Roosmalen. aquaticcommunity.com. Accessed November 09, 2009.
- ^ a b c d e f g van Roosmalen, M. G. M. A new species of living manatee from the Amazon.. Accessed on March 15, 2008.
- ^ How Manatees Evolved. manateebrain.org. Accessed 2008-07-27
- ^ Trials of a Primatologist. smithsonianmag.com. Accessed 2008-07-27
- ^ International Commission on Zoological Nomenclature. (2000). International Code of Zoological Nomenclature. 4th edition. Accessed November 09, 2009.
External links
- Cryptomundo - (New Dwarf Manatee)
- Tetrapodzoology - (Multiple new species of large, living mammal (part II))
- Wildlife Extra
Categories:- Sirenians
Wikimedia Foundation. 2010.
