Nimba otter shrew | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Afrosoricida |
Suborder: | Tenrecomorpha |
Family: | Potamogalidae |
Genus: | Micropotamogale |
Species: | M. lamottei |
Binomial name | |
Micropotamogale lamottei Heim de Balsac, 1954 | |
Nimba otter shrew range |
The Nimba otter shrew (Micropotamogale lamottei) is a dwarf otter shrew and belongs to the mammal family Potamogalidae. Otter shrews are shrew-like afrotherian mammals found in sub-Saharan Africa. They are most closely related to the tenrecs of Madagascar. [2] This species belongs to the genus Micropotamogale , literally meaning "tiny river weasel". It is native to the Mount Nimba area which rests along the border of Liberia, Guinea, and Côte d’Ivoire (Ivory Coast) in West Africa.
The Nimba otter shrew is a small-bodied mammal. Weighing only about 125 g (4.4 oz) it has a body length of 15–22 cm (5.9–8.7 in) with a quarter to a third of its body size being its tail. It has been described as a "miniature sea otter with a rat tail". [3] Its pelage is long, hiding its ears and eyes, and almost always universally colored (usually brown, but black and gray otter shrews have been spotted). [4]
The Nimba otter shrew is classified as a member of Potamogalidae, which is related to afrotherian tenrecs, based on morphological structures. Molecular data also support the relationship. [5] Unfortunately, due to heavy mining operations for iron ore in the Mount Nimba area, the fossil record is all but destroyed. It is also difficult for scientists to gain access because the mountain crosses the borders of three different countries. [6]
The Nimba otter shrew is nocturnal and semiaquatic. [4] It resides in soft soils around creek beds and streams. It is a solitary creature and has only been seen with other shrews during mating seasons and when a mother is nursing newly born young. [7] The breeding pattern of the Nimba otter shrew is also unknown, but believed to be polygamous; as there have been no witnessed accounts of breeding in the wild and the Nimba otter shrew has not mated in captivity. [8]
The IUCN had listed the Nimba otter shrew as endangered in 1990, but in 2018 the status was changed to vulnerable. [1] The species is confined to an area of less than 5,000 km² on Mount Nimba, which is currently fragmented due to mining and wetland rice agriculture. The mining operations also produce runoff into the creeks and streambeds that is highly toxic. [8] The current population is decreasing at a rate of 1 per 10 km² (almost 500 otter shrews per year). [1] Although an exact number is unknown at this time, there is believed to be less than 2500–3500 individuals in the wild; there are none in captivity. [9] At this rate the Nimba otter shrew was predicted to be extinct between 2017 and 2020. [10] The population within Liberia's East Nimba Nature Reserve was reported healthy in 2013. [1] The species is also present in the Mount Nimba Strict Nature Reserve of Guinea and Côte d’Ivoire, but this reserve is adjacent to a mining operation and is not fully protected from poaching. [1]
The clade Tenrecoidea or Afrosoricida contains the golden moles of Southern Africa, the otter shrews of equatorial Africa and the tenrecs of Madagascar. These three groups of small mammals were for most of the 19th and 20th centuries regarded as a part of the Insectivora or Lipotyphla. Both groups, as traditionally used, are polyphyletic.
Tenrecomorpha is the suborder of otter shrews and tenrecs, a group of afrotherian mammals indigenous to equatorial Africa and Madagascar, respectively. The two families are thought to have split about 47–53 million years ago. Potamogalid otter shrews were formerly considered a subfamily of Tenrecidae. The suborder is also presumed to contain the extinct genus Plesiorycteropus, a group of possibly fossorial insectivores similar to aardvarks, which is known to be more closely related to tenrecs of subfamily Tenrecinae than to golden moles of suborder Chrysochloridea.
A tenrec is any species of mammal within the afrotherian family Tenrecidae, which is endemic to Madagascar. Tenrecs are a very diverse group; as a result of convergent evolution some resemble hedgehogs, shrews, opossums, rats, and mice. They occupy aquatic, arboreal, terrestrial, and fossorial environments. Some of these species including the greater hedgehog tenrec, can be found in the Madagascar dry deciduous forests. However, the speciation rate in this group has been higher in humid forests.
Afrotheria is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews, tenrecs, aardvarks, hyraxes, elephants, sea cows, and several extinct clades. Most groups of afrotheres share little or no superficial resemblance, and their similarities have only become known in recent times because of genetics and molecular studies. Many afrothere groups are found mostly or exclusively in Africa, reflecting the fact that Africa was an island continent from the Cretaceous until the early Miocene around 20 million years ago, when Afro-Arabia collided with Eurasia.
Lipotyphla is a formerly used order of mammals, including the members of the order Eulipotyphla as well as three other families of the former order Insectivora, Chrysochloridae, Tenrecidae (tenrecs), and Potamogalidae. However, molecular studies found the golden moles, tenrecs, and otter shrews to be unrelated to the others. This made Lipotyphla an invalid polyphyletic order and gave rise to the notion of Eulipotyphla instead, an exclusively laurasiathere grouping.
The giant otter shrew is a semiaquatic, carnivorous afrotherian mammal. It is found in the main rainforest block of central Africa from Nigeria to Zambia, with a few isolated populations in Kenya and Uganda. It lives in streams, wetlands and slow flowing larger rivers. It is the only species in the genus Potamogale. Otter shrews are most closely related to the tenrecs of Madagascar.
The web-footed tenrec, Malagasy otter shrew, or aquatic tenrec is the only known semiaquatic tenrec, and is found in eastern Madagascar, especially in and around Ranomafana National Park. It grows to between 25 and 39 cm, and was once thought to be extinct. It feeds on crabs, aquatic insects, and crayfish. The population is considered vulnerable. It was formerly placed in the monotypic genus Limnogale, but has been moved to Microgale based on molecular data showing it to be deeply nested within the latter.
Mount Nimba Strict Nature Reserve is a protected area and UNESCO World Heritage Site located in both Guinea and Côte d'Ivoire, extending over a total of area of 175.4 km2, with 125.4 km2 in Guinea, and 50 km2 in Côte d'Ivoire. The reserve covers significant portions of the Nimba Range, a geographically unique area with unusually rich flora and fauna, including exceptional numbers of single-site endemic species, such as Nimbaphrynoides, the Nimba otter shrew, and multiple species of horseshoe bats. Its highest peak is Mount Richard-Molard at 1,752 m (5,750 ft), which is the highest peak of both countries.
The Upper Guinean forests is a tropical seasonal forest region of West Africa. The Upper Guinean forests extend from Guinea and Sierra Leone in the west through Liberia, Côte d'Ivoire and Ghana to Togo in the east, and a few hundred kilometers inland from the Atlantic coast. A few enclaves of montane forest lie further inland in the mountains of central Guinea and central Togo and Benin.
The Afroinsectiphilia is a clade that has been proposed based on the results of recent molecular phylogenetic studies. Many of the taxa within it were once regarded as part of the order Insectivora, but Insectivora is now considered to be polyphyletic and obsolete. This proposed classification is based on molecular studies only, and there is no morphological evidence for it.
The Ruwenzori otter shrew is a species of semiaquatic dwarf otter shrew of the family Potamogalidae. It is found in the Democratic Republic of the Congo, Rwanda, and Uganda. Otter shrews are shrew-like afrotherian mammals found in sub-Saharan Africa. They are most closely related to the tenrecs of Madagascar.
Micropotamogale is a genus of small, otter-like dwarf otter shrews native to riverine habitats of West African rainforests. They feed on aquatic animals and insects they can find and capture. They are afrotherian mammals most closely related to the tenrecs of Madagascar, but are not closely related to shrews or otters.
The large-toothed shrew or Mexican large-toothed shrew is one of 77 species within the genus Sorex. Registered on the IUCN Red List as vulnerable with a decreasing population, the Mexican large-toothed shrew has been recorded only 14 times in seven locations. The shrew is a member of the red-toothed shrew subfamily Soricinae, and the more taxonomically defined tribe Soricini. Members of the latter category exhibit long tails relative to body size.
Lamotte's roundleaf bat is a species of bat found only at Mount Nimba on the border of Côte d'Ivoire, Guinea and Liberia. It is critically endangered.
Potamogalidae is the family of "otter shrews", a group of semiaquatic riverine afrotherian mammals indigenous to sub-Saharan Africa. They are most closely related to the tenrecs of Madagascar, from which they are thought to have split about 47–53 million years ago. They were formerly considered a subfamily of Tenrecidae.
The Nimba Range forms part of the southern extent of the Guinea Highlands. The highest peak is Mount Richard-Molard on the border of Côte d'Ivoire and Guinea, at 1,752 m (5,748 ft). "Mount Nimba" may refer either to Mount Richard-Molard or to the entire range. Other peaks include Grand Rochers at 1,694 m (5,558 ft), Mont Sempéré at 1,682 m (5,518 ft), Mont Piérré Richaud at 1,670 m (5,480 ft), Mont Tô at 1,675 m (5,495 ft), and Mont LeClerc 1,577 m (5,174 ft), all of them are located in Guinea. Mount Nimba Strict Nature Reserve of Guinea and Côte d'Ivoire covers significant portions of the Nimba Range.