The Nimba otter shrew (''Micropotamogale lamottei'') is a dwarf otter shrew and belongs to the mammal family
Potamogalidae. Otter shrews are shrew-like
afrotheria
Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a superorder of placental mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephan ...
n mammals found in sub-Saharan Africa. They are most closely related to the
tenrec
A tenrec () is a mammal belonging to any species within the afrotherian family Tenrecidae, which is endemic to Madagascar. Tenrecs are a very diverse group, as a result of adaptive radiation, and exhibit convergent evolution, some resemble hed ...
s of Madagascar.
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
Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Lib ...
,
Guinea
Guinea, officially the Republic of Guinea, is a coastal country in West Africa. It borders the Atlantic Ocean to the west, Guinea-Bissau to the northwest, Senegal to the north, Mali to the northeast, Côte d'Ivoire to the southeast, and Sier ...
, and
Côte d’Ivoire (Ivory Coast) in
West Africa
West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...
.
Description
The Nimba otter shrew is a small-bodied mammal. Weighing only about it has a body length of 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".
Its
pelage
A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...
is long, hiding its ears and eyes, and almost always universally colored (usually brown, but black and gray otter shrews have been spotted).
Evolution and life history
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.
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.
Ecology and behavior
The Nimba otter shrew is
nocturnal
Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite.
Nocturnal creatur ...
and
semiaquatic
In biology, being semi-aquatic refers to various macroorganisms that live regularly in both aquatic and terrestrial environments. When referring to animals, the term describes those that actively spend part of their daily time in water (in ...
.
It resides in soft soils around creek beds and
stream
A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...
s.
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.
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.
Conservation status
The IUCN had listed the Nimba otter shrew as ''endangered'' in 1990, but in 2018 the status was changed to ''vulnerable''.
The
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
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.
The current population is decreasing at a rate of 1 per 10 km² (almost 500 otter shrews per year).
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.
At this rate the Nimba otter shrew was predicted to be extinct between 2017 and 2020.
The population within Liberia's
East Nimba Nature Reserve was reported healthy in 2013.
The species is also present in the
Mount Nimba Strict Nature Reserve
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 , with in Guinea, and in Côte d'Ivoire. The reserve covers significant portion ...
of Guinea and Côte d’Ivoire, but this reserve is adjacent to a mining operation and is not fully protected from poaching.
References
{{Taxonbar, from=Q243994
Afrosoricida
EDGE species
Mammals described in 1954
Aquatic mammals
Taxa named by Henri Heim de Balsac