The gray-bellied caenolestid (''Caenolestes caniventer''), or grey-bellied shrew opossum, is a

shrew opossum The family (biology), family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral mar ...

found in humid,

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

forests and moist grasslands of western

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

and northwestern

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

. It was first described by American zoologist

Harold Elmer Anthony Harold may refer to: People * Harold (given name), including a list of persons and fictional characters with the name * Harold (surname), surname in the English language * András Arató, known in meme culture as "Hide the Pain Harold" Arts a ...

in 1921. Little is known about the behavior of the gray-bellied caenolestid. It appears to be

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

(land-living) and

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...

(active around twilight) or

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

(active at night). Diet consists of

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

larvae, small

vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

s and plant material. The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

classifies the gray-bellied caenolestid as

near threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

Taxonomy and etymology

The gray-bellied caenolestid is one of the five members of ''

Caenolestes The common shrew opossums (genus ''Caenolestes'') are members of the family Caenolestidae. They are found in Colombia, Ecuador, Peru, and Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República ...

'', and is placed in the family

Caenolestidae The family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral marsupial line very e ...

(shrew opossums). It was first described by American zoologist

in 1921. In the latter part of 20th century, scientists believed that ''Caenolestes'' is closely related to ''Lestoros'' (the Incan caenolestid). Over the years, it became clear that ''Lestoros'' is morphologically different from ''Caenolestes''. A 2013 morphological and

mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

-based

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

study showed that the Incan caenolestid and the long-nosed caenolestid (''Rhyncholestes raphanurus'') form a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to ...

to ''Caenolestes''. The cladogram below is based on this study. Caenolestid fossils date to as early as the early

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

(nearly 55 mya). The generic name ''Caenolestes'' derives from the Greek words ''kainos'' ("new") and ''lestes'' ("robber", "pirate").

Ecology and behavior

Little is known about the behavior of the gray-bellied caenolestid. It appears to be

(land-living) and

(active around twilight) or

(active at night). It appears to be an "opportunistic feeder". Analysis of stomach contents of individuals from

suggested a diet comprised largely (up to 75%) by

larvae (such as

arachnid Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroon ...

s and

centipede Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, an ...

s); small

s and plant material are also consumed. A pregnant female captured in

was found to have two fetuses in its womb.

Distribution and status

The gray-bellied caenolestid inhabit cool, moist areas with good cover; it is known from humid,

temperate forest A temperate forest is a forest found between the tropical and boreal regions, located in the temperate zone. It is the second largest biome on our planet, covering 25% of the world's forest area, only behind the boreal forest, which covers abou ...

s at altitudes of up to , and moist grasslands in the

subtropics The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north and ...

. It occurs in small tunnels under tree roots by streams. The range covers western Ecuador and northwestern Peru. The

classifies the gray-bellied caenolestid as

. Its population has decreased by nearly 20% since the 1990s; numbers are feared to be declining due to deforestation and

agricultural expansion Agricultural expansion describes the growth of agricultural land (arable land, pastures, etc.) especially in the 20th and 21st centuries. The agricultural expansion is often explained as a direct consequence of the global increase in food and ene ...

. The gray-bellied caenolestid occurs in

Cajas National Park El Cajas National Park or Cajas National Park ( es, Parque Nacional El Cajas) is a national park in the highlands of Ecuador. It is located about 30 km west from Cuenca, the capital of the province of Azuay. The area of 285.44 km2 ...

and Mazán Ecological Reserve.

References

External links

* {{Taxonbar, from=Q194365 Shrew opossums Marsupials of South America Mammals of Ecuador Mammals of Peru Near threatened animals Near threatened biota of South America Mammals described in 1921 Taxonomy articles created by Polbot es:Caenolestes#Caenolestes caniventer