Maned rat

The maned rat or African crested rat (Lophiomys imhausi) is a large nocturnal, long-haired and bushy-tailed East Africanrodent that superficially resembles a porcupine. The world's only known poisonous rodent, the maned rat sequesters toxins from plants to fend off predators.^[2]

The head and body length ranges from 18–30.5 centimetres (7.1–12.0 in) long, with the tail 14.5–20.5 centimetres (5.7–8.1 in) long; the typical weight is 590–920 g (21–32 oz). The coat consists of long, silver and black-tipped guard hairs over a dense, woolly, grey and white undercoat, with the face and limbs having short, black fur. A mane of longer, coarser black-and-white banded hairs extends from the top of the animal's head to just beyond the base of the tail. This mane is bordered by a broad, white-bordered strip of hairs covering an area of glandular skin. The forelimbs and hind limbs have short black fur. The forefeet are large and digit 1 of the forefeet does not have a claw, while digits 2-5 have a well developed claw.^[3]

When the animal is threatened or excited, the mane erects and this strip parts, exposing the glandular area. The hairs in this area are, at the tips, like ordinary hair, but are otherwise spongy, fibrous, and absorbent with a honeycomb structure.^[4] The rat is known to deliberately smear these hairs with poison from the bark of the Acokanthera schimperi, the poison arrow tree, on which it chews, thus creating a defense mechanism that can sicken or even kill predators which attempt to bite it.^[5] It is the only rodent known to use and store toxins^[6] from a different species in nature to protect itself, with no known adverse effects to themselves.^[7]

L. imhausi differs from typical Muridae in having the temporal fossa roofed over a thin plate of bone, rudimentary clavicles, and an opposable hallux. The dorsal surface of the skull is covered with small bony projections which gives it a pebbled look. These projections are 0.3 mm across and are separated every 0.3 mm. On these grounds, it has been made the type of its own subfamily Lophiomyinae in the family Cricetidae;^[3] its dentition, is typical Cricetine.^[8] The dental formula is 1/1, 0/0, 0/0, 3/3, giving it a total of 16 teeth. The cusps of the molars are arranged biserially and connected medially by longitudinal enamel crests.^[3]

Its diet in the wild consists largely of leaves, fruit, and other plant material, but it has been known to eat meat, cereals, root vegetables, and insects in captivity. Food is eaten by sitting on its haunches and using its forepaws to bring food items to its mouth. It is the only species in the super family Muroidea whose stomach is highly compartmentalised. The stomach contains five anatomically discrete sections that superficially resemble the sacculated configuration characteristic of ruminantartiodactyls. Because of its large size and weight, L. imhausi may be one of the few muroid rodents that has symbiotic microflora in the foregut which can metabolise cellulose by gastric fermentation.^[3]

The habitat of the maned rat ranges from nearly sea level in Ethiopia and Somalia, to more typically the drier, highland forests and woodlands of Somalia, Ethiopia, Sudan, Tanzania, Uganda, and Kenya. Fossil remains have been found as far north as Palestine, however. They are often found in rocky areas or in hollow tree trunks and holes along the tops of ravines, and have also been found nesting among rocks on cliff-faces.

Se creía que la rata de crin era solitaria, pero ahora se sabe que es algo sociable, con varios animales atrapados en el mismo territorio; ronronean y se acicalan entre sí. Por lo tanto, es posible que formen grupos familiares de un macho, una hembra y crías. ^{[ 9 ]} El tamaño de la camada es de 1 a 3. Las crías nacen ligeramente peludas y las marcas blancas y las rayas negras en el cuerpo son visibles después de 9 días. Al día 13, abren los ojos. El pelo es lo suficientemente largo como para que la cresta pueda ser eréctil al día 20. Los recién nacidos comienzan a moverse al día 23 y son destetados al día 40. ^{[ 10 ]}

• Jansa, SA y M. Weksler. 2004. Filogenia de los roedores muroideos: relaciones dentro y entre los principales linajes determinadas por secuencias del gen IRBP. Molecular Phylogenetics and Evolution, 31:256-276.
• Kingdon, Jonathan. Mamíferos de África Oriental . Chicago: University of Chicago Press, 1974. 519–526.
• Jonathan Kingdon, Bernard Agwanda, Margaret Kinnaird, Timothy O'Brien, Christopher Holland, Tom Gheysens, Maxime Boulet-Audet y Fritz Vollrath 2011 Una sorpresa venenosa bajo el pelaje de la rata crestada africana Proc. R. Soc. Bdoi : 10.1098/rspb.2011.1169
• Jonathan Kingdon, David Happold , Thomas Butynski, Michael Hoffmann, Meredith Happold, Jan Kalina, Mamíferos de África , Vol. 1-6
• Jonathan Kingdon, La guía de campo Kingdon de los mamíferos africanos
• Schlitter, D. (2016). " Lophiomys imhausi " . Lista Roja de Especies Amenazadas de la UICN . 2016 e.T12308A22368581. doi : 10.2305/IUCN.UK.2016-2.RLTS.T12308A22368581.en . Consultado el 12 de noviembre de 2021 .La entrada en la base de datos incluye una breve justificación de por qué esta especie es de menor preocupación.

• " Lophiomys imhausi : rata crestada" . Animal Diversity Web . Consultado el 20 de noviembre de 2010 .
• Vídeo de un animal, un líquido absorbente de pelo e imagen SEM del pelo en YouTube: https://www.youtube.com/watch?v=pLheG3aSpVU