Rats, Mice, and Relatives: Muridae

They are most commonly some shade of brown in colour, although many have black, grey, or white markings. A broad range of feeding habits is found in murids, ranging from herbivorous and omnivorous species to specialists that consume strictly earthworms, certain species of fungi, or aquatic insects. Most genera consume plant matter and small invertebrates, often storing seeds and other plant matter for winter consumption. Murids have sciurognathous jaws (an ancestral character in rodents) and a diastema is present. Generally, three molars (though sometimes only one or two) are found, and the nature of the molars varies by genus and feeding habit. Murids have sciurognathous jaws (an ancestral character in rodents) and a diastema is present.[5] Murids lack canines and premolars.

Old World rats and mice have long tails (sometimes longer than the body) that are either furry or scaly; strong feet; long hind feet; and opposable digits on their front feet. Adults have a length of 1.9 to 14.7 inches (5 to 36 centimeters) and a weight of 0.2 to 52.9 ounces (5 grams to 1.5 kilograms). Persistently infected rodents shed the virus in urine, feces, and saliva. Inhalation of virus-contaminated aerosols is the major route of transmission to humans. However, the general view that rodents are the only infection source for humans has been disputed by Zeier et al. (2005). It has been suggested that the close proximity of domestic animals such as cats, dogs, pigs, and cattle with rodents may cause some transmission events of hantaviruses to these animals.

Some groups are known to be monophyletic (hamsters, voles, African pouched rats, gerbils, Old World rats and mice, African spiny mice, platacanthomyines, zokors, blind mole rats, and bamboo rats). Other groups, however, cannot be classified with certainty and may or may not be a hodgepodge of unrelated genera and species (New World rats and mice, dendromurines, and Malagasy rats and mice). Also unresolved are the affinities of subfamilies containing only one genus (mouselike hamsters, the maned rat). The Muridae is the largest family of mammals (numbering over 1300 species), with a great variety of adaptations to life in and around water. Oddly, however, there are no water rats in the Asian tropics.

The Murids are classified in four subfamilies, and about 140 genera. The family name Muridae is sometimes used in a broader sense to include all members of the superfamily Muroidea. The rat is commonly transmitted poison from the bark of the poison arrow tree, Acokanthera schimperi, on which it eats, on these hairs, forming a defensive mechanism that can sicken or even kill predators that try to bite it. The forefeet are big, and digit 1 does not have a claw, but digits 2–5 have a well-developed claw. The maned rat, also known as the (African) crested rat (Lophiomys imhausi), is a nocturnal, long-haired, bushy-tailed East African rodent with a porcupine-like appearance. Rats, mice, and relatives are found throughout the world except for the extreme polar regions of Earth.

Gerbils, jirds, and sand rats are all members of the Gerbillinae subfamily of the Muridae rodent family. Almost 450 species of murids are listed on the World Conservation Union’s (IUCN) Red List. Animals that use metabolically generated heat to regulate body temperature independently of ambient temperature.

The rare Ethiopian water mouse (Nilopegamys plumbeus) is known only from a mountain tributary of the Blue Nile, and is critically endangered (IUCN, 2006); it may even be extinct. It is the only African rodent to show the degree of adaptation to aquatic life and swimming ability evident in the Neotropical Ichthyomyinae and in the Australian Hydromyinae (Peterhans and Patterson, 1995). Goslingi or Malacomys spp., which belong to the ‘wading murid’ niche and have feet that are elongated and thin. They serve the purpose of raising the body so that these animals can hunt by wading in shallow water (Kingdon, 1974). The Muridae, or murids, are the biggest rodent and mammal family in the world, with over 700 species including many mice, rats, and gerbils found in Eurasia, Africa, and Australia.

Deomyinae is the older term, hence it takes priority over Acomyinae. Although modest elements of the third upper molar have been postulated, deomyines share no morphological traits that may be utilised to distinguish them from other muroids. The only thing that binds this subfamily together is a set of genetic mutations. They are found from dry temperate (mild) climates to wet tropical environments. It has also been touted as a model of autoimmune thyroiditis (Solleveld et al., 1985) and as a potentially useful model for reproductive biology with the successful development of an in vitro fertilization procedure (Nohara et al., 1998). Mastomys has been used most extensively as a model of gastric neoplasia (Nilsson et al., 1992; Gilligan et al., 1995).

Among Aesop’s Fables are The Cat and the Mice and The Frog and the Mouse. In James Herbert’s first novel, The Rats, (1974), a vagrant is attacked and eaten alive by a pack of giant rats; further attacks follow. The name Muridae comes from the Latin mus (genitive muris), meaning “mouse”, since all true mice belong to the family, with What do elephants eat the more typical mice belonging to the genus Mus. Four clawed digits are found on each forefoot (the pollex or “thumb” is small and bears a nail); the hind foot in most has five clawed digits (but sometimes the hallux or first toe has a nail). Other external features (ears, eyes, tail, pelage, etc.) are extremely variable.

They are thought to have developed from hamster-like creatures in tropical Asia during the early Miocene and have only generated species that can survive in colder regions since then. As a result of hitching a ride alongside human migrations throughout the current geological age, they have grown notably abundant globally. Another large group, restricted to Africa and the Middle East to Central Asia. Most species inhabit dry areas with sparse vegetation, including deserts. Granivorous and herbivorous, but some also consume large numbers of insects.

Above, the animal is dark to grey-brown, and below, it is pale grey-brown. The zygomatic plate is massive, the snout is long and wide, and the interorbital breadth is broad). The Togo mouse is thought to be insectivorous based on its skull anatomy. Mice are members of the Rodentia order’s Muridae rat family.

Murids are found nearly everywhere in the world, though many subfamilies have narrower ranges. Although none of them are native to the Americas, a few species, notably the house mouse and black rat, have been introduced worldwide. Murids occupy a broad range of ecosystems from tropical forests to tundras. Fossorial, arboreal, and semiaquatic murid species occur, though most are terrestrial animals.[4] The extensive list of niches filled by murids helps to explain their relative abundance.

Although none of them is native to the Americas, a few species, notably the house mouse and black rat, have been introduced worldwide. Fossorial, arboreal, and semiaquatic murid species occur, though most are terrestrial. The extensive list of niches filled by murids helps to explain their relative abundance.

Having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. The mane erects when the animal is scared or agitated, stripping portions and exposing the glandular region.