| Grasshopper mice Temporal range: Early Pliocene – Present | |
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| A grasshopper mouse eating a beetle | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Cricetidae |
| Subfamily: | Neotominae |
| Tribe: | Reithrodontomyini |
| Genus: | Onychomys Baird, 1857 |
| Type species | |
| Hypudaeus leucogaster [1] | |
| Species | |
Grasshopper mice are rodents of the genus Onychomys, occurring in North America. They feed on insects and other arthropods.
The three species in this genus of New World mice are only distantly related to the common house mouse, Mus musculus . They are endemic to the United States and Mexico. The southern grasshopper mouse has around a 3.5 to 5.0 inches (8.9–12.7 cm) long body and a tail that is generally 1.0 to 2.5 inches (2.5–6.4 cm) long. [2] Its behavior is distinct from other mice.
It is a carnivorous rodent, dining on insects (such as grasshoppers), worms, spiders, centipedes, mantis, scorpions, snakes, and even other mice. It also stalks its prey in the manner of a cat, sneaking up quietly, and defends its territory by "howling" like a small wolf. The grasshopper mouse is known to be immune to various venoms released by its prey (scorpions, snakes, etc.). [3] Grasshopper mice are nocturnal and avoid exposure to bright light. [4]
Grasshopper mice prey on highly venomous arthropods. One example is centipedes that normally kill less resistant mice by injecting deadly toxins through their venomous forcipules. Grasshopper mice move swiftly, while centipedes can only inject their toxin if their prey is held by the centipede's needle-sharp claws. The mouse is agile enough to stay out of the reach of the centipede's claws. The mouse attacks by repeatedly biting through the centipede's hard exoskeleton. Each attack on the centipede damages its central nervous system, until the centipede is paralyzed and the grasshopper mouse can eat it safely.
Another example of a venomous arthropod is the bark scorpion (Centruroides sculpturatus). The grasshopper mouse survives in the deserts of southwest United States by feeding on the bark scorpion, which are plentiful, due to other resources being less common. [5]
Their aggressive nature extends beyond their hunting habits: when held in captivity with other mice, they will often kill and eat those other mice. However, they have a disadvantage when it involves capturing in open areas because of their short legs and wide bodies (which reduces their speed). Due to their ability to maneuver well, they are able to move quickly in narrow areas allowing them to capture their prey more efficiently. [4]
The bark scorpion and the grasshopper mouse have been coevolving with each other so closely that it has affected their physiology. The scorpion uses its stinger to inject toxins into the nervous and muscle tissues which causes disruption in the animal's sensory system. However, as the scorpion's stinger evolves to become more toxic, the mice evolve in order to cope with the toxins. Grasshopper mice have evolved sensory neurons which reject the toxins and prevent pain signals. [6] Researchers now know that the grasshopper mouse barely notices the intensifying sting due to a mutation in the cellular pathway that controls their pain response. Compared to the normal house mouse, the grasshopper mouse has one more amino acid in the protein making up the sodium channel Na+ nav1.8. This change prevents the mouse from processing Na+ currents when injected with the scorpion's venom, which blocks action potential propagation and induces analgesia. [7] The Grasshopper Mouse's mutation may potentially yield better analgesics for humans as well, through further research. [5]
Onychomys have six different vocalization types (two neonatal and four adult). They have a wide range of calls that can distinguish them between species, sex, and individuals. For example, the larger mice tend to have deeper voices. [8] When they feel attacked, they will let out a rapid screech/bark. [4]
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism.
A stinger is a sharp organ found in various animals capable of injecting venom, usually by piercing the epidermis of another animal.
The Arizona bark scorpion is a small light brown scorpion common to the Sonoran Desert in the southwestern United States and northwestern Mexico. An adult male can reach 8 cm in length (3.14 inches), while a female is slightly smaller, with a maximum length of 7 cm (2.75 inches).
The Chinese red-headed centipede, also known as the Chinese red head, is a centipede from East Asia. It averages 20 cm (8 in) in length and lives in damp environments.
Mearns's grasshopper mouse or the Chihuahuan grasshopper mouse is a grasshopper mouse found in southwestern New Mexico, West Texas, and north-central Mexico. They are similar to Onychomys torridus, but differ in karyotype and size. This mouse is smaller in every regard except for the nasal length of the skull.
Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow or grooved fangs, although some venomous snakes lack well-developed fangs. Common venomous snakes include the families Elapidae, Viperidae, Atractaspididae, and some of the Colubridae. The toxicity of venom is mainly indicated by murine LD50, while multiple factors are considered to judge the potential danger to humans. Other important factors for risk assessment include the likelihood that a snake will bite, the quantity of venom delivered with the bite, the efficiency of the delivery mechanism, and the location of a bite on the body of the victim. Snake venom may have both neurotoxic and hemotoxic properties. There are about 600 venomous snake species in the world.
The striped bark scorpion is an extremely common scorpion found throughout the midsection of the United States and northern Mexico. It is perhaps the most frequently encountered scorpion in the U.S.
Scolopendra subspinipes is a species of very large centipede found throughout southeastern Asia. One of the most widespread and common species in the genus Scolopendra, it is also found on virtually all land areas around and within the Indian Ocean, all of tropical and subtropical Asia from Russia to the islands of Malaysia and Indonesia, Australia, South and Central America, the Caribbean islands, and possibly parts of the southern United States, but how much of this range is natural and how much due to human introduction is unclear. With a wide geographic range and numerous color variations, the species is known by many common names, including jungle centipede, orange-legged centipede, Hawaiian centipede, and Vietnamese centipede.
The southern grasshopper mouse or scorpion mouse is a species of predatory rodent in the family Cricetidae, native to Mexico and the states of Arizona, California, Nevada, New Mexico, and Utah in the United States. Notable for its resistance to venom, it routinely preys on the highly venomous Arizona bark scorpion.
Forcipules are the modified, pincer-like, front legs of centipedes that are used to inject venom into prey. They are the only known examples of front legs acting as venom injectors.
A scorpion sting is an injury caused by the stinger of a scorpion resulting in the medical condition known as scorpionism, which may vary in severity. The anatomical part of the scorpion that delivers the sting is called a "telson". In typical cases, scorpion stings usually result in pain, paresthesia, and variable swelling. In serious cases, scorpion stings may involve the envenomation of humans by toxic scorpions, which may result in extreme pain, serious illness, or even death depending on the toxicity of the venom.
Many species of arthropods can bite or sting human beings. These bites and stings generally occur as a defense mechanism or during normal arthropod feeding. While most cases cause self-limited irritation, medically relevant complications include envenomation, allergic reactions, and transmission of vector-borne diseases.
Tityus serrulatus, the Brazilian yellow scorpion, is a species of scorpion of the family Buthidae. It is native to Brazil, and its venom is extremely toxic. It is the most dangerous scorpion in South America and is responsible for the most fatal cases.
Androctonus bicolor, the black fat-tailed scorpion, is a scorpion species of the family Buthidae. It is black in color and can grow up to 8 cm. Black fat-tailed scorpions come from the family Buthidae, which is the largest of the scorpion family. They can be identified by their hefty physique. They tend to move very fast, and are of an aggressive nature. Black fat–tailed scorpions can live for up to 5 years. Adults can reach up to 40-60 millimeters, 80 millimeters being the maximum. These scorpions typically possess black and brown coloration. These scorpions enjoy making scrapes with wood and rocks, and are nocturnal, thus they hide in crevices or certain objects during the day. They stay in shade to retain moisture in their bodies, as they are susceptible to losing moisture due to their environmental preference.
Scolopendra morsitans, also known as the Tanzanian blue ringleg or red-headed centipede, is a species of centipede in the family Scolopendridae. S. morsitans is the type species for the genus Scolopendra.
Onychocerus albitarsis is a relatively rare species of beetle in the family Cerambycidae from the Amazon and Atlantic forest regions in Brazil, Bolivia, Paraguay and southern Peru. It is remarkable for being the only known beetle that has a venomous sting and the only known arthropod that stings with its antennae. Each antenna ends in a stinger that has evolved to resemble a scorpion's tail and it is connected to a venom gland. The sting was already reported in 1884 but researchers thought the pain only was caused by the sharpness of the antennae, as also known from some other beetles. It was only confirmed in 2005 that it is venomous when a biologist was stung, comparing it to a bee sting, and subsequently studied it in detail. In the first of two other cases where the identity of the stinging insect was confirmed to be this beetle, a woman experienced significant pain directly after the incident, and redness and itching at the sting site that lasted for a week. In the other case a man experienced moderate pain directly after being stung and redness that only lasted for an hour. The other species in the genus Onychocerus appear to not be venomous since they lack the structures inside the antennae that are associated with the venom apparatus of Onychocerus albitarsis.
Venom in snakes and some lizards is a form of saliva that has been modified into venom over its evolutionary history. In snakes, venom has evolved to kill or subdue prey, as well as to perform other diet-related functions. While snakes occasionally use their venom in self defense, this is not believed to have had a strong effect on venom evolution. The evolution of venom is thought to be responsible for the enormous expansion of snakes across the globe.
Leiurus abdullahbayrami is a species of scorpion in the family Buthidae. Its venom is highly toxic to humans, but can be used in medical development.
Scorpionism is defined as the accidental envenomation of humans by toxic scorpions. If the injection of venom in a human results in death, this is defined as scorpionism. This is seen all over the world but is predominantly seen in the tropical and subtropical areas. These areas include Mexico, northern South America and southeast Brazil in the Western hemisphere. In the Eastern hemisphere, scorpionism possess a public health threat in the regions of South Africa, the Middle East, and the Indian subcontinent.
| Authority control databases: National |
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