External skin gland on the back, neck, and shoulder of toads, some frogs, and salamanders
For one of the human salivary glands, see parotid gland.
The parotoid gland can be seen just behind the tympanum (ear) of this cane toad.
The parotoid gland (alternatively, paratoid gland) is an external skin gland on the back, neck, and shoulder of some frogs (especially toads), and salamanders. It can secrete a number of milky alkaloid substances (depending on the species) known collectively as bufotoxins, which act as neurotoxins to deter predation. These cutaneous glands are called parotoid as they are somewhat similarly positioned to mammalian parotid gland, although the latter have a different function, excreting saliva within the mouth rather than externally excreted defensive chemicals.
A study of the parotoid glands of the Colorado River toad in 1976 found that the parotoid glands were "composed of numerous lobules", each of which is a separate unit with a lumen surrounded by a double cell layer. The cell layers have interlocking microvilli. The study found that the outer cell layer resembled smooth muscle cells, with some organelles hypothesised to "function in some aspects of venom synthesis, active cellular transport and contraction in the discharge of the secretory product". The inner layer was hypothesised to be "involved in venom formation and release". The study noted that the structure of the parotoid glands of the Colorado River toad is very different from the structure of the same glands in the cane toad.[1] There is extensive blood supply to the parotoid glands to deliver cholesterol and other toxin precursor chemicals to the gland.[2]
Parotoid glands are sometimes said to be wart-like in appearance, though warts are abnormal growths caused by viral infections while parotoid glands are normal, healthy parts of the animals that bear them. The vague similarity in appearance, however, is the reason behind the mistaken belief that touching a toad causes warts.[3]
↑ Cannon MS, Hostetler JR (February 1976). "The anatomy of the parotoid gland in Bufonidae with some histochemical findings. II. Bufo alvarius". Journal of Morphology. 148 (2): 137–60. doi:10.1002/jmor.1051480202. PMID1254079. S2CID22652419.
↑ Hutchinson DA, Savitzky AH (May 2004). "Vasculature of the parotoid glands of four species of toads (Bufonidae: Bufo)". Journal of Morphology. 260 (2): 247–54. doi:10.1002/jmor.10219. PMID15108163. S2CID41677294.
The cane toad, also known as the giant neotropical toad or marine toad, is a large, terrestrial true toad native to South and mainland Central America, but which has been introduced to various islands throughout Oceania and the Caribbean, as well as Northern Australia. It is a member of the genus Rhinella, which includes many true toad species found throughout Central and South America, but it was formerly assigned to the genus Bufo.
Bufo is a genus of true toads in the amphibian family Bufonidae. As traditionally defined, it was a wastebasket genus containing a large number of toads from much of the world, but following taxonomic reviews most of these have been moved to other genera, leaving only seventeen extant (living) species from Europe, northern Africa and Asia in this genus, including the well-known common toad. Some of the genera that contain species formerly placed in Bufo are Anaxyrus, Bufotes, Duttaphrynus, Epidalea and Rhinella.
The common toad, European toad, or in Anglophone parts of Europe, simply the toad, is a frog found throughout most of Europe, in the western part of North Asia, and in a small portion of Northwest Africa. It is one of a group of closely related animals that are descended from a common ancestral line of toads and which form a species complex. The toad is an inconspicuous animal as it usually lies hidden during the day. It becomes active at dusk and spends the night hunting for the invertebrates on which it feeds. It moves with a slow, ungainly walk or short jumps, and has greyish-brown skin covered with wart-like lumps.
Bufotenin is a tryptamine derivative, more specifically, a DMT analog, related to the neurotransmitter serotonin. It is an alkaloid found in some species of mushrooms, plants and toads, especially the skin.
Bufotoxins are a family of toxic steroid lactones or substituted tryptamines of which some are toxic. They occur in the parotoid glands, skin, and poison of many toads and other amphibians, and in some plants and mushrooms. The exact composition varies greatly with the specific source of the toxin. It can contain 5-MeO-DMT, bufagins, bufalin, bufotalin, bufotenin, bufothionine, dehydrobufotenine, epinephrine, norepinephrine, and serotonin. Some authors have also used the term bufotoxin to describe the conjugate of a bufagin with suberylarginine.
Bufagin is a toxic steroid C24H34O5 obtained from toad's milk, the poisonous secretion of a skin gland on the back of the neck of a large toad (Rhinella marina, synonym Bufo marinus, the cane toad). The toad produces this secretion when it is injured, scared or provoked. Bufagin resembles chemical substances from digitalis in physiological activity and chemical structure.
Bufotalin is a cardiotoxic bufanolide steroid, cardiac glycoside analogue, secreted by a number of toad species. Bufotalin can be extracted from the skin parotoid glands of several types of toad.
The Colorado River toad, also known as the Sonoran Desert toad, is a toad species found in northwestern Mexico and the southwestern United States. It is well known for its ability to exude toxins from glands within its skin that have psychoactive properties.
The American toad is a common species of toad found throughout Canada and the eastern United States. It is divided into three subspecies: the eastern American toad, the dwarf American toad and the rare Hudson Bay toad. Recent taxonomic treatments place this species in the genus Anaxyrus instead of Bufo.
A true toad is any member of the family Bufonidae, in the order Anura. This is the only family of anurans in which all members are known as toads, although some may be called frogs. The bufonids now comprise more than 35 genera, Bufo being the best known.
Bufo bankorensis is a species of toad in the family Bufonidae. It is endemic to Taiwan and widely distributed at elevations up to 3,000 m (9,800 ft) above sea level. There has been doubts about its separatedness from Bufo gargarizans from China and even other species, but it is currently considered a valid species.
Rhinella icterica is a species of toad in the family Bufonidae that is found in northeastern Argentina, southern Brazil, and eastern Paraguay. "Cururu" is its indigenous name and refers to the male advertisement call that is a melodious tremolo. "Cururu toad", without the specifier "yellow", is a common name used for a few other closely related species.
Sclerophrys kerinyagae is a species of toad in the family Bufonidae. It is found in central Ethiopia, Kenya, northern Tanzania, and eastern Uganda. Common names Keith's toad and Kerinyaga toad have been coined for it.
The Arizona toad is a species of toad in the family Bufonidae. It is endemic to the south-western United States, where its natural habitats are temperate lowland forests, rivers and streams, swamps, freshwater marshes, freshwater springs, ponds, open excavations, irrigated land, and seasonally flooded agricultural land.
The raucous toad, also known as Ranger's toad, is a species of toad from Southern Africa.
Rentapia everetti, also known as Everett's Asian tree toad or marbled tree toad, is a species of toad in the family Bufonidae. It is endemic to Borneo and occurs in both Malaysia, Brunei, and Indonesia.
Bufothionine is a sulfur-containing compound which is present in the bufotoxins secreted by the parotoid gland of certain toads of the genera Bufo and Chaunus. This specific compound can be found in the skin of certain species of toad such as the Asiatic Toad, Chaunus arunco, Chaunus crucifer, Chaunus spinulosus, and Chaunus arenarum.
HuaChanSu is a traditional Chinese medicine extracted from the skin of toads from the genus Bufo that is believed by some to slow the spread of cancerous cells. The parotoid gland of toads of the Bufo genus secrete a venom, which is dried and dissolved in water. This solution, HuaChanSu, is injected into a cancerous area and targets specific cancer cells. HuaChanSu is undergoing further trials, and its effect is not completely understood.
The Hot Creek toad is a species of toad in the family Bufonidae. It is endemic to Nye County in the state of Nevada in the United States.
The Railroad Valley toad is a species of toad in the family Bufonidae. It is endemic to Nye County in the state of Nevada in the United States.
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