True toad

A true toad is any member of the family Bufonidae, in the order Anura (frogs and toads). This is the only family of anurans in which all members are known as toads, although some may be called frogs (such as harlequin frogs). The bufonids now comprise more than 35 genera, Bufo being the best known.

True toads Temporal range: 57–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N Late Paleocene – Recent[1]
Common toad or European toad, Bufo bufo
Territorial call of an Atelopus franciscus male
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Clade:	Hyloidea
Family:	Bufonidae Gray, 1825
Genera
Over 35 see text
Native distribution of Bufonidae (in black)

Characteristics

True toads are widespread and are native to every continent except Australia and Antarctica, inhabiting a variety of environments, from arid areas to rainforest. Most lay eggs in paired strings that hatch into tadpoles, although, in the genus Nectophrynoides, the eggs hatch directly into miniature toads.[1]

True toads are toothless and generally warty in appearance. They have a pair of parotoid glands on the back of their heads. These glands contain an alkaloid poison which the toads excrete when stressed. The poison in the glands contains a number of toxins causing different effects. Bufotoxin is a general term. Different animals contain significantly different substances and proportions of substances. Some, like the cane toad Rhinella marina, are more toxic than others. Some "psychoactive toads", such as the Colorado River toad Incilius alvarius,[2] have been used recreationally for the effects of their bufotoxin.

Male toads possess a Bidder's organ. Under the right conditions, the organ becomes an active ovary and the toad, in effect, becomes female.[3]

Reproduction

Internal fertilization occurs in four bufonid genera.[4]

• Mertensophryne (some species)
• Nectophrynoides (presumably all species)
• Altiphrynoides malcolmi (one out of two species in the genus Altiphrynoides)
• Nimbaphrynoides occidentalis (the sole species in the monotypic genus Nimbaphrynoides)

Ascaphus (all species) and Eleutherodactylus (two species, E. coqui and E. jasperi) are the only other frog genera that have internal fertilization.[4] Limnonectes larvaepartus also has internal fertilization.[5]

Taxonomy

The family Bufonidae contains over 570 species among 52 genera.

Genus Latin name and author	Common name	Species
Adenomus Cope, 1861	Dwarf toads	2
Altiphrynoides Dubois, 1987	Ethiopian toads	2
Amazophrynella Fouquet et al., 2012		12
Anaxyrus Tschudi, 1845		23
Ansonia Stoliczka, 1870	Stream toads	34
Atelopus Duméril & Bibron, 1841	Stubfoot toads	96
Barbarophryne Beukema, de Pous, Donaire-Barroso, Bogaerts, Garcia-Porta, Escoriza, Arribas, El Mouden, and Carranza, 2013 (1 sp.)	Tiznit toad; Brongersma's toad	1
Blythophryne Chandramouli et al., 2016[6]	Andaman bush toads	1
Bufo Garsault, 1764	Toads	18
Bufoides Pillai & Yazdani, 1973	Mawblang toads; Rock toads	2
Bufotes Rafinesque, 1815	Palearctic green toads	15
Capensibufo Grandison, 1980	Cape toads	5
Churamiti Channing & Stanley, 2002		1
Dendrophryniscus Jiménez de la Espada, 1871	Tree toads	16
Didynamipus Andersson, 1903	Four-digit toad	1
Duttaphrynus Frost et al., 2006	Dutta's toads	27
Epidalea Cope, 1864	Natterjack toad	1
Frostius Cannatella, 1986	Frost's toads	2
Ghatophryne Biju, Van Bocxlaer, Giri, Loader, and Bossuyt, 2009		2
Incilius Cope, 1863	Central American toads; Middle American toads; Cerro Utyum toads	39
Ingerophrynus Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006	Hainan toads	12
Laurentophryne Tihen, 1960	Parker's tree toad	1
Leptophryne Fitzinger, 1843	Indonesia tree toads	3
Melanophryniscus Gallardo, 1961	South American redbelly toads	29
Mertensophryne Tihen, 1960	Snouted frogs	14
Metaphryniscus Señaris, Ayarzagüena & Gorzula, 1994		1
Nannophryne Günther, 1870		4
Nectophryne Buchholz & Peters, 1875	African tree toads	2
Nectophrynoides Buchholz & Peters, 1875	African live-bearing toads	13
Nimbaphrynoides Dubois, 1987	Nimba toads	1
Oreophrynella Boulenger, 1895	Bush toads	8
Osornophryne Ruiz-Carranza & Hernández-Camacho, 1976	Plump toads	11
Parapelophryne Fei, Ye & Jiang, 2003		1
Pedostibes Günther, 1876	Asian tree toads	1
Pelophryne Barbour, 1938	Flathead toads	13
Peltophryne Fitzinger, 1843	Caribbean toads	14
Phrynoidis Fitzinger in Treitschke, 1842	Rough toads	2
Poyntonophrynus Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006	Pygmy toads	11
Pseudobufo Tschudi, 1838	False toad	1
Rentapia Chan, Grismer, Zachariah, Brown, and Abraham, 2016		2
Rhaebo Cope, 1862	Cope toads	13
Rhinella Fitzinger, 1826	Beaked toads	92
Sabahphrynus Matsui, Yambun, and Sudin, 2007	Sabah earless toad	1
Schismaderma Smith, 1849	African split-skin toad	1
Sclerophrys Tschudi, 1838		44
Sigalegalephrynus Tschudi, 1838	Puppet toads	5
Strauchbufo Fei, Ye, and Jiang, 2012	Siberian toad; Mongolian toad	1
Truebella Graybeal & Cannatella, 1995		2
Vandijkophrynus Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006	Van Dijk's toads	6
Werneria Poche, 1903	Smalltongue toads	6
Wolterstorffina Mertens, 1939	Wolterstorff toads	3
Xanthophryne Biju, Van Bocxlaer, Giri, Loader & Bossuyt, 2009		2
"Bufo" hadramautinus Cherchi, 1963	Suia Hadramaut toad
"Bufo" scorteccii Balletto and Cherchi, 1970	Scortecci's toad

References

1. Zweifel, Richard G. (1998). Cogger, H.G.; Zweifel, R.G. (eds.). Encyclopedia of Reptiles and Amphibians. San Diego: Academic Press. pp. 91–92. ISBN 978-0-12-178560-4.
2. "The IUCN Red List of Threatened Species". IUCN Red List of Threatened Species. Retrieved 2019-01-19.
3. Brown, Federico D.; Del Pino, Eugenia M.; Krohne, Georg (December 2002). "Bidder's organ in the toad Bufo marinus: Effects of orchidectomy on the morphology and expression of lamina-associated polypeptide 2". Development, Growth & Differentiation. 44 (6): 527–535. doi:10.1046/j.1440-169X.2002.00665.x. ISSN 1440-169X.
4. Vitt, Laurie J.; Caldwell, Janalee P. (2014). Herpetology: An Introductory Biology of Amphibians and Reptiles (4th ed.). Academic Press. p. 122.
5. Iskandar, D. T.; Evans, B. J.; McGuire, J. A. (2014). "A novel reproductive mode in frogs: a new species of fanged frog with internal fertilization and birth of tadpoles". PLoS ONE. 9 (12): e115884. doi:10.1371/journal.pone.0115884. PMC 4281041.
6. S. R. Chandramouli, Karthikeyan, Vasudevan, S Harikrishnan, Sushil Kumar Dutta, S Jegath Janani, Richa Sharma, Indraneil Das, Ramesh Aggarwal. “A new genus and species of arboreal toad with phytotelmonous larvae, from the Andaman Islands, India (Lissamphibia, Anura, Bufonidae)” ZooKeys (2016) 555: 57-90, https://doi.org/10.3897/zookeys.555.6522

• "Amphibian Species of the World 5.1 - Bufonidae". Archived from the original on 2012-07-15. Retrieved 2008-04-10.
• Stebbins, Robert. Western Reptiles & Amphibians (3rd ed.). Houghton Mifflin Co., 2003.
• Halliday, Tim R., and Kraig Adler (editors). The New Encyclopedia of Reptiles & Amphibians. Facts on File, New York, 2002.

External links

• Tolweb.org: Bufonidae
• Bufonidae.com
• Amphibian and Reptiles of Peninsular Malaysia - Family Bufonidae
• FED.us
• Bufonidae recordings from the British Library Sound Archive