Toads

The appearance and size of the toads vary greatly. The body length ranges from 20 mm ( Guiana harlequin ) to 250 mm ( Blomberg toad ) ^[2] . The body is usually wide, overweight, limbs short ^[3] . Ribs are missing. The skin is usually dry to the touch, thick, often covered with numerous smooth or sharp tubercles-warts of different sizes ^[4] . The language is narrow, big. The teeth, in most cases, are partially or completely reduced . The pupil is horizontal, the fingers of the hind limbs are partially connected by the swimming membrane ^[5] . The transverse processes of the sacral vertebra are not expanded into discs ^{[6] [7]} .

Parotid glands ( parotids ), which are absent in a number of tropical forms, are clearly visible behind the eyes. These glands contain alkaloid poison - bufotoxin , which toads secrete during stress. The composition and proportions of the poison in different species vary ^[8] . The poison of some toads (for example, Colorado toad ) is used as a recreational psychotropic agent ^[9] .

In males of the family, Bidder's unique neotenic organ is present - a rudimentary ovary , which develops on the front edge of larval testes and can persist in many adult amphibians ^[10] . Under certain conditions, the organ becomes an active ovary, and the male, in fact, becomes a female ^[11] .

Toads are night terrestrial amphibians that enter the water only for laying eggs, but there are also semi-aquatic species (for example, ansonia ) and arboreal ( tree toads ). They hibernate in the ground. They feed exclusively on small invertebrates : insects , worms and snails . Useful extermination of agricultural pests ^[12] .

Most species are characterized by external fertilization , but some by internal fertilization ( Nectophrynoides , Mertensophryne micranotis ). Reproduction methods are different - from laying eggs in the water and the subsequent release of free-floating larvae from it, to egg-laying and direct surface development ^[13] . Most members of the family spawn in stagnant or flowing waters. Philippine toads of the genus Pelophryne lay eggs in the axils of the leaves at a height of several meters. Tadpoles of some species living in fast-flowing streams ( Ansonia , Atelopus ) develop abdominal suckers, with the help of which they are attached to underwater objects ^{[14] [3]} .

Distributed everywhere, with the exception of the Arctic , Antarctic , Greenland , Madagascar , New Zealand and many islands of the Pacific Ocean ^[15] . Toad-aga imported from America lives in Australia and Guinea ^[16] .

In Russia, only representatives of the genus Bufo are common, only 6 species: common , Caucasian , Far Eastern , green , reed and Mongolian toads ^[4] .

In European folklore, toads were associated with witches as familiars , sources of ingredients for magical potions, and sometimes had their own magical properties ^[17] . In iconography, the toad is an attribute of death or greed . In addition, the toad, devouring the genitals of a naked female figure, symbolizes lust ^[18] .

As of November 2018, the family includes 52 genera and 609 species ^[15] :

• Adenomus Cope, 1861 ( 2 species )
• Altiphrynoides Dubois, 1987 ( 2 species )
• Amazophrynella Fouquet et al. , 2012 ( 11 species )
• Anaxyrus Tschudi, 1845 ( 23 species )
• Ansonia Stoliczka, 1870 - Ansonia ( 33 species )
• Atelopus Duméril & Bibron, 1841 - Atelopes , or harlequins ( 96 species )

• Barbarophryne Beukema et al. , 2013 ( 1 view )

• Blythophryne Chandramouli et al. , 2016 ( 1 view )

• Bufo Garsault, 1764 - Toads ( 17 species )

• Bufoides Pillai & Yazdani, 1973 - Rock Toads ( 2 species )

• Bufotes Rafinesque, 1814 ( 16 species )

• Capensibufo Grandison, 1980 - Cape Toads ( 5 species )

• Churamiti Channing & Stanley, 2002 ( 1 view )

• Dendrophryniscus Jiménez de la Espada, 1870 - Wood Harlequins ( 10 species )

• Didynamipus Andersson, 1903 - Four-toed Toads ( 1 species )

• Duttaphrynus Frost et al. , 2006 ( 27 species )

• Epidalea Cope, 1864 ( 1 view )

• Frostius Cannatella, 1986 ( 2 species )

• Ghatophryne Biju et al. , 2009 ( 2 types )

• Incilius Cope, 1863 ( 39 species )
• Ingerophrynus Frost et al. , 2006 ( 12 species )

• Laurentophryne Tihen, 1960 - Laurent toads ( 1 species )

• Leptophryne Fitzinger, 1843 - Subtle Toads ( 3 species )

• Melanophryniscus Gallardo, 1961 - Black - backed ( 29 species )
• Mertensophryne Tihen, 1960 - Mertens toads ( 14 species )

• Metaphryniscus Señaris et al. 1994 ( 1 view )

• Nannophryne Günther, 1870 ( 4 species )

• Nectophryne Buchholz & Peters, 1875 - Climbing toads ( 2 species )

• Nectophrynoides Noble, 1926 - Viviparous toads ( 13 species )
• Nimbaphrynoides Dubois, 1987 ( 1 view )
• Oreophrynella Boulenger, 1895 - Guiana harlequins ( 9 species )
• Osornophryne Ruiz-Carranza & Hernández-Camacho, 1976 - Fat Harlequins ( 11 species )

• Parapelophryne Fei, Ye & Jiang, 2003 ( 1 view )

• Pedostibes Günther, 1876 - Tree toads ( 1 species )
• Pelophryne Barbour, 1938 - Toads ( 12 species )
• Peltophryne Fitzinger, 1843 - Caribbean toads ( 12 species )

• Phrynoidis Fitzinger, 1842 ( 2 species )

• Poyntonophrynus Frost et al. , 2006 ( 11 species )

• Pseudobufo Tschudi, 1838 - Water toads ( 1 species )

• Rentapia Chan at al., 2016 ( 2 species )

• Rhaebo Cope, 1862 ( 13 species )

• Rhinella Fitzinger, 1826 ( 92 species )

• Sabahphrynus Matsui, Yambun & Sudin, 2007 ( 1 view )

• Schismaderma Smith, 1849 - Red toads ( 1 species )

• Sclerophrys Tschudi, 1838 ( 45 species )

• Sigalegalephrynus Smart et al. , 2017 ( 2 types )

• Strauchbufo Fei, Ye & Jiang, 2012 ( 1 view )

• Truebella Graybeal & Cannatella, 1995 ( 2 species )

• Vandijkophrynus Frost et al. , 2006 ( 5 species )

• Werneria Poche, 1903 - Verneria ( 6 species )

• Wolterstorffina Mertens, 1939 - Volterstorff toads ( 3 species )

• Xanthophryne Biju et al. , 2009 ( 2 types )

Species of incertae sedis

• Bufo hadramautinus Cherchi, 1963 - South Arabian toad
• Bufo scorteccii Balletto and Cherchi, 1970 - Yemeni toad

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  American toad

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  Amazon harlequin

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  Caribbean toad

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  Red toad