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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Southeast Asian Toad

Synonyms and Other Names: Asian black-spined toad, Asian common toad, formerly Bufo melanostictus

Taxonomy: available through www.itis.gov

Identification: Boulenger (1890) describes this species as having a head with bony ridges, no tarsal fold, and a tympanum at least two thirds the diameter of the eye. The toes are at least half webbed. The body is yellowish or brown dorsally with the ventral surface spotted to some degree. The upper surface of the body has spiny, black-tipped warts with very prominent kidney-shaped parotoid glands that exude toxin (Mo 2017).

Native Range: Widely distributed in South Asia. The Southeast Asian toad occurs from northern Pakistan through Nepal, Bangladesh, and India including the Andaman and Nicobar Islands, Sri Lanka, Myanmar, Thailand, Laos, Vietnam, Cambodia and southern China, Taiwan, Macau to Malaysia, Singapore, and the Indonesian islands of Sumatra, Java, Borneo, Anambas and Natuna Islands. It was introduced to the islands of Bali, Sulawesi, Ambon and Manokwari, and the northeastern portion of the Vogelkop Peninsula in New Guinea (Krysko et al. 2011, EOL 2012).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Duttaphrynus melanostictus is a dietary generalist. Adults feed primarily on invertebrates including ants, termites, beetles, grasshoppers, and spiders (Döring et al. 2017) while tadpoles feed on plankton, leaves, eggs, detritus, and other tadpoles (Mahapatra 2017). O’Shea et al. (2013) noted the blindsnake Ramphotyphlops braminus, as prey.

Female D. melanostictus mature at a larger body size and have an overall larger body size than males (Ngo and Ngo 2013). This species breeds in a wide range of habitats from temporary to permanent pools as well as slow-flowing streams and canal systems (Mahapatra et al. 2017). Breeding coincides with heavy rainfall from Feb-May (Kharkongor and Hooroo 2017). Rout et al. (2017) found the preferred breeding habitat is slightly acidic, shallow, and contains moderate submerged aquatic vegetation. The eggs are laid in clutches on various substrates from sand, gravel, roots, and rocks, to submerged vegetation (Rout et al. 2017). Tadpoles demonstrate developmental plasticity under stressful environmental conditions and can accelerate metamorphosis, compromising body size at metamorphosis for a better chance at survival to adulthood (Mogali et al. 2017).

Means of Introduction: Hitchhiker in cargo (Krysko et al., 2011).

Status: Failed

Impact of Introduction: On the island of Timor-Leste near Indonesia toad predators including the Green pit viper Trimesurus insularis and the Timor monitor lizard Varanus timorensis, have reportedly declined since the arrival of the toad (Trainor 2009). Within the invaded range, a lack of knowledge of the toad’s toxicity has led to the death of one child and several adults becoming sick after eating this species (Trainor 2009).

Remarks: Duttaphrynus melanostictus has been observed exhibiting Davian behavior, attempting to copulate with a dead conspecific. A male toad was observed in amplexus with a road-killed female in western India (Patel et al. 2016).

In its native range there is some evidence that a native predator, the Small-banded Kukri Snake Oligodon fasciolatus, has found a way to circumvent the toxic secretions of the parotid glands (Bringsøe et al. 2020).

References: (click for full references)

Bringsøe, H., M. Suthanthangjai, W. Suthanthangjai, and K. Nimnuam. 2020. Eviscerated alive: Novel and macabre feeding strategy in Oligodon fasciolatus (Günther, 1864) eating organs of Duttaphrynus melanostictus (Schneider, 1799) in Thailand. Herpetozoa 33:157-163.

Boulenger, G.A. 1890. The Fauna of British India, including Ceylon and Burma: Reptilia and Batrachia. Taylor and Francis, London, United Kingdom.

Döring, B., S. Mecke, M. Kieckbusch, M. O’Shea, and H. Kaiser. 2017. Food spectrum analysis of the Asian toad, Duttaphrynus melanostictus (Schneider, 1799) (Anura: Bufonidae), from Timor Island, Wallacea. Journal of Natural History 51:607-623.

EOL. 2012. "Bufo melanostictus." Encyclopedia of Life, available from http://eol.org/pages/1039118/details. Accessed 8 August 2012.

Krysko, K.L. and 12 others. 2011. Verified non-indigenous amphibians and reptiles in Florida from 1863 through 2010: Outlining the invasion process and identifying invasion pathways and stages. Zootaxa 3028:1-64.

Mahapatra, S., S.K. Dutta, and G. Sahoo. 2017. Opportunistic predatory behaviour in Duttaphrynus melanostictus (Schneider, 1799) tadpoles. Current Science 112:1755-1759.

Kharkongor, M. and R.N.K. Hooroo. 2017. Microscopic studies on the effects of cholopyrifos on the erythrocytes of Duttaphrynus melanostictus (Schneider, 1799) tadpoles and its physiological significance. Pranikee - Journal of Zoological Society of Orissa 29:15-25.

Mo, M. 2017. Asian black-spined toads (Duttaphrynus melanostictus) in Australia: An invasion worth avoiding. IRCF Reptiles and Amphibians 24:155-161.

Ngo, B.V. and C.D. Ngo. 2013. Reproductive activity and advertisement calls of the Asian common toad Duttaphrynus melanostictus (Amphibia, Anura, Bufonidae) from Bach Ma National Park, Vietnam. Zoological Studies 52:12.

O’Shea, M., A. Kathriner, S. Mecke, C. Sanchez, and H. Kaiser. 2013. ‘Fantastic Voyage’: a live blindsnake (Ramphotyphlops bramis) journeys through the gastrointestinal system of a toad (Duttaphrynus melanostictus). Herpetology Notes 6:467-470.

Patel, H., P. Vaghashiya, and S.K. Tank. 2016. Necrophiliac behavior in the Common Asian Toad, Duttaphrynus melanostictus (Schneider 1799) in western India. IRCF Reptiles and Amphibians 23:32-33.

Rout, J., S. Mahapatra, and G. Sahoo. 2017. Breeding activities of the Asian common toad (Duttaphrynus melanostictus) in Jagatsinghpur district, Odisha, India. Pranikee - Journal of Zoological Society of Orissa 29:33-40.

Trainor, C.R. 2009. Survey of a population of black-spined toad Bufo melaonstictus in Timor-Leste: confirming identity, distribution, abundance and impacts of an invasive and toxic toad. Charles Darwin University, Alice Springs, Australia.

Other Resources:
US Fish and Wildlife Service Ecological Risk Screening Summary for Duttaphrynus melanostictus

Author: M.E. Brown and P. Fuller

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.