AMPHIBIAWEB
Duttaphrynus melanostictus
Southeast Asian Toad, Asian Common Toad, Spectacled Toad
family: Bufonidae

© 2013 Lars Fehlandt (1 of 51)

  hear Fonozoo call (#1)
  hear Fonozoo call (#2)
  hear Fonozoo call (#3)

View distribution map using BerkeleyMapper.


Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
See IUCN account.
CITES No CITES Listing
Other International Status Sotheast Asian common toad
National Status Common
Regional Status Rare alpine species

   

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Description
Head with distinct rostral, preorbital, supraorbital, postorbital and a short orbito-tympanic, cranial crests; no temporal ridge; interorbital space much broader than upper eyelid; tympanum very distinct, at least two third the diameter of the eye; first finger generally but not always extends beyond second; double subarticular tubercles only under third finger. Toes with single subarticular tubercle; parotid elipticle, with dark brown scattered branching concretions; skin heavily tuberculated on flanks, tubercles usually tipped with dark brown spines; a lateral dorsal staggered row of 8-9 enlarged tubercles; cranial crests, lips, digit tips, metacarpal and metatarsal tubercles are cornified with dark brown, which tend to peal off in preserved specimens; head is almost smooth.

Recently Khan (2001) has distinguished Pakistani population of this toad as a new subspecies Bufo melanostictus hazarensis, on the basis of kidney shaped parotid glands; double subarticular tubercles under penultimate phalanx of all fingers; rostral ridge absent from head; temporal ridge present; light brown dorsum.

It is the largest toad in Pakistan, female exceeds 150 mm in snout-vent length.

Color: Dorsum uniform gray of various shades, brown or reddish with dark spots, ventrum uniform dirty white, speckled with light brown on chin and throat.

The throat of breeding male is light orange or yellow. It develops cornified pads on inner side of first and second fingers.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Bangladesh, Bhutan, Brunei Darussalam, Cambodia, China, Hong Kong, India, Indonesia, Lao People's Democratic Republic, Malaysia, Maldives, Myanmar, Nepal, Pakistan, Singapore, Sri Lanka, Taiwan, Thailand, Viet Nam

Malaysian region distribution from AmphibiaWeb's database: Peninsular Malaysia, Sabah, Sarawak

View distribution map using BerkeleyMapper.
Until recently Bufo melanostictus was reported to as the common toad of Indo-Pakistan subcontinent (Günther, 1864; Murray, 1884; Boulenger, 1890; Annandale and Rao, 1918). However, in Pakistan, this toad is confined to District Hazara, Northwestern Frontier Province, Alpine Punjab and Azad Kashmir (Mertens, 1969a; Khan, 1972a).

Life History, Abundance, Activity, and Special Behaviors
Life history notes: A rare toad in Pakistan mostly confined to the low northern hilly ranges and Azad Kashmir. Nocturnal, appears soon after sunset; during day hides under stones, logs, piles of vegetation, holes and crevices among stones and in ground. Once a suitable place is selected, it is permanently shared with several toads.

The toad is lethargic timid animal. It moves about with deliberate hops from place to place in search of insects on which it feeds. In tropical southeast Asia it is most common amphibian, comes out after sunset in large numbers and frequents mostly the human habitations, where it congregate under street lamps to feed on photophilic insects (Church, 1960).

In temperate environs of western Himalayas, the breeding is initiated by the monsoon rains, from July to August. Males, gather in shallow side-pools along torrents and ponds. The call in low melodious "curr, curr, curr" repeated several times ending in a whistling note. The calling males become quite aggressive, tugging and jumping over each other, males for exceed female in numbers. It breeds in every available space containing some water from first showers of monsoon rains in the southern India (McCann, 1938). Males are much smaller than females. However, in tropical southeast Asia, the toad is known to breed throughout the year (Church, 1960).

Calling males occasionally jump over each other and try to secure a nuptial hold on each other, however, kicks and zestful wriggling dislodge them from each other and soon they resume calling. The females lurch round, as soon one comes close, a male jumps over it and quickly tightens it nuptial clasp, the other suitors are shaken off as the nuptial pair moves to a quitter place away from the site.

The eggs are laid in a double jelly string, generally in deep quieter water, where the egg-string is entangled in the vegetation or female moves round the submerged vegetation to wound the egg string round it. An egg is enclosed in a double gelatinous capsule (Khan, 1982b).

Tadpole: The tadpoles are uniform dark, inhabits side pools along hilly torrents, schools of them swarm along the marginal waters of ponds and puddles feeding on any type of algal material. The body is typically bufonid, globular with weak tail, dorsal fin is broad while ventral is narrow. The oral disc is typically bufonid, with 2(2)/3 labial tooth row formula, the oral papillae are lateral. The beak is finely serrated and sharp (Khan, 1991a).

Total length of tadpole 26-27 mm, tail 19-20 mm.

The swarms of recently metamorphosed toadlets from synchronised pairings leave water, many fall pray to several kind of predators, while several are crushed under feet and passing traffic. Karyotype number recorded for this species is 22 (Nataranjan, 1953).

Trends and Threats
Species of rugged mountains. Breeds in paddy fields, where pollution by chemicals affect its eggs and larvae.

Relation to Humans
Exterminates crop pests and other insects.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Prolonged drought
Drainage of habitat
Local pesticides, fertilizers, and pollutants
Long-distance pesticides, toxins, and pollutants

Comments
In Pakistan this toad is a highland form, does not extend in the Indus Valley.

For photos of Bufo melanostictus, also known as Duttaphrynus melanostictus, adults and larvae and another species account, see www.frogsofborneo.org.

References
 

Church, G. (1960). ''The invasion of Bali by Bufo melanostictus.'' Herpetologica, 16(1), 15-21.  

Khan, M.S. (1982). ''Collection, preservation and identification of amphibian eggs from the plains of Pakistan.'' Pakistan Journal of Zoology, 14, 241-243.  

Khan, M.S. (1991). Morphoanatomical specialization of the buccopharyngeal region of the anuran larvae and its bearing on the mode of larval feeding. Unpublished Ph.D. dissertation, University of the Punjab, Lahore, Pakistan.  

Mertens, R. (1969). ''Die Amphibien und Reptilien West-Pakistans.'' Stuttgarter Beiträge zur Naturkunde, 197, 1-96.  

Natarajan, R. (1953). ''A note on the chromosomes of Cacopus systoma.'' Proceedings of the 40th Indian Science Congress, Part 3, 180-181.



Written by M.S.Khan (typhlops99 AT hotmail.com), Herp Lab, Rabwah-35460, Pakistan
First submitted 2000-08-30
Edited by JG (2010-03-16)



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Citation: AmphibiaWeb: Information on amphibian biology and conservation. [web application]. 2014. Berkeley, California: AmphibiaWeb. Available: http://amphibiaweb.org/. (Accessed: Sep 30, 2014).

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