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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, China, Hong Kong, India, Indonesia, Lao
People's Democratic Republic, Malaysia, Myanmar, Nepal,
Pakistan, Sri Lanka, Taiwan, Province of China, Thailand,
Vietnam.
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.
Comments:
In
Pakistan this toad is a highland form, does not extend in
the Indus Valley.
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
Reference:
None
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