|
| FACT FILE: |
| Local
Name: |
Unknown |
| Family: |
RANIDAE |
| Genus: |
Euphlyctis |
| Status: |
Abundant |
| Warning: |
None |
|
|
|

Photo Credit: Dr. Muhammad Sharif Khan | |
Description
and Biology:
The
interorbital space is narrower than the upper eyelid; tympanum is
distinct, about two third the size of the eye; fingers slender, pointed
or slightly swollen at the tips, first not extending beyond second; toes
are completely webbed; inner metatarsal tubercle long, conical much like
a rudimentary toe; male with vocal slits under the lower jaw; dorsum
with numerous scattered small smooth tubercles, sides of body rugose,
ventrum smooth..
Color:
Dorsum light gray, olivegreen or light brown, sometimes black, with
irregular black spots. Thighs posteriorly dark with one or two yellow or
white irregular longitudinal stripes; ventrum white, immaculate or with
dark speckling or reticulation; vocal sacs light brown.
Tadpole:
Tadpole
large, with oval bulging body, broadest at midbody, venter flat. The
eyes are large and lateral. Tail is long, muscular, with wider dorsal
and narrower ventral fins, tail tip is obtuse.
The
anteroventral oral disc has broad anterior labium with a single tooth
row, posterior labium is narrower with two rows of teeth. The labial
tooth row formula is 1/2 (Figure 6B). The teeth are arranged in a single
row. A tooth is a squarish, medially curved 0.13-0.34 mm long, blunt
tipped rod. The beak is broad, finely serrated. A pair of lateral thick
labial palps, with blunt, cut into short papillae. The posterior labial
palp extends well beyond posterior labium, is narrowly interrupted
medially, while its anterior half forms an outpocket to include a patch
of smaller papillae. Dorsum of tadpole blackish with dark black blotches
and spots extending onto tail and fins (Khan 1982a, 1991a). Total length
of the tadpole 42-44 mm, tail 23-24 mm. This tadpole remains solitary,
stays most of the time at the bottom, feeds mostly on debris, almost
clogging its digestive tract. Usually no fresh vegetation is detected in
its digestive tract. It also feeds on dead tadpoles, drowned animals
like earthworms, etc. It attacks sympatric tadpoles and feeds on them
(Khan and Mufti 1995).
Euphlyctis
cyanophlyctis tadpoles are most common in water bodies throughout
the plains of Punjab and Sindh, from late February to mid-September.
Biology:
This
frog has a peculiar
unique habit of skittering over the water surface, that has been
reported by the Mogul Emperor Babar in his autobiography (Beveridge
1979; Khan and Tasnim, 1987).
The frog
either floats or remains squatting in the vegetation along marginal
water. An intruder initiates the frog’s skipping behavior during which
the flattened and inflated ventral surface of the body rests on the
water surface while the push comes from the completely distended webbed
feet which steer the body forward so that the frog is speedily carried
to the center of the pond. When further provoked, it plunges into the
depths.
The frog
can tolerate a wide range of pH variations, from fresh water to
considerably brackish and polluted refuse water; it thrives equally well
in sewer systems of towns and cities.
Individual
frogs call from permanent water bodies almost throughout the year.
However, active breeding activity is initiated as early summer water
temperature rises to 10-12oC (Khan and Malik 1987b). The calling males
usually gather in a corner of a pond with some marginal vegetation. Some
sit on the moist margin others float. The tone of call is very variable,
depending on water and atmospheric temperatures, and the age and
breeding state of the frogs. It is just "chuutt, chuutt, chuutt"
repeated several times. Calling males are very active, calling and
squeaking and continuously jumping over each other, causing commotion in
the pond water. They actively assault each other in reproductive frenzy.
When a pair is formed it does not leave the site. A female may pair with
several males, laying eggs with each.
In
Balochistan Euphlyctis cyanophlyctis breeds sympatrically with Paa
sternosignata, and in northern hilly tracts with Tomopterna
breviceps. Often its relatively active males pair with relatively
docile frogs of these species. No eggs are known to result from such
pairings (Khan 1987; Khan and Ahmed 1987).
Euphlyctis
cyanophlyctis is a voracious feeder, feeding mostly on aquatic
insects, beetles, tadpoles, dragonflies, grasshoppers, fry, etc. It is
pest exterminator, feeds voraciously on different insects and their
larvae. It is known to come out of the water during the night and go
foraging in the surrounding grass, returning to the pond at dawn.
Karyotype
number recorded for this species is 26 (Yadav and Pillai 1975).
Habitat,
Distribution
and Status:
Euphlyctis
cyanophlyctis is a highly aquatic and littoral frog. It remains
permanently resident in different types of habitats with pooled water,
in the plains and submountainous parts of Pakistan. The frog is
remarkably capable of adjusting itself to the uncertain aquatic
conditions in temperate arid parts of Pakistan.
The
common skittering frog is one of the most widely distributed Oriental
frogs. It extends from Thailand to Nepal, throughout India, Sri Lanka,
almost throughout Pakistan below 1800 m (Khan, 1997). It extends
westwards to Iran and Afghanistan. Nikolsky (1900) described R.
c. siestanica from southern Afghanistan, while Peter (1863)
describes its Saudi Arabian population as a distinct species Euphlyctis
ehrenbergii. Recently Khan (1997) described a spinulate race E.
c. microspinulata of this frog from northwestern tableland of Hindukush
and Balochistan.
Though
the frog is very common in every type of small or large water bodies,
the pollutants in water do affect the frog. Either adults are killed or
migrate to new ponds. However, tadpoles and eggs perish. The frog and
its tadpoles are common in the diet of herons and other water visiting
birds. It is included in the dietary of several common snakes, varanids
and crocodiles. drainage of wetlands large affect the distribution of
this frog.
In
its wide range from Arabia to Thailand, this frog is distinguished in
several races:
Seistan:
E. c. seistanica Nikolskii, 1899
Sri Lanka: E. c. typus De Silva, 1958
E. c. fulvus De Silva, 1958
E. c. flavens De Silva, 1958
Northwestern Puinjab, Balochistan & Afghanistan: E. c.
microspinulata Khan, 1997.
Arabia: E. c. ehrenbergii Peters, 1863.
Possible
reasons for amphibian decline:
General
habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Urbanization
Prolonged drought
Drainage of habitat
Dams changing river flow and/or covering habitat
Subtle changes to necessary specialized habitat
Habitat fragmentation
Local pesticides, fertilizers, and pollutants
Long-distance pesticides, toxins, and pollutants
|

|
|
Euphlyctis
cyanophlyctis cyanophlyctis
( ) |
|
Map
Credit: Dr. Muhammad Sharif Khan |
References
and Credits:
-
Written
by M. S. Khan ([email protected]), Herp Lab, Rabwah, Pakistan
Edited by vtv (2002-05-24 )
-
AmphibiaWeb
database, University of California at Berkeley
( http://elib.cs.berkeley.edu/aw/index.html
)
-
Nausherwan
Ahmed