Megophrys nasuta

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Geographic Range

Megophrys nasuta can be found on the forest floors of Southeast Asia, from the foothills of the Himalayas to the Indo-Australian Archipelogo (Obst et. al, 1984).

Habitat

Megophrys nasuta prefer a spacious, permanently damp and relatively cool environment. Their optimal temperature is between 22 -24 degrees C. They can be found on the rain forest floors, usually near small streams (sci-ctr.edu 1996). They are known to use both land and water areas extensively (Bartlett 1996).

Physical Description

Megophrys nasuta is an animal perfectly designed to fit its surroundings. They are attractive however modestly colored. Hidden dorsally in grays, tans, russets, or browns which become darker laterally, they are almost invisible among the forest leaf litter (Bartlett 1996). Their smooth skin is modified so that they resemble dead leaves on the forest floor. A huge angular head with supraciliary projections above each eye

and nasal area, along with its cryptic coloration cause it to resemble dry leaves. Skin folds from above the eye to the tympanum and shoulders; and toes which are only webbed at the bases, also contribute to their leaf-like appearance (Obst et. al 1984). Males are often substantially smaller than females, rarely more than half their size. Females usually attain just over 5 inches (12.7cm) in length (sci-ctr.edu 1996). Using its leaf-like appearance for camouflage, Megophrys nasuta is virtually undetectable in the leaf litter of the forest floor unless it moves.

Development

Reproduction

Little information is available on the natural breeding of these frogs, however captive reproduction is fairly common. They are oviparous with the females attaching the egg clusters to the underside of rocks and logs which are water swept and are partially or entirely submerged. If the eggs are attached to surfaces in water the tadpoles hatch and begin life in their aquatic habitat. However if the eggs are laid partially submerged, the eggs slide down to the water on threads of thin, gelatinous egg coverings. The eggs are large and relatively few in number (Bartlett 1996). The larvae are elongated , with a very large , funnel - shaped mouth. They cling with their mouths at the surface while their body hangs vertically. This helps them in their feeding strategy which is specialized

on microorganisms at the waters surface (Obst et. al 1984).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)

Behavior

Megophrys nasuta is a secretive anuran. It hides among the leaf-littered ground motionless until an unsuspecting prey item passes by. They then are explosive attackers, jumping onto the prey and immediately engulfing it. Adding to the secretive nature is their call. It is soft "Ching!" which is produced only as a single note, and stops at the slightest disturbance (Mattison 1987).

Food Habits

Megophrys nasuta is a ferocious predator. It uses it's cryptic coloration and unusual appearance to prey on a wide variety of unsuspecting animals on the forest ground. Typically they feed on arachnids, nestling rodents, lizards and other frogs (Obst et. al 1984). Aside from these usual prey items, they are also partial to crabs and scorpions, which happen to be their main source of food (sci-ctr.edu 1996).

Conservation Status

Status: no special status, however it is threatend by loss of habitat, and overexploitation by the exotic pet trade (sci-ctr.edu 1996).

Other Comments

Megophrys nasuta is a member of the superfamily Megophryid in the family Pelobatidae. This is the largest and most diverse family-level group of non-neobatrachian frogs. All megophryids for which data are available have unusually ossified intervertebral disks, and hyoid plates that lack most of the ceratohyals. For this reason there are no known fossils (sci-ctr.edu 1996). This animal is a perfect example of why scientific names are so important. This frog is known by several common names which such as, 1) Asiatic Horned Toad, 2) Malayan Horned Frog, 3) Malaysian Leaf Frog, 4) Asian Spadefoot Toad , just to name a few. Without the designation of a single scientific name it would be next to impossible to collate knowledge of this species.

Contributors

Todd Mexico (author), Michigan State University, James Harding (editor), Michigan State University.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

References

Bartlett, R., P. Bartlett. 1996. Frogs, Toads and Treefrogs. Hauppauge, NY: Barron's educational series, Inc..

Mattison, C. 1987. Frogs & Toads of the World. New York, NY., Oxford, England: Facts on File Publications.

Obst, F., K. Richter, U. Jacob. 1984. Atlas of Reptiles and Amphibians for the terrarium. Neptune, City, NJ: T.F.H., Publishing, Inc..

Virtual Science Centre Project, .. 1996. "Endangered vertebrates of Singepore" (On-line). Accessed December 7, 1999 at http://sci-ctr.edu.sg/ssc/imglib/vertebra/megophry.html.