Many examples of crypsis, the ability to avoid observation, are within the various taxa of the order Anura, but perhaps none are more spectacular than that of the Malaysian horned frog (Megophrys nasuta
Several anatomical characteristics make Malaysian horned frogs look similar to large leaves. The body is dorsoventrally flattened, and the head is adorned with three fleshy projections. One protrudes from the rostrum, and one is over each eye. Two sets of dorsolateral folds running from the shoulder to the groin and a variable number of dorsum tubercles further breaks up the form. Dorsal coloration is typically a shade of either red or brown, and often darker reticulations similar to the veinlike pattern of a leaf are present. Although some animals have a deep-orange or red throat, it is usually dark brown with lighter shades of brown, gray or white, giving the appearance of a shadow. The belly is whitish or light gray.
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Malaysian horned frogs (Megophrys nasuta).
Malaysian horned frogs show a high degree of sexual dimorphism. Females grow to approximately 71/3; inches long, and males attain a maximum length of a little more than 4 inches.
Malaysian horned frogs are generally rewarding captives, though maintaining the species long term and achieving captive reproduction can prove challenging. As with all reptiles and amphibians, purchasing a healthy individual is key.
The Malaysian horned frog is rarely bred in captivity, and most frogs currently available in the hobby are wild-caught. Reptile exporters in Malaysia often pack large numbers of frogs in the same container, which can predispose these animals to stress and infectious conditions. When the frogs arrive in the United States, they are often placed in overcrowded holding containers, compounding the stress and further weakening the amphibians’ immune systems.
Seek dealers mindful of overcrowding. If you’re dealing with someone through the Internet or over the phone, ask how the Malaysian horned frogs are housed at the facility. If you can observe the frogs in person, look for frogs housed individually in reasonably sized containers. On examination, look for eye clarity, and try to find active animals that do not appear emaciated or weak. After the purchase, try to get the animal set up as soon as possible, and keep the number of additional animals in the same enclosure to a minimum.
Keeping It Simple
There are a number of ways to house the Malaysian horned frog. During the acclimation period, select a simple setup that is easily cleaned. I prefer 66-quart Sterilite storage containers with opaque or solid sides. These help minimize stress in new individuals and help prevent rubbing against the sides, which can damage the amphibians’ fleshy “horns.”
One of my female Malaysian horned frogs developed abrasions over the horns. They became infected, and this delicate tissue was almost completely gone by the time the infection was under control. Using opaque-sided containers has eliminated these issues in my experience.
I have used moist paper towels as a substrate for years with no adverse effects. I also provide a shallow water bowl approximately 8 inches in diameter and 1 inch deep, so the Malaysian horned frogs can thoroughly soak in the evening. An alternative approach is to use a 2- to 3-inch layer of foam rubber on half of the enclosure and fill the other half with water to a level midway up the foam.
Lighting is an important concern for the care of Malaysian horned frogs. Appropriate light sources include UVB-emitting fluorescent tubes or compact fluorescents. Providing a source of UVB light allows many herps to naturally produce Vitamin D3, but generally this is not considered necessary to the health of amphibians that receive a Vitamin D3 supplement.
As with any amphibian, keeping the cage and the water bowl clean at all times is important. A frog’s permeable skin makes it highly sensitive to infection. I typically clean a simple enclosure once weekly.
Megophrys nasuta prefers moderate temperatures, typically in the range of 70 to 78 degrees Fahrenheit, and a humidity of 60 to 80 percent.
Designing a streamside naturalistic terrarium is an alternative approach to a simple enclosure. My Malaysian horned frog cages measure 45 inches long, 17 inches wide and 18 inches tall. Excessive height is not necessary because these animals are primarily terrestrial and rarely climb.
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TMalaysian horned frogs can be explosive eaters, so the author feeds them in a simple feeding setup to prevent substrate ingestion.
The “horn” protects the eye of this adult female Malaysian horned frog when it feels threatened, and it breaks up the frog’s form, so the amphibian more closely mimics a leaf on the forest floor.
Naturalistic terraria have worked well for trios of two male Malaysian horned frogs and one female Malaysian horned frog, but a smaller terrarium is suitable for an individual or a pair. A 20-gallon breeder terrarium is a good starting point for a pair because it provides a larger footprint than a traditional 20-gallon terrarium. A good rule of thumb is to add 5 gallons of space per additional frog, but a larger cage is always better for these large, easily stressed frogs.
I use a false-bottom setup consisting of egg-cratelike material used in packaging fluorescent lighting fixtures. This material covers approximately half of the Malaysian horned frog terrarium base. Appropriately sized panels are pieced together with small cable ties to make a box. This acts as the drainage layer. The egg-cratelike material is overlaid with fiberglass screen, which prevents soil from falling through into the false-bottom area and thus impeding drainage.
Many substrates, including crushed coconut coir, sphagnum moss or natural soil, can be used. I use a modified version of the Atlanta Botanical Gardens mix. Two parts of a coco-fiber and orchid bark mix are combined with one part of an activated charcoal and peat moss mix. I leave out the two parts of crushed tree-fern fiber described by the Atlanta Botanical Gardens because this item may potentially harm Malaysian horned frog’s gastrointestinal tract.
Water 2¾ inches deep fills the space uncovered by egg-cratelike material. Filtered spring water, water aged in an open container for 24 hours, or water dechlorinated with AmQuel or a similar aquarium product are good water options.
A 3-inch-tall glass panel divides the land and water sections. It supports the substrate and prevents it from falling into the water section. An alternative approach to a glass barrier is to use large-grade aquarium gravel as the land section drainage layer. This eliminates the need for a glass divider and a false-bottom setup, which can be difficult to install and maintain.
Select hardy plants to add cover for the Malaysian horned frogs. Appropriate examples include Scindapsus and Philodendron species, and the bird’s nest fern (Asplenium nidus). Appropriate UV lighting, though not considered necessary for the health of amphibians, is required for the health of the plants in naturalistic vivaria. Next Page>>
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