Vietnamese Mossy Frog

Tonkin Bug-eyed Frog

Theloderma corticale

Description

Vietnamese mossy frogs are undoubtedly one of the most beautiful and unusual of frogs currently available in the pet community. They were first described in 1903, but were only recently “rediscovered,” with more extensive surveying taking place in the mid to late 1990s. They are a medium to large sized tree frog with heavily tubercled skin mottled in pink or red, green, grey, black and yellow. The blend of these colors gives them a moss-like appearance from which their common name is derived. They have highly reticulated gold-green eyes. Their overall appearance is quite alien and can be said to resemble Godzilla. They are primarily nocturnal, semi-aquatic and spend much of their time partially submerged with only their head protruding in the shallow water that accumulates in tree or cliff niches, epiphytes or natural depressions. They grow to nearly 3.5 inches (9 centimeters) in length and can live for at least 5 years.

Natural Habitat

Vietnamese mossy frogs as the name implies are endemic to Vietnam or more specifically, the Hoang Lien Son mountain range northeast of Hanoi and Mao-Son Mountain in the northeast near the Chinese border. They may have a wider range within Vietnam, and may also extend into southern China. Within this mountainous region they are found at relatively high altitudes of around 3000 feet in karst zones; areas characterized by steep limestone cliffs and rocky outcroppings surrounded by or embedded in primary evergreen forest. Although the climate is fairly pleasant in and around these locations (Hanoi and Cao Bang enjoy mild and pleasant climates year round), the elevation and harsh terrain in which Vietnamese mossy frogs are found demonstrates their adaptability and hardiness. As such, we have found that these frogs are less susceptible to temperature changes than water quality. In their natural habitat they are known to withstand temperatures in the 40s Fahrenheit, but extremes of this nature are not recommended in captivity.

Artificial Habitat

Vietnamese mossy frogs do best in a heavily planted, vertically oriented, semi-aquatic enclosure with subtle filtration. The water may be filtered using an internal power filter (Fluval. Eheim, etc) or via an air powered sponge filter. Driftwood, cork bark, hollow logs, ceramic pots, rocks, and other suitable materials should be used to provide nooks for the frogs to hide in. Emergent rocks, logs, etc. should be used to provide some terrestrial habitat. Mossy frogs are not very migratory, and subsequently do not require large enclosures. A 10-18 gallon aquarium is sufficient for 1-3 young frogs. A 30 gallon tank is spacious enough for a pair of adults. Water should be from a clean source, and conditioned with a commercially available water conditioner to remove chlorine and chloramines. Adding Indian almond leaves Terminala cattapa to the water will increase tannic acid content and reduce chances of fungal and bacterial problems. Partial (~25%) water changes should be performed every two weeks, approximately (the frequency will vary depending on the system and bioload). The addition of aquatic plants and hydroponic terrestrials also provide additional biological filtration as well as hiding spaces. A portion of the top may be covered to increase humidity to a moderate level. They will do best if given a moisture gradient -- some areas in the enclosure should be dryer and well ventilated, others more humid and damp. This species does well with water temps in the mid 70s F. If necessary the water can be heated using an aquarium heater to maintain temperatures of 74-77 F degrees. Ideal ambient air temps are 70-77 F during the day, with nighttime temperatures dropping 5-10 degrees Fahrenheit. Although mossy frogs do not seem to require UV lighting, the live plants in the enclosure will benefit from full spectrum lighting, at a photoperiod of 10 - 12 hours a day.

Diet

Vietnamese mossy frogs are enthusiastic eaters, particularly if fed at dusk. They do well on a diet of crickets, roaches, and other small invertebrates. They should be fed three to four times a week; 4-6 prey items per frog. Insect prey should be dusted with a quality calcium and mineral and vitamin supplements every other feeding.

Caveats

Vietnamese mossy frogs are a shy, retiring, observation-only type of frog. They generally will not do well in a situation without adequate shelters and hiding spaces or if handled frequently. Provided they are given clean, conditioned water and a good diet they are hardy and trouble-free frogs and a fantastic dislay species. Enclosures may be designed to sustain the complete life cycle, with breeding adults, eggs, tadpoles, and metamorphs all in view.