Gilliard's wrinkle-faced frog

Geographical Origin and Habitat: Cornufer gilliardi is a terrestrial frog species native to New Britain Island, the largest island in the Bismarck Archipelago of Papua New Guinea. This species primarily inhabits tropical moist lowland forests and low-altitude montane forests. It lives in the lower forest layer, hidden among damp leaf litter, piles of decaying plant matter, and the base of epiphytic plants and low shrubs, where it finds the humid and cool microclimate essential for its survival.

Taxonomy and Genetics: Classified within the family Ceratobatrachidae, in the genus Cornufer. This species is part of an evolutionary radiation of Pacific frogs characterized by the loss of the aquatic tadpole stage. The genetics of Cornufer gilliardi reflect its ecological adaptation to the isolated island conditions of New Britain, developing advanced physiological mechanisms to prevent the desiccation of eggs deposited in terrestrial environments.

Behavior and Habits: It has strictly terrestrial habits and is predominantly nocturnal. During the day it remains inactive and hidden to reduce transcutaneous water loss, while at night it emerges to hunt and reproduce. Males begin to call after sunset, producing repetitive vocalizations to signal their presence and defend their territory. Swimming is almost non-existent and the species avoids open water bodies, preferring moist but well-drained ground.

Morphology: It exhibits a compact body and a relatively large head compared to the trunk. The distinguishing morphological feature is the skin of the back, which appears markedly wrinkled, rich in small tubercles and skin folds that improve camouflage on the forest floor. Adults are small to medium-sized, measuring between 2 and 3.5 centimeters. Coloration varies from dark brown to greyish-cream with olive shades, mimicking plant debris.

Terrarium Setup: Requires a terrarium with minimum dimensions of 45x45x45 cm (approx. 18x18x18 inches) for a pair or a small trio. It is essential to create a bioactive setup with a drainage layer at the bottom to prevent water stagnation in the soil. The ideal substrate is composed of terrarium soil mixed with coconut fiber, covered with a thick layer of dry leaves and mosses. Climbing branches, cork bark, and live plants (such as Ficus pumila or small ferns) provide excellent shelter.

Lighting and Heating: Lighting should be moderate. A 12-hour light-dark cycle is recommended using LED lights and a 2% or 5% UVB lamp for reptiles and amphibians. The optimal temperature must be maintained between 21°C and 25°C (70°F - 77°F) during the day. It does not tolerate high temperatures: values above 27°C (81°F) can cause severe heat stress and quickly lead to the death of the animals. A slight temperature drop at night is preferred.

Humidity and Hydration: Air humidity must be constantly very high, between 85% and 95%. Automatic or manual misting must be carried out once or twice a day with reverse osmosis water. The substrate must remain constantly moist but never soaked. It is advisable to provide a very shallow bowl of dechlorinated water, ensuring that the frogs can enter and leave without any difficulty to avoid the risk of drowning.

Feeding and Supplementation: Feeds exclusively on small live invertebrates. In captivity, the ideal diet consists of fruit flies (Drosophila melanogaster and hydei), micro-crickets, springtails, dwarf isopods, and small silkworms. The food must be dusted regularly with pure calcium and vitamin D3 at each meal for juveniles, and twice a week for adults. A specific multivitamin supplement for amphibians must be administered once a week.

Compatibility: Must be housed exclusively in species-only terrariums to avoid stress and food competition. It is possible to maintain a small group consisting of one male and two females, ensuring that space is sufficient and that there are multiple hiding spots. Males can be territorial, so it is not recommended to keep multiple males in the same space unless the terrarium is large.

Health and Common Diseases: The main cause of death in captivity is dehydration due to misting system failures. Fungal skin infections (such as chytridiomycosis) and bacterial infections are common in dirty or poorly ventilated environments. It is essential to ensure good air exchange without compromising humidity. Calcium deficiency can cause metabolic bone disease, visible from limb deformities or movement difficulties.