Hemiphractus johnsoni is the most generalized species in the subfamily Hemiphractinae. This suggests that it may resemble the ancestral hemiphractine that presumably evolved from a neotropical relative in the family Hylidae ("true" treefrog group) (Trueb 1974). Though interesting in appearance and their reproductive behavior, the Hemiphractinae have not been as thoroughly researched as some other tropical anurans.
The population status of this species is unknown, but it is undoubtedly threatened by the destruction of primary rainforest.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: endangered
Development - Life Cycle: metamorphosis
Little is known of the feeding habitats of H. johnsoni, but insects and other small invertebrates probably constitute most of the diet, as in other hylid frogs. Lizards are not normally part of a small frog's diet, but a lizard was once found in the stomach of a related hemiphractine specie (Trueb 1974).
Hemiphractus johnsoni is thinly distributed over a vast range. It occupies elevations of 300m to 1910m in the Northern Andean slopes of Colombia, the upper Amazon Basin, and lower Amazonian slopes of the Andes from Ecuador to Northern Bolivia (Trueb 1974).
Biogeographic Regions: neotropical (Native )
Hemiphractus johnsoni inhabits dense, lowland tropical rainforests (Trueb 1974).
Terrestrial Biomes: rainforest
Aquatic Biomes: coastal
Hemiphractus johnsoni is sexually dimorphic; females are significantly larger than males. Snout to vent length in males averages approximately 52.9mm, while females average 77.2mm in length. There are scattered tubercles on the dorsal surface and forearms, and poorly developed tubercles on the hind limbs, of all hemiphractine species. The granular eyelids also have one or two enlarged conical tubercles. On the tip of the snout of H. johnsoni is a small, triangular and dorsoventrally flattened, fleshy proboscis. The shape of this proboscis is one of the ways H. johnsoni differs from the other hemiphractine species. A unique feature in H. johnsoni is the presence of a small, round post- orbital depression with a light crossbar; conversely H. johnsoni lack the provomerine teeth that other hemiphractine species possess. The color pattern of the dorsum is tan-brown with reddish mottling and darker spots. The forelimbs and hind limbs are a pale ground color with dark transverse. The outer digit of the unwebbed hands are noticebly darker than the inner digits. The back feet have basal webbing and the adhesive discs of the toes are slightly smaller than those of the fingers (Trueb 1974).
Other Physical Features: ectothermic ; bilateral symmetry
Genus Hemiphractus is unique in that the eggs undergo direct development in a brood pouch on the dorsum of the female (Duellman and Trueb 1986). In the month of July, an H. johnsoni was found with seventeen eggs in her dorsal pouch. Another specimen wes found with eighteen young attached to her back. However, the average number of young associated with adult females was only eleven (Trueb 1974).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate)
Hemiphractus johnsoni, or the Johnson's horned treefrog, is a species of frog in the family Hemiphractidae. It is endemic to Colombia and known from the Cordillera Central in Antioquia and Caldas Departments as well as from the Cordillera Oriental in Huila Department. Prior to 2001, what now is known as Hemiphractus helioi was included in this species.[2][3] Its natural habitat is primary cloud forest. It is threatened by habitat loss.[1]
Hemiphractus johnsoni, or the Johnson's horned treefrog, is a species of frog in the family Hemiphractidae. It is endemic to Colombia and known from the Cordillera Central in Antioquia and Caldas Departments as well as from the Cordillera Oriental in Huila Department. Prior to 2001, what now is known as Hemiphractus helioi was included in this species. Its natural habitat is primary cloud forest. It is threatened by habitat loss.
