Description
Hyloscirtus princecharlesi has a robust body and limbs, with a snout-vent length of 68.1 - 70.5 mm. The snout is truncate viewed both from above and from the side. Its head is as wide as it is long. The lips of H. princecharlesi are rounded, but not flared. The nostrils point forward and to the side, and are only slightly protuberant. The top of the head and the internarial region are flat. The tongue is broad and fully attached to the floor of the mouth. There is a singular, subgular vocal sac. The tympanum is vertically ovoid, and a thick supratympanic fold runs from the eye to the shoulder. The forearms of H. princecharlesi are much thicker than the upper arms. The fingers are broad, with rounded (but only slightly expanded) discs. Relative finger length, in ascending order, is 1,2,4,3. Fingers are webbed basally. A glandular nuptial pad is present on finger 1. The hind limbs are robust. The discs on the toes are not expanded. Relative toe length, ascending, is 1,2,3,5,4. The feet have some basal webbing (Coloma et al. 2012).

H. princecharlesi can be distinguished from other members of the Hyloscirtus larinopygion group by its unique coloration (evenly spaced orange spots on a black background), grey iris color, poorly expanded discs on the digits, and its glandular nuptial pad (Coloma et al. 2012).

Coloration in life: The base color of the dorsum is black, and it is spotted with rounded orange patches, some of which may overlap, forming a reticulated pattern around mid dorsum. The markings on the limbs are larger than those on the body. The iris is gray. The ventral surfaces are black with a yellow-cream marbling. The palmar surfaces and undersides of the digits are gray (Coloma et al. 2012).

Coloration in 70% ethanol: The orange spots fade to a light orange brown coloration. The ventral surface has diffuse gray marbling on a black surface (Coloma et al. 2012).

Tadpole Morphology: A tadpole at stage 36 had a total length of 89.1 mm (28.4 mm body), with a height of 13.2 mm. The body is ovoid, and the snout is rounded. A lateral line system is evident. The nostrils are small and oval in shape, and point anterolaterally. The eyes are located dorsolaterally, and are about 3mm in width. An oral disc of width 10 mm is located on the ventral surface of the head, toward the front. The oral disc is completely bordered by two rows of papillae. The tail is robust and muscular (Coloma et al. 2012).

Tadpole Coloration: The dorsum is brown, with scattered cream flecks. The iris is turquoise in color, with a green lavender annulus with white flecks around the pupil. The lateral line system is seen as a line of cream-colored spots. The spiracle and mouth are a translucent cream color. The venter is a red brown color in the forward portion, while the back portion is dark brown; both have cream-colored dots. The tail is brown for much of its length, becoming a lighter cream color towards the tip. In preservation, the brown colors fade to a grayish brown.

Significant changes in color occur during metamorphosis in H. princecharlesi larvae. Around stages 40-42, the dorsum becomes gray and the hind limbs change from cream-colored to greenish gray. By stage 44, the body becomes a yellow-green color, with black mottling on the limbs. Early juveniles are yellow green with mottling on the flanks, and the iris and tips of the digits are gray (Coloma et al. 2012).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Ecuador

View distribution map in BerkeleyMapper.

H. princecharlesi is only known from the type locality, a stream in the montane cloud Forest, Provincia de Imbabura, Ecuador. This locality is at the border of Reserva Eologica Cotacachi-Cayapas, in the mountain range Cordillera de Toisan, part of the Andes. The species was found between 2720 and 2797 meters in elevation (Coloma et al. 2012).

It can be found in the dense shrubbery around the edges of streams (Coloma et al. 2012).

Life History, Abundance, Activity, and Special Behaviors
H. princecharlesi has been found active during the evenings and at night, in vegetation near streams (Coloma et al. 2012).

Trends and Threats
Its only known locality is at significant risk due to human modifications and destruction. Activities such as logging, burning unregulated agricultural use, cattle grazing, pesticides, and introduction of trout all are detrimental to the survival of this species. Threats which have been observed in other Andean frogs, such as climate change and pathogen spread, may also negatively impact H. princecharlesi (Coloma et al. 2012).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation
Local pesticides, fertilizers, and pollutants
Predators (natural or introduced)
Disease
Loss of genetic diversity from small population phenomena
Climate change, increased UVB or increased sensitivity to it, etc.

Comments

The species was named for His Royal Highness Charles, Prince of Wales, because of his contributions to conservation of tropical ecosystems. He has worked to raise awareness about deforestation, climate change, and the extinctions of rainforest amphibians, using frogs as symbols of his cause (Coloma et al. 2012).

H. princecharlesi is a part of the Hyloscirtus larinopygion group. Its sister species (closest relative) is H. ptychodactylus (Coloma et al. 2012).

References

Coloma L. A., Carvajal-Endara, S., Dueñas J. F., Paredes-Recalde, A., Morales-Mite, M., Almeida-Reinoso D., Tapia E. E., Hutter, C. R., Toral, E., and Guayasamin, J. M. (2012). ''Molecular phylogenetics of stream treefrogs of the Hyloscirtus larinopygion group (Anura: Hylidae), and description of two new species from Ecuador.'' Zootaxa, 3364, 1-78.

Species Account Citation: AmphibiaWeb 2012 Hyloscirtus princecharlesi: Prince Charles Stream Tree Frog <https://amphibiaweb.org/species/7845> University of California, Berkeley, CA, USA. Accessed Nov 23, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Nov 2024.

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