Description

DESCRIPTION:

Guibemantis tasifotsy is a tree frog from Madagascar with a male snout-vent length range of 22.5 - 26.7 mm and a female snout-vent length range of 20.5 - 24.9 mm. The head is slightly wider than it is long and is wider than the body. The snout appears pointed when viewed from the dorsal, ventral and lateral views. The nostrils are located more closely to the tip of the snout than to the eyes, and are pointed forward. The canthus rostralis appears rounded. The tympanum is clearly visible and is smaller than the eye. The forelimbs are thin, with the forearm being shorter in length than the hand. The hands have enlarged and circular finger discs with no webbing between the fingers. The hind limbs are long and slender and the tibia is slightly longer than the femur. The feet are nearly the same length as the tibia, and there is moderate webbing between the toes and enlarged, rounded toe discs (Lehtinen et al. 2012).

DIAGNOSIS:

Guibemantis tasifotsy can be differentiated from other species within its subgenus (Pandanusicola), which have similar external morphology (species include G. albonlineatus, G. annulatus, G. bicalcaratus, G. flavobrunneus, G. punctatus, and G. wattersoni), based on its coloration. Guibemantis tasifotsy is mainly green on the dorsum with distinct white blotches on the lower flanks, versus the mainly brown dorsum lacking blotches of previously mentioned species. Guibemantis tasifotsy appears most similar to two species within its genus: G. pulcher and G. liber. Guibemantis tasifotsy and G. pulcher are similar in coloration, however, G. pulcher lacks the white lateral blotches. Guibemantis tasifotsy also has different femoral gland structure--larger glands with many smaller granules spread over the entire ventral side of the thigh--and breeding biology from G. pulcher. Guibemantis tasifotsy and G. liber have many similarities like femoral gland structure, breeding biology and coloration, however, G. liber lacks the copper metallic coloration around the eyes, nose and front of snout that is present in G. tasifotsy. These two species also have very different advertisement calls (Lehtinen et al. 2012).

COLORATION:

In life, this species has a vivid light green primary body color with a deep chocolate brown supratymanic fold, rostral stripe, and dorsal spots. There is also some metallic copper coloration found around the rostral stripe, eyes, and snout. Paired, thin white lines are present on the dorsum. The ventral surface is white toward the anterior region (throat, chest, and anterior belly), and towards the posterior region it is light green and slightly transparent. The femoral glands are a yellowish color and the iris is a light golden in color (Lehtinen et al. 2012).

In preservative, this species is medium brown with two obvious but irregular light dorsolateral lines. The metallic copper coloration that appears in life fades to a reddish coloration in preservative. The back of the dorsum is a mixture of light and dark irregularly shaped spots. The dorsal surface of the thigh has small, dark blotches. Some of the finger and toe discs have a reddish-brown coloration that is clearly different from the surrounding tissue color. White spots are present on both sides of the body and the ventral surface is a solid cream-color. The iris appears white or gray in preservative (Lehtinen et al. 2012).

VARIATION:

Variation amongst individuals can be seen in coloration of multiple features and in external morphology. The white lateral spots are found on most specimens, but individuals have been found that lack these spots entirely or that have additional spots on the belly. The number, size, and shape of these spots varied as well. The metallic copper coloration is always found on the snout and rostral stripe, but there is variation in how far it extends onto the skin surrounding the eyes. The coloration of the supratympanic fold can either be prominent and dark or less prominent. There is also variation in the coloration of the finger and toe discs as some have discs that appear different in color from the adjacent skin, while others have discs that do not appear differently colored. The degree of webbing on the foot can vary for some toes. The femoral glands of males always have obviously visible granules, but some individuals can have more pitted granules or granules with white dots inside (Lehtinen et al. 2012). This genus also exhibits sexual dimorphism where females are larger than males (Glaw et al. 2007).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Madagascar

View distribution map in BerkeleyMapper.

This species is endemic to Madagascar. In particular, individuals have been found in the southeastern region of the country. As of 2012, three populations have been observed in the following National Parks: Ranomafana National Park, Vevembe Forest, and Andringitra National Park. This region falls between 21° to 23° latitude and 46° to 48° longitude. All recorded sightings exist at low elevations from 580 - 810 m asl within the parks, however complete elevation range was not known as of 2021. More specifically, in the Ranomafana National Park, individuals were located at 605 m above sea level near the city of Mangevo (particular sites include: Maharira, Samalaotra, and Vohiparara). In the Vevembe Forest, individuals were found near the city of Vondrozo at 581 m above sea level. In the Andringitra National Park, individuals were found near the Sahavatoy River at 810 m above sea level (Lehtinen et al. 2012).

Individuals found in the Vevembe Forest were in foliage between 0.5 and 1.0 m in flooded forest habitat. Populations found in Ranomafana were found on foliage at 2.0 m in large open swamp habitat. Generally, individuals are found in reeds and vegetation cover above large, open lowland swamps or flooded forests. Plants from the genus Pandanus are the most common to have been inhabited by this species (Lehtinen et al. 2012).

Life History, Abundance, Activity, and Special Behaviors
Frogs from the genus Guibemantis, are known to lay eggs in slow-flowing water or small water-filled cavities of terrestrial plants (phytotelms) (Glaw et al. 2007). Due to the habitat characteristics of the Mangevo, individuals are assumed to utilize swamp waters for egg deposition and to complete indirect development (Lehtinen et al. 2012).

Vocalization behavior in G. tasifotsy consists of a unique style of calls. Individuals have been recorded vocalizing on plant foliage at heights of up to 2 m. Mangevo populations begin vocalizations at dusk and at temperatures between 18 to 20 degrees. The calls are irregular and features 3 - 7 singular notes with varying intervals between them (Lehtinen et al. 2012).

Trends and Threats
The species population is believed to be decreasing based on ongoing declines in the range and quality of habitat. It has an IUCN Red List status of “Vulnerable” due its limited extent of occurrence and the ongoing declines in habitat in eastern Madagascar. The forest habitat of G. tasifotsy is receding due to agriculture, timber extraction, charcoal manufacturing, the invasive spreading of eucalyptus, livestock grazing, and expanding human settlements. Guibemantis tasifotsy is restricted in occurrence to mid-elevations and primary forests (of which there is little of at mid-elevations), which makes the removal of forests especially dangerous to this species because it is not tolerant of habitat degradation. This species is found in two protected areas, Ranomafana National Park and Andringitra National Park (IUCN 2020).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation

Comments
Based on Bayesian analysis of Cytb mtDNA G. tasifotsy is in a monophyletic clade with G. aff bicalcaratus and further broken up into two subspecies based on their ranges: Vevembe and Ranomafana (Lehtinen et al. 2012).

Guibemantis tasifotsy and other species belonging to the Mantellidae family, share a recent common ancestor that colonized the country of Madagascar between 76 to 87 million years ago (Crottini et al. 2012).

ETYMOLOGY (Origin or explanation of scientific name):

The species epithet is composed of two Malagasy words: “tasy” meaning “spot” and “fotsy” meaning “white”. It refers to the white spots on the flanks of these frogs (Lehtinen et al. 2012).

OTHER INTERESTING INFORMATION:

Guibemantis tasifotsy are predicted to be fluorescent based on high levels of biliverdin and their translucent skin (Tadoda et al. 2017). This means that the light they absorb is partially re-emitted and the frogs appear to glow in the dark.

References

Crottini, A., Madsen, O., Poux, C., Strauß, A., Vieites, D.R., Vences, M. (2012). "Vertebrate time-tree elucidates the biogeographic pattern of a major biotic change around the K–T boundary in Madagascar." PNAS 109(14): 5358–5363. [link]

Glaw, F., and Vences, M. (2007). Field Guide to the Amphibians and Reptiles of Madagascar. Third Edition. Vences and Glaw Verlag, Köln.

IUCN SSC Amphibian Specialist Group. (2020). “Guibemantis tasifotsy (amended version of 2016 assessment).” The IUCN Red List of Threatened Species 2020: e.T66390706A176400787. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T66390706A176400787.en. Downloaded on 17 February 2021.

Lehtinen, R.M., Glaw, F., Andreone, F., Pabijan, M., Vence, M. (2012). “A new species of putatively pond breeding frog of the genus Guibemantis from southeastern Madagascar”. Copeia 2012(4): 648-662. [link]

Taboda, C., Brunetti, A.E., Alexandre, C., Lagorio, M.G., Faivovich, J. (2017). “Fluorescent frogs: a herpetological perspective.” South American Journal of Herpetology, 12(1):1-13. [link]

Species Account Citation: AmphibiaWeb 2021 Guibemantis tasifotsy: White-flanked Malagasy Tree Frog <https://amphibiaweb.org/species/7954> University of California, Berkeley, CA, USA. Accessed Jan 5, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 5 Jan 2025.

AmphibiaWeb's policy on data use.