Description

Adult Morphology:

The forelimbs are not hypertrophied (Rivera-Correa et al. 2016) but the forearms are robust, with no axillary membrane and low ulnar tubercles. The fingers are thick and short, each having a large ovoid disc. Relative finger length order is 1 < 2 < 4 < 3. The fingers have wide dermal fringes and are webbed basally. There are many tubercles present, which include a large rounded subarticular distal tubercles on the fingers, a large supernumerary tubercle at the base of the palm, an outer metacarpal tubercle, and a large, thick inner metacarpal tubercle. There is also a broad elliptical prepollex present. In males, the nuptial pad is large, covering the medial part of the prepollex and the distal region covering the dorsal surface of finger 2. The nuptial pad also contains epidermal projections (Rivera-Correa and Faivovich 2013).

The hindlimbs are also strong with the tibia length being 53% of the snout-vent length and the foot length being 46%. Like the forelimbs, the hindlimbs also have many tubercles, which include a small pyramidal calculator tubercle, an outer metatarsal tubercle, a large inner metatarsal tubercle, small tubercles running along the tarsus, large round subarticular tubercles, and single rows of small supernumerary tubercles on each toe that run along the axis. There is no tarsal fold. Also like the forelimbs, the toes are short, containing lateral fringes and disc on each toe. Relative toe length is 1 < 2 < 3 = 5 < 4 (Rivera-Correa and Faivovich 2013).

The cloacal opening is directed posteroventrally, around the midlevel of the thighs. At the margins of the vent, there are many small folds, but no supracloacal flap, the cloacal sheath is also relatively short. Two large, swollen glandular areas reside proximally to the posterior thighs (Rivera-Correa and Faivovich 2013).

Tadpole/larvae Morphology:

Tadpoles of H. antioquia are characterized by features commonly found in tadpoles that inhabit lotic environments, including a depressed body, low fins, an oral disc containing several labial tooth rows, and a long, well-developed tail with complex musculature. At stage 37, the larval shape can generally be described as egg-like and depressed. The body width measures 16 mm on average, while body length measures 26.9 mm on average. Body height is generally around 12.2 mm on average. Overall, their total length at this stage tends to be around 81.8 mm. The snout of H. antioquia larvae is rounded in dorsal view, and from the side, gradually slopes at its nares. The nostril to snout distance of these larvae measures around 5.6 mm on average. The anterolaterally-directed nostrils on the snout are elliptic in shape and incredibly small, on average, the nostril width is a mere 0.7 mm. Inter-nostril distance is generally 5.5 mm. A prominent fleshy projection is found right between the eyes and the snout. The eye to snout distance in total averages 8.6 mm total. The eye diameter averages 2.5 mm, are located at the end of the anterior third of the head, and are directed dorsolaterally. The average inter-orbital distance of the eyes is around 7.7 mm. The upper jaw sheath narrows to form a keratinized arch that is about 48% of the transverse width of the oral disc. Less protuberant is the lower jaw sheath, which is thin and forms a V-shape. While the upper and lower jaw sheaths are quite different, they both have finely serrated edges. In terms of respiratory openings, these tadpoles have sinistral spiracles at the mid-body level that have an opening at the middle third of its body. This spiracular opening is quite small, measuring about 3.9 mm in length on average. It is also round and has a posterodorsal orientation. The total tube length usually measures around 3.0 mm. The vent tube is located along the ventral middline and is attached ventrally to the tail, with an opening that is dextrally directed. The aperture of the vent tube is large and opens from a saccular structure that encloses it. Its overall length is generally 6.0 mm. Their tail is quite long, typically around 49.3 mm. The total height of the tail is 14.2 mm on average, but tail musculature height is around 8.2 mm. The dorsal fin originates at the same level of the tail with its height almost that of the tail itself. The maximum height the dorsal fin reaches is at mid-length of the tail and it rises above the body. As for the ventral fin, it originates at the base of the tail musculature and is nearly the same height as the tail but reaches a maximum at the mid-length of the tail (Rivera-Correa and Faivovich 2020).

DIAGNOSIS:

As of 2021, the genus Hyloscirtus contains 39 species of stream-dwelling treefrogs. Its species is divided into three species groups, including H. armatus, H. bogotensis, and H. larinopygion. The main way of differentiating H. antiouquia from other frogs of the same genus is its distinct coloration. Compared to other frogs, like its sister species H. larinopygion, H. antioquia is darker and has contrasting bright patterning that stands out. Other frogs in its genus have a much darker dorsal patterning or even lack a dorsal patterning. The grey iris with burgundy reticulation is also different from other members of the genus. The toes are also different from other species in which they are grayish black dorsally and blueish-gray ventrally. The fingers have larger nuptial pads with epidermal projections that are usually darker brown than other members of the genus. A broad elliptical prepollex that is not modified to be a projecting spine differentiates H. antioquia from Hyloscirtus tapichalaca (Rivera-Correa and Faivovich 2013).

COLORATION:

In life, the dorsum of H. antioquia is reddish-brown with an orange blotch-like patterning that runs through the body, and turns yellow as it reaches the black flanks. The thighs of the frog are similar to the flanks, with a black background and yellow stripes that are outlined with blueish-gray. The nuptial pads are dark brown in color. The toes and fingers are gray and have black horizontal bars, which look like stripes, that run along the dorsal surface. Similarly, the discs are gray coloration on the dorsal side, while the ventral side of the discs are a blueish-gray. The gular region of the frog is brown, but the rest of the ventral areas are a dirty grey like the coloration of the toes and discs. The pericloacal region is grayish-brown. The eyes are grey and have burgundy reticulation (Rivera-Correa and Faivovich 2013).

In preserved specimens, the coloration is much darker and faded than live individuals. While the dorsum of the frog is still brown, the patterning is now gray instead of orange. The flanks of the frog are still black, but the yellowish patterning in that region become gray. Likewise to the flanks, the thighs of the frog retain the black coloration and the yellow patterning also becomes gray. The coloration for the toes and discs are all the same, as they retain the grey and black stripes on the toes and the grey on the discs. The ventral side of the preserved frog is much different as it is now a single color, gray (Rivera-Correa and Faivovich 2013).

VARIATION:

There is variation in size, color, shape of lateral markings, and between sexes. For color, the hue for individuals can range from almost orange to brown. Lateral marking color may also differ between individuals; some may have the dorsally scattered orange blotches and some may not. Additionally, individuals may have orange vertical bar markings on their thighs or dark-gray/ black markings on their abdomen. The number of vomerine teeth also differ between individuals, with a range of 14 - 18 or 12 - 20 teeth. Some individuals may also have more developed calcar tubercles, possibly a result of where they are living. Females have slimmer forearms than males (Rivera-Correa and Faivovich 2013).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia

View distribution map in BerkeleyMapper.

Hyloscirtus antioquia is found primarily in the northern sections of the Cordillera Central of Columbia (Rivera-Correa et al. 2017). Its habitat is the cloud forest of the high mountains where they live in or alongside streams and puddles or wetlands in the inland of Columbia. Some individuals have also been found to be perched < 3 meters high. Their elevation range consists of the upper limit at 3,200 meters and the lower limit at 2,500 meters (Rivera-Correa and Faivovich 2013).

Life History, Abundance, Activity, and Special Behaviors

Males call from shrubs and areas of low vegetation alongside streams of gallery forests after dusk and until early morning. The call of H. antioquia is characterized by a low-pitched, multi-pulsed note, with overlaps in frequency and pulse duration, and that resembles that of a cricket. Specifically, the dominant frequency measures between 1642.7 and 1756.5 hertz and has 5 to 6 periodic pulses. These calls were emitted at a rate of 23 to 25 calls per minute. (Rivera-Correa et al. 2017).

Hyloscirtus antioquia exhibit indirect development. Tadpoles typically inhabit lotic, or stream, environments (Rivera-Correa and Faivovich 2020).

Trends and Threats

One of the main threats to H. antioquia is disease. Specifically, Batrachochytrium dendrobatidis, a fungal pathogen, has been found in the Hyloscirtus larinopygion group in Columbia. Hyloscirtus antioquia is a species within the H. larinopygion group. In a study, H. larinopygion was the species to show the highest prevalence, as well as, the highest intensity of infection (Urbina et al. 2011).

Other threats include the increase of urbanization their range and invasive species. However, H. antioquia is found in many protected areas, which include San Sebastian la Castellana, Reserva Forestal Protectora, Nacional Río Nare Distrito de Manejo Integrado Divisoria Valle De Aburra-Río Cauca, and Distrito de Manejo Integrado Sistema de Páramos y Bosques Altoandinos (IUCN 2018).

Possible reasons for amphibian decline

General habitat alteration and loss
Urbanization
Disease

Comments

PHYLOGENETIC RELATIONSHIPS:

Within the genus, Hyloscirtus, there are three groups, H. bogotensis, H. armatus, and H. larinopygion. Hyloscirtus antioquia is a member of the latter, split from and sister to H. larinopygion (Rivera-Correa et al. 2017).

ETYMOLOGY (Origin or explanation of scientific name):

The species epithet, "antioquia” is in reference to the Grupo Herpetologico de Antioquia, one of the diverse areas of amphibians in the neotropics, and also alludes to the distribution of where this species originated from, the Departmento de Antioquia in Colombia. It is unclear where the name "Antioquia" originated from and what it means, however, several historians suggest that it could be an Amerindian term that means “mountain of gold” (Rivera-Correa and Faivovich 2013).

References

IUCN SSC Amphibian Specialist Group. (2018). "Hyloscirtus antioquia (amended version of 2017 assessment)." The IUCN Red List of Threatened Species 2018: e.T78964958A136510568. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T78964958A136510568.en. Downloaded on 18 February 2021.

Rivera-Correa, M., Faivovich, J. (2013). "A new species of Hyloscirtus (Anura: Hylidae) from Colombia, with a rediagnosis of Hyloscirtus larinopygion (Duellman, 1973)." Herpetologica, 69(3), 298–313. [link]

Rivera-Correa, M., Faivovich, J. (2020). ­"The tadpole of the stream treefrog Hyloscirtus antioquia (Anura: Hylidae: Cophomantini)." Studies on Neotropical Fauna and Environment, 1–7 [link]

Rivera-Correa, M., Vargas-Salinas, F., Grant, T. (2017). "Statistical differences and biological implications: a comparative analysis of the advertisement calls of two Andean stream treefrogs (Hylidae: Hyloscirtus) and the evolution of acoustic characters." Salamandra, 53(2), 237–244. [link]

Urbina, J.C., Galeano, S.P. (2011). "Batrachochytrium dendrobatidis detected in amphibians of the central Andean Cordillera of Colombia." Herpetological Review 42(4): 558-560 [link]

Species Account Citation: AmphibiaWeb 2021 Hyloscirtus antioquia <https://amphibiaweb.org/species/8062> University of California, Berkeley, CA, USA. Accessed Oct 28, 2021.

Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 28 Oct 2021.

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