Description
Amolops mahabharatensis is a high altitude torrent frog described from four males and two females. The body of A. mahabharatensis is of moderate size with the snout vent length in males ranging from 33.91 - 39.11 mm and the snout vent length in two females being 65.0 and 71.79 mm. The head is flat, and wider than it is long. The snout is short and round in lateral view. The canthus rostralis is distinct, and the nostrils are lateral. The loreal region is slightly concave. The eyes of A. mahabharatensis are small and convex, and the eye diameter is shorter than the snout length. The inter-orbital distance is greater than the width of the upper eyelid and the internarial distance. The tympanum is small in size. The supratympanic fold is present and extends from the back of the eye to the shoulder. There are small tubercles present between the junction of the supratympanic fold and the upper mandible. Gular pouches are present (Khatiwada et al. 2020).

The forearms of A. mahabharatensis are shorter than the hand. The outer metacarpal tubercle is ovoid, flat, and larger than the inner tubercle, which is round and small. The relative finger lengths are I < II < IV < III, and the third and longest finger is shorter than the arm. The fingertips have oval disks with circummarginal grooves. The width of the third disk is greater than the tympanum. In males, there is a nuptial pad on the first finger, which does not have conical spines. The fingers do not have distinct lateral fringes, nor do they have webbing. There are rounded subarticular tubercles present, and the formula for these tubercles is 1, 1, 2, 1 (Khatiwada et al. 2020).

The hind limbs are robust and long, and the tibiotarsal articulation reaches the snout when the hind limb is adpressed along the body. The shank is longer than the thigh, tarsus, and foot. The inner metatarsal tubercle is prominent and oval, while the outer metatarsal tubercle is poorly developed. Supernumerary and plantar tubercles are not present. The toes are thin and long, and their relative lengths are I < II < III < V < IV. The tips of the toes have circular disks with circummarginal grooves. The toes are fully webbed, and the subarticular tubercles are slightly ovoid, with formula 1, 1, 2, 3, 2 (Khatiwada et al. 2020).

The skin is granular on the dorsal head, body, limbs, fingers, toes, and flank regions. The intensity of the granular warts increases when approaching the vent. The flanks have large granules. The dorsolateral fold is very weakly developed, and has warty granules. The abdomen and ventral surfaces of the head, body, and thighs are free of granules. The tympanum is smooth (Khatiwada et al. 2020).

Amolops mahabharatensis is assigned to the Amolops genus based on molecular and morphological similarities. Specifically, A. mahabharatensis has a first finger with circummarginal and transverse grooves on its disk. Also, like the other members of the Amolops genus, the tadpoles of A. mahabharatensis are gastromyzophorous, and have a ventral sucker. Amolops mahabharatensis was found to be a member of the A. marmoratus species group, a subgroup of the Amolops genus, which consists of A. afganus, A. indoburmensis, A. marmoratus, A. nepalicus, A. panhai, and now, A. mahabharatensis (Khatiwada et al. 2020).

Amolops mahabharatensis differs from A. afganus by its granular dorsal surface, whereas A. afganus has less granular skin. The body of A. mahabharatensis is also smaller in both males and females, as the snout-vent length in males of A. mahabharatensis ranges from 33.9 - 39.1 mm, whereas the snout-vent length of A. afganus ranges from 45.6 - 62.9 mm. In females, the snout-vent length of A. mahabharatensis ranges from 61.0 - 71.7 mm, while the snout-vent length of A. afganus ranges from 67.6 - 94.1 mm. Amolops mahabharatensis also has a relatively larger tympanum than A. afganus (Khatiwada et al. 2020).

Amolops mahabharatensis differs from A. indoburmanensis by its fine granulation, whereas A. indoburmanensis has coarse granulation in its body and limbs. Amolops mahabharatensis also has a smaller body in both males and females, as the snout-vent length of males of A. indoburmanensis ranges from 59.0 - 86.0 mm, and the snout-vent length of females of A. indoburmanensis ranges from 63.0 - 106.0 mm. Also, the head of A. mahabharatensis is wider than it is long, whereas the head of A. indoburmanensis is longer than it is wide (Khatiwada et al. 2020).

The head of A. marmoratus is longer than it is wide, unlike that of A. mahabharatensis. While A. mahabharatensis has a distinct tympanum, the tympanum of A. marmoratus is indistinct. Lastly, the supernumerary tubercles on the fingers of A. mahabharatensis are absent, while three of the outer fingers of A. marmoratus have supernumerary tubercles. Amolops mahabharatensis also differs from A. nepalicus by having a head wider than it is long, whereas the head of A. nepalicus is longer than it is wide. The head of A. panhai is also longer than it is wide, unlike that of A. mahabharatensis, and gular pouches are present in A. mahabharatensis males, while they are absent in males of A. panhai. Amolops mahabharatensis also has a larger body in females, as the snout-vent length of females of A. indoburmanensis ranges from 47.2 - 57.5 mm (Khatiwada et al. 2020).

In life, the dorsum of adults is greyish-olive, and the dorsolateral and supratympanic folds are light brown. The iris is pale yellow to light gold, and the pupil is black. The thighs have black bands, and the flanks have large white granules. The toe webbing is brown, and the ventral region is white (Khatiwada et al. 2020).

In preservative, the dorsum of the head and the body are dark brown. The dorsal region of the thigh is brown, and the flanks are creamy. The lateral surfaces of the arms and thighs have a light rust coloration. The dorsal granules turn from creamy white to black. There are transverse cross-bars on the dorsal surfaces of the hands, shanks, tarsus, and feet, which are grey. The flanks and ventral surfaces of the hands and thigh regions are creamy white, as are the ventral surfaces of the head and abdomen. The webbing of the toes is semi-transparent and grey (Khatiwada et al. 2020).

There appears to be sexual dimorphism among A. mahabharatensis. Overall, females are significantly larger, with a snout-vent length ranging from 65.0 - 71.79 mm, while the snout-vent length of males ranged from 33.91 - 39.11 mm. Males also have secondary sexual characters in the form of a sub-gulag vocal sac and distinct nuptial pads. Finally, males have thick, robust forearms, while the forearms of females are thin and long (Khatiwada et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Nepal

View distribution map in BerkeleyMapper.

Amolops mahabharatensis is found in the Mahabharat range of Nepal and inhabits torrent streams, which have high canopy cover, usually located in subtropical mixed forests (Khatiwada et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
Adults of A. mahabharatensis were collected from rocky boulders in a fast-flowing stream. Tadpoles of A. mahabharatensis are gastromyzophorous, and were found attached to rocks below water (Khatiwada et al. 2020).

Larva

Larvae of A. mahabharatensis were examined in Gosner stage 32. In dorsal view, the larval body is oval or elliptical, and the posterior region is wider than the anterior region. The total length averages 34.8 mm; the body length averages 16.7 mm and makes up approximately 48% of the total length. The tail length averages 22.1 mm and makes up approximately 61% of the total length. The head is broad, and the snout is rounded. The eyes are positioned dorsolaterally, and the naris is oval and quite close to the snout. The oral disc lacks papillae, and there are three uninterrupted labial tooth rows and five interrupted labial tooth rows on the upper labium. On the lower labium, there are two uninterrupted labial tooth rows and one interrupted tooth row. The keratodont formula is III:5+5/1+1:II. Both the upper and lower beak are V-shaped, and the margins are serrated with about 64 serrates in the upper beak and 36 in the lower beak. In the ventral view, a large sectorial abdominal disk is present and covers approximately 80% of the ventral body area. The single spiracle is sinistral, midventral, posterodorsally directed, and extended as a short tube. The spiracular opening is oval. The dextral vent tube opens at the margin of the ventral fin. The tail musculature is robust, and it narrows greatly towards the rounded tail tip. The dorsal fin originates behind the body, at the first quarter of the tail-body junction, while the lower tail fin originates near the middle of the tail. The upper tail fin is taller than the lower fin. Both fins merge at the tip (Khatiwada et al. 2020).

In preservative, tadpoles have a dark brown coloration on the dorsal and lateral surface of their head, body, and tail regions. The beak is completely black. Their abdominal disc is creamy white, the abdomen is light grey, and the ventral surface of the tail is also creamy white (Khatiwada et al. 2020).

Trends and Threats
Many frog species, including A. mahabharatensis, in the Mahabharat range of Nepal, as well as in other mountainous regions of Asia, are used as resources for survival. Due to the dependence of mountainous villages on natural resources, there is severe overharvesting of A. mahabharatensis adults and even eggs. This population of A. mahabharatensis is highly threatened and at risk of extinction by recent global environmental changes, and is accelerated by anthropogenic activities like overharvesting (Khatiwada et al. 2020). Khatiwada et al. (2020) recommend the prioritization of population monitoring and conservation efforts in the studied area, and also in other regions of Nepal.

Relation to Humans
Ethnoherpetology is a very common practice in the communities of mountainous regions of Nepal, where A. mahabharatensis inhabits. As a result, many people interact with and collect A. mahabharatensis individuals for study and use (Khatiwada et al. 2020).

Possible reasons for amphibian decline

Intentional mortality (over-harvesting, pet trade or collecting)
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
Phylogenetic analysis was done on the 16S mitochondrial gene using both Bayesian inference and Maximum likelihood methods, resulting in identical topographies. From the analysis, Amolops mahabharatensis was found to be sister to a clade formed by A. nepalicus and A. panhai. The clade formed by these three species is sister to a clade formed by A. marmoratus, A. indoburmanensis, and A. afganus. The clade formed by the aforementioned six species is sister to a clade formed by A. nyingchiensis, A. bellulus, A. cucae, A. mengyangensis, A. liangshanensis, A. loloensis, A. jinjiangensis, A. tuberodepressus, A. viridimaculatus, A. medogensis, A. lifanensis, A. mantzorum, A. xinduqiao, A. chayuensis, A. formosus, and A. chunganensis. The clade formed by these 22 species is then sister to a clade formed by A. ricketti, A. yatseni, A. sinensis, A. albispinus, A. yunkaiensis, A. wuyiensis, A. hongkongensis, A. daiyunensis, A. hainanensis, A. torrentis, and A. spinapectoralis. The clade formed by all 33 of these species is sister to a clade formed by A. australis and A. gerutu, and finally, the clade formed by these 35 species is sister to A. cremnobatus (Khatiwada et al. 2020).

Amolops mahabharatensis is named after the Mahabharat range of Nepal, where A. mahabharatensis is found (Khatiwada et al. 2020).

Based on morphology, A. mahabharatensis was initially categorized as A. marmoratus, another species that inhabits the Mahabharat range of Nepal. However, after many molecular analyses, several cryptic amphibians have been identified as new species that were originally assigned to A. marmoratus, with A. mahabharatensis being one of them. The discovery of this species prompts further research into the cryptic diversity of the Amolops genus in Nepal (Khatiwada et al. 2020).

References

Khatiwada, J. K., Wang, B., Shu, G., Zhao, T. (2020). ''Description of a New Species of Amolops Cope, 1865 (Amphibia Ranidae) from Nepal and Nomenclatural Validation of Amolops nepalicus Yang 1991.'' Asian Herpetological Research, 11, 71-95.

Species Account Citation: AmphibiaWeb 2022 Amolops mahabharatensis: Mahabharat Torrent Frog <https://amphibiaweb.org/species/9217> University of California, Berkeley, CA, USA. Accessed Dec 3, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 3 Dec 2024.

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