Description
Raorchestes ghatei is a shrub frog with a robust body and a reported snout-vent length in males of 19.1 - 25.5 mm and in females of 15.4 - 29.8 mm. The average snout-vent length of males is 21.7 mm and 21.4 mm for females (Padhye et al. 2013, Sayyed and Padhye 2020). The head length of this species is shorter than the width of the head. When viewed from a dorsal angle, the snout of this species tapers to a short point. The diameter of the eye is longer than the snout length in males, while in females the diameter of the eye is shorter than the snout length. It has a tympanum that is rounded and not very well defined. In both male and females, the hand length is longer than the length of the humerus, which is longer than the length of the forelimbs. There is no webbing on the fingers and the relative finger lengths are 3 > 2 > 4 > 1. The hindlimbs are long and the length of the thigh is longer than the length of the shank in both sexes. The toes have reduced webbing with a webbing formula of 2 – 2 II 2 – 2 ½ III 2 – 3 IV 2 ½ - 2 V and the relative toe lengths are 4 > 3 > 5 > 2 > 1. The skin on the snout is granular while the interorbital space is smooth. The dorsum has minute horny spinules or tubercles that are sparsely scattered. The lateral region has coarsely granular skin and dorsolateral folds. The gular is smooth while the rest of the ventrum, including the thighs is coarsely granular (Padhye et al. 2013).

Raorchestes ghatei can be differentiated from other species in this family by a variety of characteristics. Defining traits include a small, rounded and ambiguous tympanum, a snout that tapers to a short point, and a tongue that is in lacking papilla yet possesses a lingual pit. More specifically, R. bombayensis has more conspicuous spinules or tubercles than R. ghatei (Padhye et al. 2013).

Coloration varies by sex. In life, females have a dark dorsum with an off-white mottled pattern and in the middle of the dorsum there are black stripes that run from the tympanum to the groin. The hindlimbs and forelimbs have black horizontal stripes. The trunk of R. ghatei females is a cream color that fades into a yellow-orangish at the end of the trunk. In preservation, the coloration of the females is fairly similar with the exception of the mottling, which does not persist through preservation (Padhye et al. 2013).

In life, males have a brown dorsum with a dark brown mottled pattern and in the middle of the dorsum there is a single black stripe that runs from the tympanum to the groin. The forelimbs are dark in color and possess no striping while the hindlimbs possess dark spotting. Similarly, to the female, the trunk is a cream color. In preservation, the coloration of the males appears similar, but is generally faded compared to a live individual (Padhye et al. 2013).

In addition to sexual dimorphism in coloration, males have smaller snout-vent lengths than females, and the humerus bone of the male contains a tubercle, while this feature is not present in females. Lastly, males possess a vocal sac underneath the gular sac while females lack this trait (Padhye et al. 2013).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: India

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

Raorchestes ghatei is found in the northern Western Ghats, State of Maharashtra, India. Specifically, their range starts in the north at Mulshi and Taleghar in the Pune District and extends south to Jaichiwadi. The species typically inhabits elevations around 600m and 1000m with fairly similar latitude and longitudes. Raorchestes ghatei is usually observed in semi-evergreen forests and scrub patches of Western Ghats (Padhye et al. 2013).

Life History, Abundance, Activity, and Special Behaviors
Raorchestes ghatei’s mating season is correlated to the region's rainy season and adults display peak activity from June through October. Calling usually begins around 6 pm, but can start earlier and may be triggered by light rain during the day. Calling often continues throughout the night. Males utilize their calls for both mating and territoriality. It has been observed that after a fight for territory, the dominant male in the area will be the only individual to use their call while the other males either emigrate or remain silent (Sayyed and Padhye 2020).

Males perch location is determined by timing within the mating season. At the beginning of the mating season, males will typically perch near the ground where female abundance is high. Near the end of the mating season, when females are less abundant, males can be found in tree perches as high as 3 - 5m off the ground. (Sayyed and Padhye 2020).

Females typically choose the loudest, most frequent calling male and the pair will mate using axillary amplexus. The fertilized eggs are then laid under a stone or dampened leaf litter. Following oviposition, males will resume calling and return to their previous perch site (Sayyed and Padhye 2020).

Females generally leave the clutch, but show a difference in behavior following the monsoon season. After the monsoon season, females have been observed to guard their clutch. This change in behavior is believed to be caused by an increased threat of moisture loss of their clutch. Females prevent this by wetting the eggs with water or urine. When females remain with their clutch, they also present highly defensive behavior, which is intended to combat predation. Sayyed and Padhye’s (2020) study indicated that clutches lacking a guarding female have increased rates of fungal infections and insect parasitism.

Raorchestes ghatei’s clutch size is around 40 - 60 eggs, which develop at an air temperature range of 20 - 22 degrees Celsius, although the soil temperature surrounding the clutch is 18.07 - 19.05 degrees Celsius. Average egg diameter varies from 2.49 - 2.53 mm and full development is completed after 21 - 30 days. During development, the egg membrane becomes more transparent and thin (Sayyed and Padhye 2020).

During larval development, eye position shifts from lateral to dorsal, and this change coincides with limb development. After the onset of hatching, juveniles emerge from their eggs after 24 - 48 hours. Adult activity noticeably decreases following the emergence of the hatchlings, and the abundance of calling males is observed to decrease as well (Sayyed and Padhye 2020).

Interspecific amplexus can occur within the Rhacophoridae family, and has been observed between R. ghatei and both Uperodon mormorata and Microhyla ornata. As this trait is most commonly observed in species displaying explosive breeding, Sayyed and Padhye (2020) report possible drivers of this behavior to be reproductive competition or a disproportionate number of available females.

Raorchestes ghatei prey varies upon life stage. Adult individuals generally prey upon both adult and juvenile crickets, small insects and spiders, as well as grasshoppers. Froglets will typically eat small insects and mosquitoes (Sayyed and Padhye 2020). Predators of R. ghatei include the Bamboo Pitviper, Changeable Lizard, Saw-scaled Viper, Forest Lizard, and White-throated Kingfisher (Sayyed and Padhye 2020).

Larva
Species of the genus Raorchestes displays direct development.

Trends and Threats
Deforestation in the Western Ghats could result in habitat fragmentation. Certain areas in which R. ghatei is found could become converted to wind farms. Wind farm conversion and habitat fragmentation could become additional threats to R. ghatei in the future (Padhye et al. 2013).

Although it is not currently a threat to the species, Batrachochytrium dendrobatidis (Bd), the chytrid fungus that causes chytridiomycosis, was found to have a 60% prevalence rate in R. ghatei. Out of the 19 amphibian species in a study, R. ghatei had the second highest prevalence rate after Fejervarya cf. caperata (75%). There were also elevated prevalence rates at locations closer to human settlements for unclear reasons (Thorpe et al. 2018).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities

Comments
Initial Maximum Likelihood analysis of the 16S rRNA gene showed that R. ghatei is most closely related to R. tuberohumerus and R. bombayensis (Padhye et al. 2013). However, further Maximum Likelihood analysis of the same gene indicate R. ghatei is sister to the clade composed of R. bombayensis, R. gryllus, R. longchuanensis, R. menglaensis, R. parvulus, R. shillongenus, and R. tuberohumerus (Al-Razi et al. 2020).

The species epithet, “ghatei”, is named after Dr. H.V. Ghate for his herpetological contributions to the Western Ghats of Maharashtra (Padhye et al. 2013).

References

Al-Razi, H., Marjan, M., Hasan, S., Muzaffar, S. (2020). "First record of Raorchestes longchuanensis Yang and Li, 1978 (Anura: Rhacophoridae) from northeastern Bangladesh suggests wide habitat tolerance." Amphibian and Reptile Conservation, 14(1), 119-131. [link]

Padhye, A. D., Sayyed, A., Jadhav, A., Dahanukar, N. (2013). "Raorchestes ghatei, a new species of shrub frog (Anura: Rhacophoridae) from the Western Ghats of Maharashtra, India." Journal of Threatened Taxa, 5(15), 4913-4931. [link]

Sayyed, A., Padhye, A. (2020). "Natural history of Ghate’s Shrub Frog, Raorchestes ghatei (Rhacophoridae), from the northern Western Ghats, India." , 26(3), 205-210. [link]

Thorpe CJ, Lewis TR, Fisher MC, Wierzbicki CJ, Kulkarni S, Pryce D, Davies L, Watve A, Knight ME. (2018). "Climate structuring of Batrachochytrium dendrobatidis infection in the threatened amphibians of the northern Western Ghats, India." R. Soc, Volume 5(6). [link]

Species Account Citation: AmphibiaWeb 2022 Raorchestes ghatei: Ghate's Shrub Frog <https://amphibiaweb.org/species/8099> University of California, Berkeley, CA, USA. Accessed Dec 23, 2024.

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

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