Journal of Threatened Taxa | www.threatenedtaxa.org | 26 March 2023 | 15(3): 22900–22904

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)

https://doi.org/10.11609/jott.8300.15.3.22900-22904

#8300 | Received 02 December 2022 | Final received 14 February 2023 | Finally accepted 20 February 2023

New distribution records of two uncommon microhylid frogs, Melanobatrachus indicus Beddome, 1878 and Mysticellus franki Garg & Biju, 2019 from Nelliyampathy, Kerala, India

Madhura Agashe ¹, Avrajjal Ghosh ², K. Dilshad ³, Maitreya Sil ⁴ & Aniruddha Datta-Roy ⁵

^1,2,4,5 School of Biological Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar, Odisha 752050, India.

³ Kerala Forest Research Institute, Peechi, Thrissur, Kerala 680653, India.

¹ madhura0398@gmail.com (corresponding author), ² avrajjal.ghosh@niser.ac.in, ³ kdilshad554@gmail.com, ⁴ maitreya.sil@niser.ac.in, ⁵ datta.roy@niser.ac.in

Editor: S.R. Ganesh, Chennai Snake Park, Chennai, India. Date of publication: 26 March 2023 (online & print)

Citation: Agashe, M., A. Ghosh, K. Dilshad, M. Sil & A. Datta-Roy (2023). New distribution records of two uncommon microhylid frogs, Melanobatrachus indicus Beddome, 1878 and Mysticellus franki Garg & Biju, 2019 from Nelliyampathy, Kerala, India. Journal of Threatened Taxa 15(3): 22900–22904. https://doi.org/10.11609/jott.8300.15.3.22900-22904

Copyright: © Agashe et al. 2023. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

Funding: (a) Internal funding from National Institute of Science Education and Research (NISER)

under the Department of Atomic Energy (DAE); (b) SERB CRG grant CRG_2021_000261.

Competing interests: The authors declare no competing interests.

Acknowledgements: The fieldwork was partly funded through a grant awarded to Dr. Aniruddha Datta-Roy by the Science and Engineering Research Board (SERB): File No. CRG/2021/00261. We thank the state forest department of Kerala for providing us necessary permits for field work (No. KFDHQ/4962/2020-CWW/WL10). We would like to acknowledge Bikash Sahoo for his assistance during fieldwork. We also thank the staff of the Nemmara Forest Division for their cooperation and assistance. Finally, we would like to thank the School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, Odisha, India, for the departmental and logistical support. K. Dilshad would also like to thank Dr. K.A. Sreejith, Principal scientist, Forest Ecology, Kerala Forest Research Institute.

Melanobatrachus indicus Beddome, 1878 or the Galaxy Frog was first described from the Anamalai Hills of Tamil Nadu (Beddome 1878). This southern Western Ghats endemic belonging to the monotypic genus Melanobatrachus is the sole representative of the subfamily Melanobatrachinae (Frost 2023). The IUCN has categorized this species as ‘Vulnerable’ (IUCN SSC Amphibian Specialist Group 2022), and it has been ranked as a high-priority EDGE species by the Zoological Society of London (Isaac et al. 2012). It is a rarely observed frog and has been reported from select locations in South India by only a handful of researchers since its discovery (Table 1, Figure 1). Another microhylid species Mysticellus franki Garg & Biju 2019, or the Mysterious Narrow-mouthed Frog was described from the Suganthagiri region (11.5386⁰N, 76.0538⁰E, 852 m) of the central Western Ghats in Wayanad district, Kerala. This genus is also monotypic; interestingly, its closest relative is the southeastern Asian genus Micryletta (Garg & Biju 2019). Since its discovery, this little-known frog has not been reported from any other location. In the current note, we report an additional distribution record for these elusive frogs from the southern Western Ghats.

While surveying for skinks and ants around Nelliyampathy Forest Reserve on 16 October 2022, at 1050 h, we encountered two adult individuals [34 mm and 32 mm snout-vent length (SVL)] of M. indicus (Image 1); sex undetermined). The individuals were found inside a patch of secondary evergreen forest around a reclaimed cardamom plantation (10.4730°N, 76.6738°E according to World Geodetic System WGS84; 970 m; Image 3). Both individuals were found under rotten logs along a forest pathway, approximately 10 meters from one another. Except for Nixon & Bhupathy (2007), prior records have found this species closely associated with water bodies (Rajkumar et al. 2021) whereas our location point was 150 m away from a perennial stream. The frogs showed typical external characters such as body slender; dorsal surface granular; ventral smooth; black body with numerous bluish-white spots and scarlet-orange blotches near the groin, belly, and between forelegs. When handled, the frogs appeared motionless with limbs tucked close to the body, indicating classical defensive behavior while under stress (Kanagavel & Tapley 2015).

On the same day, fieldwork in the vicinity of Kesavanpara (10.5236°N, 76.6708°E according to World Geodetic System WGS84; 950 m) at 1310 h yielded a single adult individual (22 mm SVL) of M. franki (Image 2; sex undetermined) under a medium-sized fallen log. The frog was encountered in a disturbed patch of stunted evergreen forest alongside a trail leading to Kesavanpara viewpoint (Image 4). The individual was identified based on overall coloration and external phenotypic characters mentioned in Garg & Biju (2019). These included lack of webbing between fingers; rudimentary webbing between toes; lateral surfaces from the tip of the snout up to the groin prominently dark blackish-brown; two prominent dark blackish-brown ‘false-eye’ spots on either side of the groin extending just above the hind legs; a thin mid-dorsal line extending from the tip of the snout up to the vent; ventral surfaces of throat, belly, arms, and legs dark with multiple greyish-white blotches and speckles. Other species of anurans recorded in sympatry were Clinotarsus curtipes, Duttaphrynus sp., Raorchestes sp., and frogs of the family Ranixalidae.

The current distribution point for M. indicus is approximately 37 km north-west from its closest reported locality at Valparai, Tamil Nadu State. Most other distribution points for the species occur south of the Palghat gap (PG from here on) (Figure 1), a significant biogeographic barrier for amphibians in the Western Ghats (Biswas & Karanth 2021). Only two distribution locations north of the PG are known for this frog. While Beddome (1880) mentions its occurrence in Walaghát (present day Walakkad, around Silent Valley National Park), Rajkumar et al. (2021) report its presence from Wayanad without any precise locality. These two localities are ca. 80 km and 140 km north of Nelliyampathy, respectively. The distribution of M. franki in Nelliyampathy is also notable for a similar reason. Suganthagiri, the only other known locality for this species in the Wayanad plateau, is ca. 132 km north of Kesavanpara, surmounting the PG. Thus, Nelliyampathy is now the only place south of PG where these two species of anurans occur in sympatry. Further field investigations might also yield these species in sympatry/syntopy in the Wayanad-Walakkad region north of PG. It would be interesting to look at the ecology and genetic structure of M. indicus north of the PG and M. franki south of PG to understand if these populations are indeed homogenous. Alternately, it is likely that the populations of M. indicus and M. franki on either side of the gap might represent cryptic allopatric species forming a part of a larger species complex. Another interesting observation is the presence of M. franki in the disturbed patch of forest near Kesavanpara viewpoint. It further supports the existence of this enigmatic species around human settlements (Garg & Biju 2019).

Table 1. Previous locality records of Melanobatrachus indicus.

	Locality	Year	References
1	Anamalai, Tamil Nadu	1878, 2013	Beddome (1878); Kanagavel & Tapley (2013)
2	Walaghát (present day Walakkad), Kerala	1880	Beddome (1880)
3	Valparai, Tamil Nadu	1928, 2000	Roux (1928), Ishwar 2000
4	KMTR, Tamil Nadu	1997	Vasudevan (1997)
5	Periyar Tiger Reserve, Kerala	1997	Daltry & Martin (1997)
6	Matthiketan Shola, Kerala	2007, 2021	Nixon & Bhupathy (2007); Rajkumar et al. (2021)
7	Marayoor, Kerala	2013, 2017	Rajkumar et al. (2021); Palot & Sureshan (2017)
8	Chinnar Wildlife Sanctuary, Kerala	2015	Rajkumar et al. (2021)
9	Eravikulam National Park, Kerala	2015	Rajkumar et al. (2021)
10	Wayanad, Kerala	2016	Rajkumar et al. (2021)
11	Parambikulam Tiger Reserve, Kerala	2021	Newspaper article (https://www.thehindu.com/news/national/kerala/18-new-amphibian-species-found-in-parambikulam/article38111812.ece)

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References

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