[Herpetology • 2024] Tree Holes to Trash: Unique Upside-down Terrestrial Spawning, Agonistic Interactions, Complex Mating Calls, and Unnatural Breeding Alterations in Minervarya charlesdarwini (Anura: Dicroglossidae)

Charles Darwin's Frog (Minervarya charlesdarwini) from the Andaman Islands of India

in Biju, Garg, Gokulakrishnan, Sivaperuman, Upadhyaya, Bee et Hanken, 2024. 

DOI: 10.3099/0006-9698-577.1.1

Abstract

Anuran amphibians exhibit the greatest diversity of reproductive modes among tetrapod vertebrates. The Andamanese Charles Darwin's frog, Minervarya charlesdarwini, is the only species of the family Dicroglossidae that is known to naturally deposit eggs in water-filled cavities of tree holes or buttresses, where they then undergo exotrophic development. We describe the reproductive behavior in this species that involves a unique combination of traits: (1) Males produce complex advertisement calls comprising at least three different call types, in addition to a type of aggressive call. (2) Unpaired males exhibit agonistic interactions with each other and with mated pairs. (3) Mate selection, amplexus, and oviposition take place inside water-filled cavities. (4) During axillary amplexus, mating pairs synchronously switch between head-up and head-down positions above and below the water surface using both forward and backward movements. (5) At the time of egg laying, amplectant pairs are in an upside-down position on the cavity walls with their bodies completely outside the water. (6) Eggs are deposited over multiple bouts on the inner walls of the cavities and terrestrially above the water surface. Upside-down spawning in M. charlesdarwini is a unique trait among phytotelm-breeding terrestrial frogs. The combination of terrestrial oviposition sites in water-filled phytotelmata and the upside-down egg-laying posture is a novel report for the family Dicroglossidae and perhaps all anurans. This specialized behavior is also likely derived for a species that is embedded in a group of largely aquatic-breeding minervaryan frogs. Although M. charlesdarwini appears to be an obligate phytotelm breeder, individuals were often observed breeding inside cylindrical, water-filled plastic sapling bags in plant nurseries adjacent to fragmented forest patches, or in rain-filled discarded plastic, glass, or metal containers left as trash at the forest edge. Use of such unnatural breeding sites is likely a forced behavioral shift in response to rapidly changing forest landscapes associated with recent habitat loss and fragmentation. Our findings call for conservation attention to this habitat specialist, which, although locally abundant, is an endemic and threatened species of the Andaman Islands.

KEYWORDS: Amphibia, amplexus, Andaman and Nicobar Islands, bioacoustics, conservation, frog behavior, oviposition, phytotelm breeding, reproductive mode

A breeding pair of Charles Darwin's Frog (Minervarya charlesdarwini) from the Andaman Islands of India.

photo: S.D. Biju

A male Charles Darwin's frog calling from an unnatural breeding site: a rain-filled metal food tin littered on the forest floor.

photo: G. Gokulakrishnan

 

S. D. Biju, Sonali Garg, G. Gokulakrishnan, Chandrakasan Sivaperuman, RadhaKrishna K. Upadhyaya, Mark A. Bee, and James Hanken. 2024. Tree Holes to Trash: Unique Upside-down Terrestrial Spawning, Agonistic Interactions, Complex Mating Calls, and Unnatural Breeding Alterations in Minervarya charlesdarwini (Anura, Dicroglossidae). Breviora. 577(1), 1-33. DOI: doi.org/10.3099/0006-9698-577.1.1

[Herpetology • 2022] Minervarya charlesdarwini • The Curious Case of Charles Darwin’s Frog, Rana charlesdarwini Das, 1998: Phylogenetic Position and Generic Placement, with Taxonomic insights on Other Minervaryan Frogs (Dicroglossidae: Minervarya) in the Andaman and Nicobar Archipelago

Minervarya charlesdarwini (Das, 1998),   

in Garg, Chandrakasan, Gokulakrishnan, ... et Biju, 2022. 

 Charles Darwin’s minervaryan frog  ||  DOI: 10.3897/vz.72.e79496 

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Abstract

Since the description of Charles Darwin’s frog as Rana charlesdarwini in 1998, its generic placement has been a taxonomic enigma. Subsequent studies first transferred this species to the dicroglossid genus Limnonectes, and then considered it as a ceratobatrachid of the genus Ingerana, which has since been moved to the family Dicroglossidae. However, recent works have doubted this generic placement and also suggested the possibility of its sister relationship with the genus Liurana, within Ceratobatrachidae. Nonetheless, there have been no detailed investigations to ascertain the generic placement of this taxon by confirming its phylogenetic position or using integrative taxonomic approaches. Here, we provide the first molecular assessment of Ingerana charlesdarwini based on mitochondrial and nuclear DNA and reveal that it is nested in the dicroglossid genus Minervarya. A member of the Minervarya andamanensis species group, Minervarya charlesdarwini comb. nov. is sister taxon to M. andamanensis and shows relatively shallow genetic distances (2.8–3.6%) in the 16S gene. Both species are widely distributed, occur sympatrically, and exhibit high morphological variations, leading to long-standing confusions with other dicroglossid frogs reported from the region. Our combined morphological and molecular studies on dicroglossid frogs sampled across the known ranges of these species suggest that reports of Limnonectes doriae (Boulenger, 1887) and L. hascheanus (Stoliczka, 1870) from the Andamans are misidentifications of the former two, pointing to the absence of genus Limnonectes from the Andaman Islands. Our study also reveals the novel record of Minervarya agricola from the Andamans, a species that appears to have been confused with Fejervarya limnocharis and Minervarya keralensis in the literature and misidentified museum specimens, and is found to be widely distributed across these islands. We further find another congener from the Nicobar group of Islands, M. nicobariensis, to be closely related to M. charlesdarwini. Similar to the case of Andaman dicroglossids, our work emphasises on the need for further studies to ascertain the taxonomic identities and generic placement of Minervarya and Limnonectes species reported from the Nicobars.

Key words: Amphibia, Ingerana, integrative taxonomy, island biogeography, Limnonectes, sympatric species

Morphological variation in skin colouration and markings observed among individuals of Minervarya charlesdarwini in the Andaman Islands.
A–N Dorsolateral views. A SDBDU 2021.4212 (♂). B–C SDBDU 2019.4059 (♀). D Not preserved. E SDBDU 2019.4006 (♂). F SDBDU 2019.3975 (♂). G SDBDU 2021.4212 (♂). H SDBDU 2019.4005 (♀). I SDBDU 2019.3968 (♀). J SDBDU 2019.4004 (♂). K SDBDU 2021.4213 (♀). L SDBDU 2020.4165 (♀). M SDBDU 2019.3946 (♀). N SDBDU 2021.4214 (♀).

Photographs: S. D. Biju, G. Gokulakrishnan & Sonali Garg.

Minervarya charlesdarwini (Das, 1998), comb. nov.

Charles Darwin’s minervaryan frog

 

Distribution: Minervarya charlesdarwini is endemic to the Andaman Archipelago of India, where we find it to be widely distributed in all the major groups of islands: North and Middle Andamans (North Andaman Is., Interview Is., Middle Andaman Is., Baratang Is., and Long Is.), South Andamans (South Andaman Is., Neil Is., Havelock Is., Boat Is., Red Skin Is., Alexandra Is., Rutland Is., and Tarmugli Is.), up to the Little Andaman Island. This species has been observed between elevations of nearly sea level up to 600 m asl (Fig. 2; Table 2).

Morphological variation in skin colouration and markings observed among individuals of Minervarya andamanensis.  A–J Dorsolateral views.
A SDBDU 2021.4206 (♀). B SDBDU 2021.4207 (♀).
C–D Not preserved (♂). E SDBDU 2020.4179 (♀). F SDBDU 2010.4178a (♀). G SDBDU 2019.4011 (♂). H SDBDU 2020.4155 (♂). I Not preserved (♂). J SDBDU 2019.3956 (♂).

Photographs: S. D. Biju, G. Gokulakrishnan & Sonali Garg.

 Minervarya andamanensis (Stoliczka, 1870)

 Andamanese minervaryan frog

Distribution: Minervarya andamanensis is endemic to the Andaman Archipelago of India, where we find it to be widely distributed in all the major groups of islands: North and Middle Andamans (North Andaman Is., Landfall Is., East Is., Paget Is., Interview Is., Smith Is., Long Is., North Passage Is., North Reef Is., Baratang Is., and Middle Andaman Is.), South Andamans (South Andaman Is., Boat Is., Alexandra Is., Tarmugli Is., Rutland Is., Neil Is., and Havelock Is.), down to the Little Andaman Island. This species has been observed between elevations of sea level up to nearly 400 m asl (Fig. 2; Table 2).

Morphological variation observed among individuals of Minervarya nicobariensis in Nicobar Islands (all males).
 A SDBDU 2021.4250. B SDBDU 2021.4249.

Morphological variation observed among individuals of Minervarya agricola.
 A Not preserved (♂). B SDBDU 2020.4151 (♂).

 Photographs: S. D. Biju, G. Gokulakrishnan and Sonali Garg.

Minervarya agricola (Jerdon, 1853) from Andaman Islands

Distribution. Minervarya agricola is a widely distributed species of South and Southeast Asia, being found in India, Sri Lanka, Bhutan, Nepal, Bangladesh, Myanmar, Thailand, and southern China (Garg and Biju 2021). In the Andaman Archipelago of India, we provide new reports of this species from all the major groups of islands: North and Middle Andamans (North Andaman Is., Baratang Is., and Middle Andaman Is.), South Andamans (South Andaman Is., Neil Is., and Havelock Is.), up to the Little Andaman Island. This species has been observed between elevations of sea level up to elevations of nearly 130 m asl (Fig. 2; Table 2).

  

 

 Sonali Garg, Sivaperuman Chandrakasan, G. Gokulakrishnan, C. Gopika, Indraneil Das and S. D. Biju. 2022. The Curious Case of Charles Darwin’s Frog, Rana charlesdarwini Das, 1998: Phylogenetic Position and Generic Placement, with Taxonomic insights on Other Minervaryan Frogs (Dicroglossidae: Minervarya) in the Andaman and Nicobar Archipelago. Vertebrate Zoology. 72: 169-199.  DOI: 10.3897/vz.72.e79496

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[Herpetology • 2022] Microhyla nakkavaram • Hiding in Plain Sight: Rain Water Puddles in Nicobar Islands of India Reveal Abundance of a New Frog Species of the Genus Microhyla Tschudi, 1838 (Anura: Microhylidae)

Microhyla nakkavaram  

Garg, Sivaperuman, Gokulakrishnan, Chandramouli & Biju, 2022

DOI: 10.6620/ZS.2022.61-02 

ZoolStud.sinica.edu.tw 

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Recent studies on frogs of the Microhyla heymonsi species complex have demonstrated that high genetic variation exists among its various known populations from regions across Asia. We assessed the taxonomic identity of the Nicobar population of Microhyla cf. heymonsi and compared it to the typical Microhyla heymonsi from Taiwan and the two recently described species in this complex from Vietnam. Our study demonstrates that the Nicobar population is both genetically and morphologically divergent and warrants recognition as a new species, which we formally describe here as Microhyla nakkavaram sp. nov. The new species is closely related to M. daklakensis, M. heymonsi, and M. ninhthuanensis, but diagnosable from all three species by a suite of morphological characters, such as the presence of two small tubercles at mid-dorsum along with ( )-shaped markings, length of finger I longer than half the length of finger II, presence of three distinct metacarpal tubercles on hand, rudimentary foot webbing, as well as its slender body shape, granular dorsal skin texture, and other colour characters and body markings. Statistical analyses based on multiple morphometric characters also clearly separate our new taxon from M. heymonsi, with which it was previously confused. Our phylogenetic analyses based on the mitochondrial 16S rRNA locus find Microhyla nakkavaram sp. nov. to be nested in the Microhyla achatina species group, where it is delimited as a distinct species. This lineage shows genetic distances of ≥ 3.5% from all the other known congeners. Currently, the known distribution of the new taxon is restricted to the southernmost group of Nicobar Islands—Great Nicobar, Kondul, and Little Nicobar—where it is found in abundance across a wide range of habitats during the monsoon season. Our study underlines the need to reassess the identity of all the known populations of M. ‘heymonsi’ from other regions in Southeast and East Asia. To facilitate future taxonomic work in the light of our and other recent findings, we also provide a detailed redescription and revised diagnosis for M. heymonsi based on morphological examination of its century-old type material originating from Taiwan.

Key words: Amphibia, Microhyla heymonsi, Integrative taxonomy, Mitochondrial DNA, Species complex.

The holotype of Microhyla nakkavaram sp. nov. (ZSI/ANRC/T/14215). 

Colour variation in life among the paratype and referred specimens of Microhyla nakkavaram sp. nov.
A–E: Paratypes: A: ZSI/ANRC/ T/14216; B: ZSI/ANRC/T/14220; C: ZSI/ANRC/T/14217; D: ZSI/ANRC/T/14218; E: ZSI/ANRC/T/14219; F: Referred specimen: SDBDU 2019.4203.
Seven aspects are depicted in clockwise order: dorsal view, ventral view, lateral view, dorsal view of cloacal region, posterior view of cloacal region, ventral view of hand, and ventral view of foot.

Photos: S. D. Biju.

Microhyla nakkavaram sp. nov. 

Nicobarese narrow-mouthed frog

Diagnosis: Microhyla nakkavaram sp. nov. is diagnosed by a combination of following morphological traits: body slender, small in size (male SVL 16–19 mm, female SVL 21 mm); snout rounded in lateral view; finger I longer than half the length of finger II: FI > ½FII; dorsal surface of finger and toe discs with a median dorso-terminal groove, cover bifurcate distally; tips of all fingers weakly dilated into discs; three metacarpal tubercles, rounded; tibiotarsal articulation of the straightened limb reaching up to the eye; rudimentary webbing between toes; both inner and outer metatarsal tubercles present; dorsum sparsely to uniformly granular, especially in life; lateral surfaces prominently dark blackish-brown from the snout to nearly the groin with ash-blue mottling towards the lower parts; a thin light coloured mid-dorsal line present from the snout tip to the vent; presence of two small tubercles at mid-dorsum with ( )-shaped markings, anterior one placed almost at the level of armpits, and posterior one almost at the center of the dorsum, both the tubercles along the mid-dorsal line (Figs. 3–4). 

Phylogenetic relationship and genetic divergence: Microhyla nakkavaram sp. nov. is a member of the Microhyla achatina species group (Microhyla heymonsi subgroup) and shows a well-supported sister group relationship with M. ninhthuanensis (Fig. 1). It differs from all the genetically known congeners by uncorrected pairwise genetic distances of ≥ 3.5% for the 16S rRNA (Table 1).  

Etymology: The species name is derived from an ancient name for Nicobar Islands—‘Nakkavaram’ (meaning: the land of naked people, in Tamil language)— that finds earliest mention in the 11th century Tanjore inscriptions from the reign of Chola dynasty. The species epithet is treated as an invariable noun in apposition to the generic name. 

Microhyla heymonsi Vogt, 1911 

Heymon’s narrow-mouthed frog

Distribution: Possibly restricted to the islands of Taiwan and Hainan; and Southern China, from Zhejiang Province in the east, through southern Sichuan Province, up to Yunnan Province in the west. 

Sonali Garg, Chandrakasan Sivaperuman, G. Gokulakrishnan, S. R. Chandramouli and S. D. Biju. 2022. Hiding in Plain Sight: Rain Water Puddles in Nicobar Islands of India Reveal Abundance of a New Frog Species of the Genus Microhyla Tschudi, 1838 (Anura: Microhylidae).  Zool Stud. 61:2. 

DOI: 10.6620/ZS.2022.61-02

 ZoolStud.sinica.edu.tw/Journals/61/61-02.html  

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[Herpetology • 2020] Megophrys awuh, M. dzukou & M. numhbumaeng • Taxonomic Review of the Asian Horned Frogs (Anura: Megophryidae: Megophrys) of Northeast India and Bangladesh previously misidentified as M. parva (Boulenger), with Descriptions of Three New Species

Megophrys (Xenophrys)  numhbumaeng 

Mahony, Kamei, Teeling & Biju, 2020

DOI: 10.1080/00222933.2020.1736679 

 Researchgate.net/publication/340981822 

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ABSTRACT

Megophrys parva is currently considered to be among the most widely dispersed species within the genus, however, recent studies have provided compelling evidence that this species represents a complex of morphologically similar, deeply divergent taxa. The focus of this paper is to take a closer look at species from Northeast India (NEI) and Bangladesh that are currently, or were until recently, considered to represent M. parva, now comprising the M. (Xenophrys) megacephala species group. We investigate their troublesome taxonomic histories, identify hidden cryptic species diversity using morphological and molecular data, and resolve many of the historical misidentifications that have led to a proliferation of taxonomic confusion in this group. Molecular analyses extend the geographic distribution of the M. (X.) megacephala species group east into northern Myanmar based on available sequence data.

A detailed redescription of the paralectotypes of M. parva is provided to better define this poorly known species. The geographic distributions of the taxonomically obscure species, M. serchhipii and M. zunhebotoensis, are extended far beyond their respective type localities, and both are considerably better defined taxonomically based on detailed descriptions of referred specimens, and comparison with relevant congeners. Significant geographic range extensions are also provided for the recently described species M. oropedion and M. megacephala. Three new species from the Indian states of Nagaland and Manipur are identified using a combination of morphological characters, supported by significant genetic divergence. Examination of historical specimen collections and scrutiny of published literature provide sufficient evidence to remove M. parva and M. wuliangshanensis from the checklist of Indian species. Previous records of M. parva from Bangladesh are demonstrated to represent M. serchhipii. Recent reports of M. glandulosa and M. robusta from Meghalaya are also revised and are considered to be based on misidentifications of known species from the state. The revised distributions of NEI’s small-sized horned frogs provide insights into the biogeography of the group. One of the newly described species known only from the high-elevation Dzükou Valley, Nagaland, might require immediate conservation action due to increased tourist activity at its type locality.

KEYWORDS: Anura, taxonomy, systematics, molecular phylogenetics, conservation

Megophrys (Xenophrys) parva (Boulenger, 1893)

Etymology. The specific epithet is Latin, derived from ‘parvus’, meaning ‘little’.

Suggested common name. Many common names have been suggested for M. parva that either describe morphological characters not found on this species (e.g. Burmese Spadefoot Toad [Frank and Ramus 1995]; Brown Spine-Eyed Frog [Nutphund 2001]), or are ambiguously descriptive (e.g. Tubercular Breasted Frog [Chanda 2002]; see Frost [2019, online] for others). We suggest ‘Little Karen Hills Horned Frog’ as the common name for this species since it is currently the only small-sized species of Megophrys named from the Karen Hills.

Megophrys (Xenophrys) ancrae Mahony, Teeling & Biju, 2013 

Suggested common name. We suggest ‘Namdapha Horned Frog’ based on the species’ type locality.

Distribution. This species is thus far known only from the type locality and surrounding foothill areas (330–790 m asl.) in Namdapha National Park and Tiger Reserve in Changlang district of eastern Arunachal Pradesh, NEI (Figure 2; Mahony et al. 2013).

Megophrys (Xenophrys) megacephala Mahony, Sengupta, Kamei & Biju, 2011

Suggested common name. Big Headed Indian Horned Frog (Mahony et al. 2011), since this species attains proportionately the largest head relative to body size of all Indian Megophrys species. 

  Megophrys awuh sp. nov. 
 adult male (SDBDU 2007.111: SVL 35.7 mm) in life
from Jakhama village, Kohima district, Nagaland state, India

Megophrys (Xenophrys) awuh sp. nov. 

Etymology. The specific epithet ‘awuh’ is treated as a noun in apposition taken from the Pochury language, meaning ‘frog’. The Pochury tribe are the native inhabitants of Meluri circle in Nagaland state, within which the type locality lies. 

Suggested common name. We suggest ‘Naga Hills Horned Frog’ for this species based on its currently known distribution.

Megophrys dzukou sp. nov.  

 adult male holotype (BNHS 6072: SVL 34.2 mm) in life, 

from Kohima district, Nagaland state, India.

Megophrys (Xenophrys) dzukou sp. nov.

Etymology. The specific epithet ‘dzukou’ is a toponym based on the type locality of Dzükou Valley. The name is treated as a noun in apposition. 

Suggested common name. We suggest ‘Dzükou Valley Horned Frog’ as a suitable English language common name. 

Megophrys numhbumaeng sp. nov.
adult male holotype (BNHS 6075: SVL 34.6 mm) in life
from Tamenglong district, Manipur state, India 

Megophrys (Xenophrys) numhbumaeng sp. nov.

Etymology. The specific epithet is treated as a noun in apposition, and the phonetic derivative of a portmanteau word ‘nwmbwmaeng’ from the Rongmei (N-ruangmei) language, the dominant tribal language in the Tamenglong district of Manipur state. The word ‘nwm-’ means forest, and ‘bwmaeng’ means spirit, alluding to the species’ phantomish nature eluding the field researchers on at least three visits to the locality in the presumably (early) breeding season. For correct pronunciation of the species epithet, ‘numhbumaeng’ (pronounced noom-boo-meng) would be the phonetic spelling of the name. 

Suggested common name. We suggest ‘Tamenglong Horned Frog’ based on the species’ type locality being in the Manipur state, Northeast India. 

Megophrys (Xenophrys) oropedion Mahony, Teeling & Biju, 2013

Suggested common name. Since this species is currently endemic to Meghalaya state, and is the smallest species found there, we suggest the common name ‘Little Meghalayan Horned Frog’

Megophrys (Xenophrys) serchhipii (Mathew & Sen, 2007) 

Etymology. According to Mathew and Sen (2007), the specific epithet ‘serchhipii’ is a toponym after the locality where the holotype specimen was collected, but it is unclear how the name was coined. If the locality name was to be treated as a noun in apposition, it would be given as ‘serchhip’, otherwise a typical genitive termination for this toponym would be -ensis (e.g. ‘serchhipensis’ meaning ‘from Serchhip’). However, the suffix -i or -ii are typically used in cases of names formed from personal names. The locality name, Serchhip, means ‘citrus[trees]-on-top [of the first hill of the then Serchhip village, which now included New Serchhip and Chhiahtlang villages]’, and so the specific epithet spelling appears to be a case of incorrect Latinisation. Since it is essentially without meaning, the name falls within the category of an ‘arbitrary combination of letters’ (ICZN 1999: Article 11.3). In any case, the original spelling cannot be emended to correspond with its originally proposed etymology (e.g. to ‘serchhipensis’), and must be retained as the ‘correct original spelling’ according to the Code (ICZN 1999: Articles 11.3 & 32.5.1).

 Suggested common name. The previously suggested common names ‘Serchhipii Horned Frog’ Dinesh et al. (2009) and ‘Serchhip’s Horned Toad’ (Mathew and Sen 2010) are based either on an arbitrary combination of letters (i.e. ‘Serchhipii’), or confusingly indicate that the name might be based on a genitive, as the spelling of the species epithet suggests (see ‘Etymology’ section above). To avoid such confusion, we suggest ‘Common Warty Horned Frog’ as a suitable and simple alternative common name for this species since it is widespread in northeast India south/east of the Brahmaputra River and is so far the only Megophrys species confirmed from Bangladesh. It is also the most tuberculate (or ‘warty’) species found in the region

 

Megophrys (Xenophrys) zunhebotoensis (Mathew & Sen, 2007)

Etymology. The specific epithet ‘zunhebotoensis’ is a toponym after the locality where the type specimens were collected. 

Suggested common name. ‘Zunheboto Horned Frog’ has been suggested by Dinesh et al. (2009). 

  

Stephen Mahony, Rachunliu G. Kamei, Emma C. Teeling and S. D. Biju. 2020. Taxonomic Review of the Asian Horned Frogs (Amphibia: Megophrys Kuhl & Van Hasselt) of Northeast India and Bangladesh previously misidentified as M. parva (Boulenger), with Descriptions of Three New Species. Journal of Natural History. 54(1-4 - Amphibian taxonomy: Early 21st century case studies); DOI: 10.1080/00222933.2020.1736679 

 Researchgate.net/publication/340981822_Taxonomic_review_of_Megophrys_of_Northeast_India_and_Bangladesh

Three new species of horned frogs discovered from the forests of Northeast India 

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[Herpetology • 2021] Duttaphrynus brevirostris, D. peninsularis & D. stomaticus • Lost, Forgotten, and Overlooked: Systematic Reassessment of Two lesser-known Toad Species (Anura, Bufonidae) from Peninsular India and Another Wide-ranging northern Species

A. Duttaphrynus brevirostris (BNHS 6126) from Kempholey Ghat region in Sakleshpur taluk. B. Duttaphrynus peninsularis (SDBDU 6370) from Wattakolli.
C–D. Duttaphrynus stomaticus: C. SDBDU 2015.2909 from Assam; D. SDBDU 2012.2170 from Rajasthan.

in Bisht, Garg, ... et , 2021. 

DOI: 10.3897/zse.97.61770

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Abstract

We rediscovered two species of toads, Bufo stomaticus peninsularis and Bufo brevirostris, which were described from Peninsular India 84 and 101 years ago, respectively, but have not been reported since. Because the name-bearing types of both species are either damaged or lost, we provide detailed redescriptions, morphological comparisons, and insights into phylogenetic relationships with closely related members of the genus Duttaphrynus sensu lato, based on new material from the type locality of each species. We clarify and validate the identity of D. brevirostris, which was rediscovered from multiple localities in the Malenadu and adjoining coastal regions of Karnataka. We also demonstrate that Bufo stomaticus peninsularis, which was considered a synonym of Duttaphrynus scaber, is a distinct species. Bufo stomaticus peninsularis differs from Duttaphrynus scaber morphologically and genetically, and is more closely related to members of the Duttaphrynus stomaticus group. We also clarify the identity of the namesake species of the Duttaphrynus stomaticus group, which is reported widely in India and neighbouring countries, but lacks sufficient taxonomic information due to its brief original description and reportedly untraceable type material. We located and studied the complete syntype series of D. stomaticus, probably for the first time in over a century, and we report on the status of available specimens, provide detailed description of a potential type, compare it to related species, and clarify the species’ geographical range. Our molecular analyses suggest that D. stomaticus is minimally divergent from, and possibly conspecific with, D. olivaceus. Our analyses also clarify its relationship to the closely-related D. peninsularis comb. nov., with which it was previously confused. Finally, our study provides other insights into the phylogenetic relationships and genetic differentiation among various species of Duttaphrynus toads.

Key Words: Amphibia, Bufo stomaticus peninsularis, distribution, Duttaphrynus brevirostris, Duttaphrynus stomaticus group, Firouzophrynus, molecular phylogeny, redescription, rediscovery, taxonomy

Topotype of Duttaphrynus brevirostris (Rao, 1937), topotype of D. peninsularis (Rao, 1920), and referred specimens of D. stomaticus (Lütken, 1864) in life.
A. Duttaphrynus brevirostris (BNHS 6126) from Kempholey Ghat region in Sakleshpur taluk.
B. Duttaphrynus peninsularis (SDBDU 6370) from Wattakolli.
C–F. Duttaphrynus stomaticus: C. SDBDU 2015.2909 from Assam; D. SDBDU 2012.2170 from Rajasthan; E. SDBDU 2012.2172 from Delhi; and F. SDBDU 2012.2268 from Bihar.

Phylogenetic relationships and genetic differentiation in the genus Duttaphrynus.
 A. Maximum Likelihood phylogenetic tree based on 5,737 bp DNA comprising nine mitochondrial gene regions and two nuclear genes, showing phylogenetic relationships between the major species-level lineages. Values above and below the branches indicate Bayesian Posterior Probabilities (BPP) and RAxML Bootstrap Support (BS), respectively;
B. Maximum Likelihood barcoding tree based on 524 bp of the mitochondrial 16S rRNA sequences. BPP and BS support values are indicated above and below the branches, respectively. Coloured vertical bars outside the terminal node labels indicate putative species delimited in the bPTP analysis;
C. Median-Joining haplotype network based on 42 haplotypes recovered from 133 sequences of the 16S gene (420 bp). Size of the coloured circles is proportional to the number of haplotypes; black circles indicate median vectors; each branch represents a single mutation step; additional mutational steps are indicated by values in parentheses; photo credits: D. crocus (Guinevere O. U. Wogan), D. olivaceus (Parham Beyhaghi), and D. dhufarensis (Todd W. Pierson).

Duttaphrynus brevirostris (Rao, 1937)

Duttaphrynus peninsularis (Rao, 1920), comb. nov.

Duttaphrynus stomaticus (Lütken, 1864)

Geographical distribution of Duttaphrynus brevirostris (dark grey), D. peninsularis (blue), and D. stomaticus (orange).

Conclusions: 

The results of this study resolve long-standing uncertainty regarding the identities and taxonomic status of two toad species described from Peninsular India. Bufo brevirostris Rao, 1937 was considered a problematic taxon, because its original name-bearing types are lost. Bufo stomaticus peninsularis Rao, 1920 was long forgotten as an available name for Peninsular Indian populations closely related to Duttaphrynus stomaticus. We substantiate D. peninsularis to be a distinct species, which is both morphologically diagnosable and phylogenetically distinct. Taxonomic redefinition of both of these species was achieved not just by examining the original literature and available types, but also through an effort to rediscover new material from each species’ respective type locality. The redescription of Bufo brevirostris Rao, 1937 based on new topotypic material, along with detailed comparisons to related taxa, objectively clarifies its identification for future reference. Similarly, topotypic material for Bufo stomaticus peninsularis Rao, 1920 enabled a detailed re-evaluation of its taxonomic status in the absence of a well-preserved type. Altogether, our results emphasise that new collections from type localities of historically available names should be attempted when taxonomic resolution is not feasible on the basis of original descriptions or type specimens (Bailey 1933; Garg and Biju 2016).

The present work clarified the taxonomic identity of another species, Duttaphrynus stomaticus, which was overlooked due to its presumed wide distribution. This taxon was known only from its brief original description, and the available, original name-bearing types remained unexamined due to literature-based misconceptions concerning their untraceability (Dutta 1997; Ganesh et al. 2020). We located the well-preserved eight original type specimens, and clarified the status of name-bearing types and the identity of this species, which we redescribed to facilitate future taxonomic studies. This action also aided our objective of resolving the taxonomic status of D. peninsularis, which was originally defined as a variety of D. stomaticus. Our results have important implications concerning the taxonomy and geographical ranges of the two species. Hereafter, D. stomaticus should be considered as a species found in the northern regions of South Asia, whereas its sister taxon D. peninsularis should be recognised as a Peninsular Indian form (Fig. 4; Suppl. materal 1: Table S3). Detailed redescriptions provided in this study will enable proper identification and range delineation, and serve as the basis for future conservation action. Knowledge of phenotypic variation and phylogenetic affinities of both species will also facilitate a better understanding of patterns of genetic differentiation within the genus, particularly among the species of the Duttaphrynus stomaticus group.

   

 Karan Bisht, Sonali Garg, A. N. D. Akalabya Sarmah, Saibal Sengupta and S. D. Biju. 2021. Lost, Forgotten, and Overlooked: Systematic Reassessment of Two lesser-known Toad Species (Anura, Bufonidae) from Peninsular India and Another Wide-ranging northern Species. Zoosystematics and Evolution. 97(2): 451-470. DOI: 10.3897/zse.97.61770

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[Herpetology • 2021] Microhyla sriwijaya • A Tiny New Species of Microhyla Tschudi, 1838 (Anura: Microhylidae) from Belitung Island and Southeastern Sumatra, Indonesia

Microhyla sriwijaya 

 Eprilurahman, Garg, Atmaja, Alhadi, Munir, Ubaidillah, Arisuryanti, Biju, Smith & Hamidy. 2021

DOI: 10.11646/zootaxa.5027.4.1

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Abstract

A tiny new species of narrow-mouthed frog of the genus Microhyla is described from the island of Belitung and southeastern Sumatra, Indonesia. The most distinctive feature of the new frog is its diminutive adult size, snout-vent length ranging only from 12.3 to 15.8 mm in adult males. Phylogenetic analyses based a fragment of the mitochondrial 16S rRNA gene, along with detailed morphological and acoustic comparison differentiate the new taxon from all known congeners. The new species, formally described as Microhyla sriwijaya sp. nov., is a member of the M. achatina species group and the sister taxon to M. orientalis. It is diagnosable from other congeners by a combination of characters: (1) smaller male snout-vent size < 16 mm; (2) snout obtusely rounded in dorsal view; (3) absence of mid-dorsal line and skin fold; (4) first finger reduced (finger I length less than half of finger II length); (5) dorsum with a prominent dark median mark extending posteriorly, narrow anteriorly near the level of the shoulder and expanding dorsolaterally up to the vent; margins of the dorsal marking concave with broad reddish-brown or orange colouration on either side; (6) foot webbing rudimentary, reaching just up to the first subarticular tubercle on all toes; (7) dorsal skin with prominent tubercles, especially in life; (8) tibiotarsal articulation of adpressed limb reaching beyond the snout tip; and (9) males produce a single type of call with pulsatile temporal structure, calls of relatively short duration ranging between 31.8–62.8 s, with two to three pulses delivered at a rate ranging between 32.2–36.0 pulses per second, and the mean overall dominant frequency of 4.3 kHz. The uncorrected pairwise genetic distances between Microhyla sriwijaya sp. nov. and all other known congeners are > 3.8% for the studied 16S gene fragment. The new species was discovered from wayside rural areas with oil palm plantations at four localities in the small island of Belitung (type locality), and from coffee plantation and secondary forest at Lampung in southeastern Sumatra. It is not known from any protected area and appears to be threatened due to tin mining activity, intensive logging, oil palm, and other commonly practiced agriculture activities.

Keywords: Amphibia, Bioacoustics, Integrative Taxonomy, Microhyla achatina group, Mitochondrial DNA, new species, Phylogeny, Southeast Asia

Microhyla sriwijaya  

Rury Eprilurahman, Sonali Garg, Vestidhia Y. Atmaja, Farits Alhadi, Misbahul Munir, Rosichon Ubaidillah, Tuty Arisuryanti, S. D. Biju, Eric N. Smith and Amir Hamidy. 2021. A Tiny New Species of Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from Belitung Island and Southeastern Sumatra, Indonesia. Zootaxa. 5027(4); 451-488. DOI: 10.11646/zootaxa.5027.4.1

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[Herpetology • 2021] Amolops adicola • Phylogenetic Position of the poorly Known Montane Cascade Frog Amolops monticola (Anura: Ranidae) and Description of A New closely related Species from Northeast India

 

Amolops adicola

Patel, Garg, Das, Stuart & Biju, 2021

 Adi Cascade Frog  ||  DOI: 10.1080/00222933.2021.1946185  

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ABSTRACT

The phylogenetic position of Amolops monticola, a cascade frog species known for over 150 years, remains unknown. Yet over the years new taxa have been frequently described in the ambiguously recognised A. monticola species group, based on morphology and presumed phylogenetic affinities. Here we report fresh collections of A. monticola from the Indian Himalayas and clarify its identity with new molecular and morphological evidence. Furthermore, our surveys in the Northeast Indian State of Arunachal Pradesh have led to the discovery of another new species in the A. monticola group from Siang River basin encompassing the Adi hills (historically known as Abor hills). The new species, formally described as Amolops adicola sp. nov., is morphologically distinguished from its congeners by a suite of characters that include adult size, body colouration and markings, skin texture, snout shape, foot webbing and digit tip morphology, in addition to significant morphometric distinctness observed in principal component analysis. Phylogenetically, the new species is recovered as a well-supported sister taxon of A. monticola, based on Bayesian and maximum likelihood inferences as well as Bayesian Poisson Tree Processes (bPTP) species delimitation analysis using 2001 bp of mitochondrial DNA (16S rRNA, cytochrome c oxidase subunit I and NADH dehydrogenase 2). It differs from other known members of the group by considerable genetic distances in the studied loci: ≥ 4.3% at 16S, ≥ 6.1% at COI and ≥ 7.0% at ND2. The study also shows for the first time the phylogenetic affinities of another Indian member of the A. monticola group, A. kohimaensis. Altogether, the new insights resolve the long-existing enigma surrounding A. monticola and facilitate a better understanding of systematic relationships within the large A. monticola species group. Our findings also emphasise the need for further dedicated studies on the cascade frogs of Northeast India.

KEYWORDS: Anura, Amolops monticola species group, Amolops kohimaensis, bioacoustics, Himalaya biodiversity hotspot, integrative taxonomy, redescription

     

Amolops adicola sp. nov. in life, 
dorsolateral view of amplected pair (paratype, BNHS 6125, female, male not preserved). 

 Amolops adicola sp. nov.

 Adi Cascade Frog

Etymology: The species name is derived from ‘Adi’ (after Adi hills and the Adi tribe that inhabits the region where the type series was collected) and Latin ‘-cola’ (meaning inhabiting or dwelling in). The species epithet adicola is treated as an invariable noun in apposition to the generic name.

Amolops adicola sp. nov. in life,
dorsolateral view (holotype, BNHS 6121, female) 

 

Naitik G. Patel, Sonali Garg, Abhijit Das, Bryan L. Stuart and S.D. Biju. 2021. Phylogenetic Position of the poorly Known Montane Cascade Frog Amolops monticola (Ranidae) and Description of A New closely related Species from Northeast India. Journal of Natural History. 55(21-22); 1403-1440. DOI: 10.1080/00222933.2021.1946185 

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