Unveiling the Deccan’s Hidden Scaled Treasures: Researchers Discover Two New Gecko Species in Telangana

HYDERABAD, INDIA — In a significant boost to India’s herpetological inventory, a collaborative team of wildlife researchers has formally described two new species of gecko from the state of Telangana. Belonging to the widely distributed genus Hemidactylus, these newly identified reptiles were unearthed within the ancient landscapes of the Central Plateau in the Deccan Peninsula.

The discovery not only underscores the remarkable, yet often overlooked, biodiversity nestled within India’s semi-arid scrublands and rocky outcrops, but it also highlights the critical importance of localized taxonomic surveys in regions facing rapid anthropogenic pressures. The findings were officially detailed in a comprehensive research paper published in the European Journal of Taxonomy.

Main Facts: Meet the New Additions to the Hemidactylus Genus

The newly discovered geckos belong to the Hemidactylus brookii group, specifically aligning with the murrayi clade. Named Hemidactylus cairnicola and Hemidactylus koyaorum, these cryptic species have evolved specialized physical and behavioral traits that allow them to thrive in their respective microhabitats.

Hemidactylus cairnicola: The Cairn-Dwelling Camouflage Expert

Discovered primarily in the Nalgonda district of Telangana, Hemidactylus cairnicola is a medium-sized gecko, measuring up to 49 millimeters in snout-to-vent length. It possesses a relatively stout, slightly depressed body paired with a robust head that is distinctly separated from its neck.

• Scalation and Morphology: The dorsal side of H. cairnicola features a granular scale matrix intermixed with enlarged, strongly keeled, conical tubercles. These are neatly arranged in 13 to 15 longitudinal rows stretching from the occiput to the base of its tail. On its underside, the belly displays approximately 31 to 32 scale rows across its width, alongside 137 to 145 longitudinal ventral scales. Males are distinguished by the presence of seven or eight femoral pores on each side.
• Habitat and Distribution: Currently known exclusively from its type locality in the Nalgonda District, this species makes its home among rocky outcrops, rocky scrub forests, and adjacent agricultural layouts. It has a distinct affinity for black rock cairns and exposed stone surfaces. Its coloration—ranging from light-brown to gray—serves as an exceptional camouflage tool, shifting dynamically to match its rocky background. The head features several distinct dark spots alongside paired preocular and postocular streaks, while irregular dark markings ripple across the body and tail. The underside remains lighter and completely unpatterned.
• Behavior and Ecology: H. cairnicola is primarily nocturnal. During the daylight hours, it retreats deep into dark rock crevices to avoid the heat and potential predators. As night falls, it emerges to hunt for insect prey. However, researchers have also observed individuals basking or resting on exposed rocks during cooler winter days and rainy periods. Its range often overlaps with human settlements, frequently found near villages and traditional Lambada communities, where it shares its habitat with a diverse array of reptiles, including other geckos, skinks, agamid lizards, and the Indian sand boa (Eryx johnii).

Hemidactylus koyaorum: The Deccan Endemic

Endemic to the Deccan Peninsula biogeographic zone, the second new species, Hemidactylus koyaorum, is currently documented solely from its type locality in the Warangal district of Telangana.

Like its counterpart, it falls within the Hemidactylus brookii complex and the murrayi clade. Morphological and genetic assessments indicate that it is most closely allied with Hemidactylus treutleri. However, mitochondrial ND2 gene sequencing has laid bare a profound genetic divide, revealing an uncorrected sequence divergence of 7.0% to 13.5% between H. koyaorum and H. treutleri. Furthermore, genetic profiling confirms that the two newly discovered species—H. cairnicola and H. koyaorum—are separated by a significant 9.5% to 10.0% sequence divergence, cementing their status as distinct, independent evolutionary lineages.

Chronology: The Journey from Field Discovery to Taxonomic Validation

The path to describing Hemidactylus cairnicola and Hemidactylus koyaorum is the culmination of meticulous field expeditions, rigorous molecular analysis, and extensive museum-based anatomical reviews. While the exact timeline of individual field encounters spans several years of regional herpetological surveys across Telangana, the formal scientific process followed a structured trajectory:

• Phase I: Fieldwork and Exploratory Surveys (2018–2022): Herpetologists traversing the rocky terrain and scrub forests of the Nalgonda and Warangal districts noted morphological variations among local geckos traditionally lumped under broader species complexes like H. brookii or H. treutleri. Recognizing potential cryptic species, researchers collected voucher specimens and tissue samples under strict regulatory protocols.
• Phase II: Laboratory Analysis and Molecular Sequencing (2022–2023): Tissue samples were subjected to advanced genetic testing. Researchers targeted mitochondrial DNA markers, specifically the NADH dehydrogenase subunit 2 (ND2) gene, to run phylogenetic analyses. The resulting dendrograms and uncorrected pairwise distance matrices provided the empirical backing needed to distinguish the populations from known sister taxa.
• Phase III: Morphological Examination and Biometric Comparisons: Concurrently, researchers examined scale counts, pore configurations, body proportions, and color patterns under high-powered stereomicroscopes at institutional facilities. These physical attributes were cross-referenced against historical type specimens housed in national and international repositories.
• Phase IV: Formal Description and Peer Review (2023–2024): Synthesizing the genetic divergence data with distinct morphological traits, the multi-institutional research team drafted the taxonomic manuscript. Following rigorous peer review by independent experts, the paper was accepted and published in the European Journal of Taxonomy, officially introducing H. cairnicola and H. koyaorum to the scientific community.

Supporting Data: Taxonomic Framework and Research Team

The discovery of these two reptiles highlights the strength of cross-institutional scientific collaboration in India. The research team comprises prominent herpetologists and conservation scientists affiliated with premier national institutions:

1. Bharath Bhupathi — Freshwater Biology Regional Centre, Zoological Survey of India, Hyderabad, Telangana.
2. Sumidh Ray — Post Graduate Department of Zoology, Fakir Mohan University, Balasore, Odisha.
3. B. Laxmi Narayana — Zoological Survey of India, FPS Building, Indian Museum Campus, Kolkata, West Bengal.
4. Amirtha Balan — Nehru Zoological Park, Bahadurpura, Hyderabad, Telangana.
5. Deepa Jaiswal — Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand.
6. Pratyush P. Mohapatra — Freshwater Biology Regional Centre, Zoological Survey of India, Hyderabad, Telangana.

Taxonomic Citation

The formal paper, titled "Two new cryptic species of Hemidactylus (Reptilia: Gekkonidae) allied to H. treutleri from Telangana, India," is publicly accessible. Researchers, students, and wildlife enthusiasts can review the complete data set, including phylogenetic trees and paratype/holotype repository numbers, directly on the European Journal of Taxonomy website.

Official Responses and Expert Perspectives

The formal recognition of Hemidactylus cairnicola and Hemidactylus koyaorum has drawn praise from the Indian conservation and scientific community, sparking important conversations regarding the state of lesser-known vertebrate biodiversity in the Deccan Plateau.

Speaking on behalf of the collaborative team, lead researchers emphasized that the discovery of cryptic species—organisms that look virtually identical to known species but are genetically distinct—points to a profound knowledge gap in Indian herpetology.

"For decades, widespread taxa like the Brook’s gecko group served as ‘catch-all’ categories for numerous distinct populations scattered across the subcontinent," noted a senior researcher involved in the study. "By integrating modern molecular tools with classical morphology, we are slowly peeling back the layers of this taxonomic complexity. What we once thought was a single, highly adaptable lizard is frequently turning out to be a complex web of micro-endemic species shaped by the ancient geological history of the Deccan."

Conservationists and forest department officials in Telangana have similarly welcomed the findings. Representatives from regional zoological parks and wildlife institutes noted that these discoveries provide invaluable baseline data for regional conservation planning. Because both species occupy restricted geographical ranges—H. cairnicola in Nalgonda and H. koyaorum in Warangal—their discovery elevates the conservation value of unprotected or semi-disturbed scrub forests that are routinely subjected to land-use changes, stone quarrying, and agricultural expansion.

Implications: Conservation, Biodiversity, and Future Horizons

The discovery of Hemidactylus cairnicola and Hemidactylus koyaorum carries profound implications for wildlife conservation, environmental policy, and ecological research in India.

1. Rewriting the Biodiversity Map of the Deccan Peninsula

The Deccan Plateau, one of the oldest geological formations on Earth, is frequently overshadowed by the biodiversity hotspots of the Western Ghats and the Himalayas. However, discoveries of micro-endemic reptiles like H. cairnicola and H. koyaorum prove that the semi-arid central plateau harbors unique evolutionary lineages. These reptiles have adapted to specialized niches, such as exfoliating granite boulders, black rock cairns, and dry thorn forests. Recognizing these species shifts the paradigm from broad-stroke conservation to targeted micro-habitat preservation.

2. The Threat of Habitat Fragmentation

Because both species are currently known only from their respective type localities, their restricted ranges render them vulnerable to localized environmental disruptions. Rapid urbanization, infrastructural expansion, local stone-crushing industries, and agricultural intensification threaten the rocky outcrops they call home. When a species is restricted to a few isolated hills or scrub patches, the destruction of a single outcrop can spell local extinction before science even fully understands the organism’s ecological role.

3. A Call for Integrated Taxonomic Research

The success of this study underscores the necessity of combining classical morphological taxonomy with cutting-edge molecular genetics. Cryptic species cannot be identified by the naked eye alone; internal genetic markers like mitochondrial ND2 are critical for unmasking hidden biodiversity. Experts are now calling for increased funding and institutional support for systematic surveys across underexplored districts of Telangana and neighboring states.

4. Directing Local Conservation Action

Armed with this new data, state wildlife authorities and local conservation groups are better positioned to advocate for the protection of fragile scrub and rock ecosystems. Engaging rural communities and traditional settlements—such as the Lambada communities near which H. cairnicola thrives—will be vital in fostering community-led conservation initiatives that safeguard these nocturnal hunters and their fragile habitats for generations to come.

As researchers continue to analyze specimens and comb through the rugged landscapes of peninsular India, the discovery of Hemidactylus cairnicola and Hemidactylus koyaorum serves as a compelling reminder that our natural world still holds countless secrets, waiting quietly in the shadows of the rocks.