A team of researchers have identified a new species of rock dwelling large-bodied gecko from the Pakkamalai hills near Gingee in the southern Eastern Ghats in Villupuram district. This is said to be the first ever sighting of this gecko and the new species has been named as Hemidactyluspakkamalaiensis, after the hill where it was recorded.
A team of researchers led by V. Deepak, Surya Narayanan, P. Christopher, K. Raman, S. Vimalraj, Prabhu N. Ponmudi, N. Mukherjee and M. Lenin discovered the gecko during an expedition in the hills. The findings have been published in the latest issue of Vertebrate Zoology, an international journal.
The gecko measures 104 mm from snout to vent (10.4 cm) and is light brown in colour. The genus Hemidactylus goldfuss has 188 species of which 54 are known from India. Members of this group are primarily known to inhabit gigantic boulders. The new species can be easily distinguished from other geckos in the region by its large size and prominent tubercles on the body.
Of the 54 species recorded from India, as many as nine species are restricted to the Western Ghats, while the rest are distributed throughout peninsular India. The species discovered off Gingee now increases the total number of species of Hemidactylus in India to 55.
According to V. Deepak, a herpetologist and scientist of University of Wolverhampton who was part of the expedition, “We first spotted the gecko in 2022. This was followed by months of study, which included analysing the morphological features of one of these three undescribed lineages, utilizing fresh materials from the Gingee hills in the southern Eastern Ghats, followed by molecular analysis. Based on the findings, we realized that it was a new species.”
Mr. Deepak adds, “The new species is altogether different from other large-bodies congeners (organisms of the same genus) by several non-overlapping morphological characteristics. Although Hemidactylus pakkamalaiensis is genetically related to H. easai and H. graniticolus, it differs significantly from these closely related species by having fewer femoral pores, with a count of 19-21 as compared to 24-28 in the two latter species.”
“The Gingee hills are characterized by a significant presence of gigantic rock boulders that provide a suitable micro-habitat for rock-dwelling geckos. These hills are unique in this regard, and despite being situated in the drier part of peninsular India, Pakkamalai hill is home to a diverse range of vegetation types, including the distinctive Tropical Dry Evergreen Forests,” said R. Surya Narayanan, a researcher from Ashoka Trust for Research in Ecology, and the Environment (ATREE).
“This combination of vegetation and the microhabitats availability likely provided an ambient microclimatic condition that facilitated the diversification of this species. However, our survey found that H. pakkamalaiensis was present in all types of habitats. This species is also nocturnal”, Mr. Narayanan added.
According to S. Vimalraj, a naturalist, “The Pakkamalai hills boasts a rich tapestry of rare and endangered flora and fauna and the recent discovery of the gecko further contributes to its ecological significance. The region is an ecological treasure and should be conserved.”
According to K. Raman of Indigenous Biodiversity Foundation (IBF), a Puducherry based non-profit organisation, “Several endemic, endangered and critically endangered flora and fauna have been recorded in Pakkamalai hills over the years, which shows the abundant biodiversity in the region.”
