Pune, 11 July(HS): For the first time, scientists from the Zoological Survey of India (ZSI) have generated

DNA barcodes for the Western Ghats endemic Malabar Spiny Tree Mouse (Platacanthomys

Lasiurus), aiding clarification of its higher-level taxonomic placement.

This is one of the collaborative efforts from the scientists of the regional centres of the Zoological Survey of India.

Dr. S. S. Talmale, Dr. K. P. Dinesh, Ms. A. Shabman of ZSI, Western Regional Centre, Pune; Dr. Jafer Palot from ZSI, Western Ghats Regional Centre, Kozhikode and Dr. K. A. Subramanian from ZSI, Southern Regional Centre, Chennai, have jointly published the findings in the latest issue of the internationally reputed peer-reviewed journal, Journal of Animal Diversity, published from Lorestan University Iran.

Although the Malabar Spiny Tree Mouse, scientifically known as Platacanthomys lasiurus, was described in 1859, it took almost 166 years to generate the genetic data for the species to understand its evolutionary history of the species.

Evolutionary studies for the molecular dating suggest the origin of the present Malabar Spiny Tree Mouse ancestors during the Eocene period (56 to 33.9 million years ago), while Platacanthomys is likely a Gondwanan relic that persisted in the Western Ghats.

A similar-looking Chinese pygmy dormouse scientifically known as Typhlomys, is known from China & Vietnam with a disjunct distribution. The ancestors of Chinese pygmy dormouse diverged during the Miocene period (23 to 5.3 million years ago).

The present Platacanthomys lineage could be a relic taking refugium in the hill ranges of the Western Ghats, whose ancestors might have gone extinct due to various geological events in the past. The two genera (Platacanthomys and Typhlomys) are not monophyletic on the phylogenetic tree, which supports separate familial placement for them.

In one of the expeditions in the southern Western Ghats, the survey team encountered a Malabar spiny tree mouse near Suryamudi, Kerala, during small mammal surveys. After the molecular Studies and specimen is made available in the National Zoological Collection (NZC) of Zoological Survey of India (ZSI), Western Regional Centre (WRC), Pune, for further studies.

Dr. Dhiriti Banerjee, Director, Zoological Survey of India, said that “fresh scientific research on historically described enigmatic species like Platacanthomys is vital amid rapid climate change. Integrative approaches are key to informing conservation strategies and ensuring the species' long-term survival.

Lead author Dr. S. S. Talmale stated that habitat degradation is the key threat to the Malabar Spiny Tree Mouse in the Western Ghats. The species ranges from 50m to 2270m in altitude and is listed as Vulnerable on the IUCN Red List due to its patchy distribution. It is also protected under Schedule II of the Wildlife (Protection) Amendment Act, 2022, underscoring the need for targeted habitat conservation.

Dr. K.A. Subramanian, co-author of the studies, says, “The study reveals the existence of ancient lineages of fauna in the southern Western Ghats, highlighting its role as a tropical refugia during the break-up of the Gondwana super continent”.

Dr. M.J. Palot, co-author, noted that the Malabar Spiny Tree Mouse is a rare and elusive Western Ghats endemic. “Despite years of fieldwork, I’ve seen it only a few times. Finding a fresh specimen in Suryamudi, Aralam WLS, was a rare chance. Decoding its DNA was special, it reveals ancient origins and highlights the urgent need to protect its fragile habitat”.

Dr. K. P. Dinesh emphasised that “molecular tools like DNA barcoding and phylogenetics are vital for relict species like the Malabar Spiny Tree Mouse, revealing evolutionary history and aiding precise taxonomy and conservation in biodiversity hotspots like the Western Ghats”.

The information about Spiny Tree Mouse is an ancient relic species, is going to add more conservation value among the general public; the molecular dating information regarding the Miocene origin is going to evoke more research questions among the students and researchers, says the study team.

Hindusthan Samachar / Manohar Yadavatti