20 March,2025 07:34 AM IST | Mumbai | Ranjeet Jadhav
Indothele amboli, a spider species named after the area where it was discovered in Maharashtra; (right) Indothele silentvalley, which was named after its location of discovery in Kerala
Two new spider species have been discovered at Amboli in Maharashtra and Silent Valley National Park in Kerala, while another researcher has identified the male of a previously known species from the Northern Western Ghats Satara and Sindhudurg districts.
A research paper titled "Revision of Indian Ischnothelidae (Arachnida: Araneae) and Descriptions of Two New Species of Indothele Coyle, 1995" was published in the European Journal of Taxonomy. The lead authors are Rishikesh Tripathi, Gautam Kadam, Danniella Sherwood, and Ambalaparambil V Sudhikumar.
Speaking to mid-day, lead author Rishikesh Tripathi highlighted the significance of the discovery, describing two new species of the genus Indothele - Indothele amboli sp. nov. from Amboli and Indothele silentvalley sp. Nov. from Silent Valley National Park. "In addition, the paper provides the first description of the male of I. mala and resolves a long-standing taxonomic confusion by transferring Ischnothele indicola to the genus Macrothele," he said.
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"The study corrects misidentifications, such as the confusion between I. mala and I. dumicola, and refines the catalogue of the family Ischnothelidae in India. This is vital for biodiversity inventories and future ecological and evolutionary studies," he explained.
Tripathi further noted that the discovery sheds light on the unique distribution of Indothele species, which are endemic to the Indian subcontinent. "The differentiation between mainland species and the island-endemic I. lanka from Sri Lanka offers a valuable case study of how geographical isolation and environmental factors shape evolution," he added.
Spiders play a crucial ecological role as natural pest controllers. Tripathi said, "As efficient predators, they regulate insect populations, reducing potential pest outbreaks. Their contribution to energy flow in food webs and nutrient recycling benefits soil health and plant growth. Moreover, due to their sensitivity to habitat changes and pollutants, spiders serve as bioindicators, offering insights into ecosystem health."
Another significant discovery, the previously unknown male of Habrocestum mookambikaense (Araneae: Salticidae: Hasariini), was documented in a research paper published in the Arachnology Journal. Lead author Rajesh V Sanap, along with Gautam Kadam, Rishikesh Tripathi, and John T D Caleb, contributed to the study.
According to wildlife researcher Rajesh Sanap, the species was originally identified in Karnataka based solely on a female specimen. "Our study extends its known range northward by approximately 430 km, with new records from Satara and Sindhudurg districts. This suggests a broader distribution of the genus Habrocestum in India than previously recognised," Sanap explained.
"The extended distribution highlights the need for further surveys in the Western Ghats, a biodiversity hotspot, to document spider diversity more comprehensively," he said.
Describing the male spider, Sanap detailed its brown carapace covered in fine black hairs, a distinct lateral band of white hairs, and a trapezoidal eye field with black and rusty brown hairs. Its palpal organ features a cone-shaped embolus with a notch near the tip and a long, sharp Retrolateral Tibial Apophysis (RTA). The female, in contrast, has a dark brown carapace with black margins, a black eye field covered in golden brown hairs, a yellowish-brown clypeus, and an oval abdomen with faint chevron markings.
Discussing habitat, he noted that the species thrives in open grassy areas, hilltops, and shaded forest paths in Maharashtra and Karnataka.
Spiders are vital microhabitat specialists, highly sensitive to environmental changes, making them excellent indicators of ecosystem health. As key players in the food web, they control insect populations, and even minor environmental shifts can lead to drastic declines in their numbers. Protecting these creatures and their habitats is essential to maintaining biodiversity and preserving the intricate ecological balance.
