Environment and ecology New freshwater crab genus identified Scientists have identified a new genus and species of freshwater crab from the Shevaroy Hills, Yercaud (Salem district, Tamil Nadu). The newly described genus is Patithelphusa, and the species is Patithelphusa yercaudensis. The discovery was made during a zoological survey by researchers from the Zoological Survey of India (ZSI), Kolkata, and Pukyong National University, South Korea. The genus Patithelphusa is named in honour of Sameer Kumar Pati, a distinguished Indian taxonomist known for his work on freshwater crabs. Distinct features: broader carapace, triangular lobes, and unique male reproductive structures, differing from related genera like Baratha, Vanni, and Vela. The species’ evolution was likely influenced by topographical isolation of the Shevaroy Hills, separated by deep valleys and the Cauvery River system, which limited gene flow. Highlights the Shevaroy Hills as a potential refuge for endemic species in the Eastern Ghats. With this discovery, India now records 112 freshwater crab species, belonging to 31 genera under the family Gecarcinucidae. India contributes nearly 10% of the world’s freshwater crab diversity, with many species endemic to small habitats. Cloud Seeding On October 28, 2025, IIT-Kanpur conducted a cloud seeding experiment over New Delhi using a Cessna aircraft, aiming to reduce air pollution through artificial rain. The team dispersed 10 kg of a mixture of silver iodide (20%), rock salt, and common salt, fired into the clouds using flares manufactured in Sivakasi, Tamil Nadu. IMD shared general weather inputs but did not recommend proceeding due to insufficient cloud moisture (<15%). About Cloud Seeding Cloud seeding is a weather modification technology that artificially stimulates rainfall by spraying chemical substances into the air that serve as cloud condensation nuclei. It involves dispersing substances such as silver iodide, potassium iodide, sodium chloride, or dry ice (solid CO₂) into clouds using…
