ZSI Discovers Two New Marine Nematode Species off Tamil Nadu Coast

Why in News

Scientists from the Zoological Survey of India (ZSI) have discovered two new species of free-living marine nematodes from the Tamil Nadu coastline: Corononema dhriti and Epacanthion indica. The discovery, formally published in April 2026, adds to India’s documented marine biodiversity and highlights the largely unexplored diversity of meiofauna (microscopic seafloor organisms) in Indian coastal waters.

The Two New Species

1. Corononema dhriti

2. Epacanthion indica

What Are Marine Nematodes?

Nematodes (roundworms) are one of the most abundant and diverse animal groups on Earth. Marine nematodes specifically are:

• Free-living (not parasitic) microscopic worms in the meiofauna size range (0.1–1 mm)
• Found in benthic marine sediments — from intertidal beaches to deep-sea floors
• Critical to nutrient cycling: they feed on bacteria, fungi, and organic matter, remineralising nutrients back into sediment
• Bioindicators of sediment health — pollution, dredging, or coastal development alters nematode community structure
• Most diverse metazoan group in marine sediments (up to 10,000 individuals per 10 cm² in healthy sediments)

Significance of the Discovery

For Indian Marine Biodiversity

• India’s 7,516 km coastline and Exclusive Economic Zone (EEZ) of 2.37 million km² contain rich but poorly documented biodiversity
• Most marine biodiversity surveys focus on visible organisms (fish, corals, turtles); meiofauna remain systematically under-sampled
• Both species represent new genus-level records or significant geographical range extensions

For ZSI’s Role

The Zoological Survey of India (ZSI), established in 1916, is mandated to:

• Survey and document faunal diversity of India
• Maintain the National Zoological Collections (~1 million specimens)
• Publish descriptions of new species under the International Code of Zoological Nomenclature (ICZN)

Taxonomy and Naming

Under the ICZN (International Code of Zoological Nomenclature), the rules for species naming include:

• Binomial nomenclature — Genus + species epithet (Linnaeus, 1758)
• Priority rule — first valid published name holds
• Types (holotypes) deposited in institutional collections (ZSI repository)

Marine Biodiversity in India — Key Facts

UPSC Relevance

GS Paper 3 — Environment

• Biodiversity documentation — ZSI, BSI, FSI roles
• Marine biodiversity and India’s coastal conservation obligations
• Biological Diversity Act, 2002 and Nagoya Protocol — ABS (Access and Benefit Sharing) implications for newly discovered species
• Benthic ecosystems and meiofauna as environmental indicators

Prelims Angle

• Names and characteristics of new species (ZSI discoveries are standard Prelims fodder)
• ZSI’s founding year (1916) and headquarters (Kolkata)
• Difference between nematoda and other invertebrate phyla

Facts Corner