Why in news?
A dataset published in Scientific Data in April 2026 describes the exoskeleton of the green pill millipede (Arthrosphaera lutescens), a species native to India’s Western Ghats. It records the exoskeleton’s chemistry, surface structure and water repellence.
Background
Millipedes belong to the class Diplopoda within the phylum Arthropoda. Their bodies are long and cylindrical, composed of many segments, most bearing two pairs of legs. They lack venomous fangs and move slowly, feeding mainly on decaying plant material. Millipedes play an important ecological role as decomposers, recycling nutrients in soil.
Key findings of the study
- Microstructure: Using atomic force microscopy, researchers observed that the millipede’s exoskeleton is covered with microscopic peaks and valleys. Electron microscopy showed spine‑like bristles, ridges and shallow pits on the surface.
- Water repellence: The researchers measured the angle at which water droplets rest on the shell, which shows how strongly the surface repels water.
- Material properties: The shell is tough yet lightweight because of its mineral‑rich composition, which includes calcium deposits. These features help the millipede withstand pressure without adding weight.
- Applications: Understanding this natural design could inspire the development of water‑repellent surfaces in industries such as textiles, coatings and biomedical devices.
About millipedes
- There are an estimated 10,000 described species of millipedes worldwide, with thousands more yet to be catalogued.
- Unlike centipedes, which have one pair of legs per segment and are predatory, millipedes have two pairs of legs per segment and are mostly detritivores.
- They have existed for over 400 million years and are among the oldest known land animals. Their hard exoskeleton protects them from predators and prevents dehydration.
- When threatened, millipedes coil into a tight spiral and may secrete foul‑smelling chemicals or, in some species, cyanide‑rich fluids as a defence.
Source: The New Indian Express · Macalester College