White Worm in Pond: Likely an Earthworm, Not a Parasite

Identification

A single white worm, 80 mm long, with a visible clitellum (saddle), active in water for weeks—this is a **common earthworm** (Lumbricus terrestris or similar). Earthworms can survive submerged for extended periods, especially in cool, oxygenated water. The white color is from being clean and empty-gutted.

Harmful or Helpful?

Harmless. Earthworms are detritivores; they aerate soil and break down organic matter. In a pond, they'll eventually die and become fish food. No action needed.

Fun Fact

Some earthworm species (like *Eiseniella tetraedra*) are semi-aquatic and thrive in saturated soils. They're a sign of healthy, organic-rich surroundings.

Rescue it if you like, but it's not a pest or parasite.