---
title: "Pile Worm"
description: "Nereis vexillosa — Other animals. Nereis vexillosa, the mussel worm, belongs to the phylum Annelida, a group known as the segmented worms."
canonical: https://animalchecklist.com/animal/pile-worm
last_updated: 2026-09-20
---

# Pile Worm

> Nereis vexillosa — Other animals. Nereis vexillosa, the mussel worm, belongs to the phylum Annelida, a group known as the segmented worms.

- Scientific name: *Nereis vexillosa*
- Category: `other` (Other animals)
- Habitats: `sea` (Sea & coast)
- iNaturalist observations: 1335
- Wikidata: [Q2384850](https://www.wikidata.org/wiki/Q2384850)
- iNaturalist taxon: [81790](https://www.inaturalist.org/taxa/81790)

## Names

- en: Pile Worm

## Countries with the most observations

US (304), CA (237)

## Summary

Nereis vexillosa, the mussel worm, belongs to the phylum Annelida, a group known as the segmented worms. It is generally iridescent green and can reach 30 cm in length. It can be distinguished by the size of the upper ligules on the notopodia of the posterior region of the body. The upper ligules are much larger than the lower ligules. It is also without a collar-like structure around the peristomium.

Text: Wikipedia (en), CC BY-SA 4.0 — https://en.wikipedia.org/wiki/Nereis_vexillosa

## Photo

![Pile Worm](https://animalchecklist.com/img/animals/pile-worm/medium.jpg)

Photo: Spencer Quayle · CC0 · inaturalist — https://www.inaturalist.org/observations/178399198

## Machine access

`GET https://animalchecklist.com/api/v1/animals/pile-worm?lang=en` — see [openapi.json](https://animalchecklist.com/openapi.json).