---
title: Giant Spider Conch (Lambis truncata)
scientific_name: Lambis truncata
common_name: Giant Spider Conch
taxon: Prosobranchia
published: 2026-08-11T15:43:16.967Z
updated: 2026-08-11T16:34:28.188Z
tags: Giant Spider Conch, Lambis truncata, Prosobranchia, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/molluscs/prosobranchia/giant-spider-conch
---

# Giant Spider Conch (*Lambis truncata*)

## Quick facts

- **Group:** Prosobranchia (*Prosobranchia*)
- **Size:** up to 33 cm
- **Depth:** 0-25 m
- **Diet:** Herbivore
- **Activity:** Nocturnal
- **Rarity:** Uncommon
- **Habitat:** Sand and seagrass beds beside reef
- **Reproduction:** Egg layer, Gonochoric

## How to recognise it

- massive shell with six long curved spines fanned out from the lip
- spire flattened at the top, cut off rather than pointed
- notch beside the front of the aperture where one eye looks out
- shell to 33 cm

A massive shell with six long curved spines fanned out from the lip like fingers, up to 33 cm (13 in), and a spire that looks cut off flat at the top - the truncata of the name. Empty ones sit on shelves all over the world; live ones sit half-buried on sand and seagrass beside the reef, covered in algae and easy to walk past.

A conch does not glide like other snails. The foot is narrow and ends in a hard claw-shaped operculum, which the animal jams into the sand and uses as a pole vault, throwing itself forward in a series of lurches. Watching one flee is a lesson in how little a snail resembles the animal in the diagram, and it is fast enough to be startling.

And it watches back. Each eye sits at the end of a thick stalk, with a real lens and enough resolution to react to a shape moving overhead, poking out through a notch in the shell lip built for exactly that purpose. If a stalk is bitten off - and they often are - the animal grows a new one.

## Also known as

- **English:** giant spider conch, wild-vine root
- **German:** Gemeine Spinnenschnecke, Große Teufelskralle
- **Russian:** Лямбис усечённый

## Scientific synonyms

- *Lambis (Lambis) truncata* ([Lightfoot], 1786)
- *Lambis bryonia* (Gmelin, 1791)
- *Pterocera bryonia* (Gmelin, 1791)
- *Pyrula bengalina* Grateloup, 1840
- *Strombus bryonia* Gmelin, 1791
- *Strombus truncatus* [Lightfoot], 1786

## Range

Chagos, Indian Ocean, Mascarene Islands, South Africa, Tanzania

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/molluscs/prosobranchia/giant-spider-conch)*
*Updated: August 11, 2026*