---
title: Exquisite Bivalved Snail (Julia exquisita)
scientific_name: Julia exquisita
common_name: Exquisite Bivalved Snail
taxon: Sap-sucking slugs
published: 2026-08-07T16:29:44.210Z
updated: 2026-08-20T17:09:46.280Z
tags: Exquisite Bivalved Snail, Julia exquisita, Sap-sucking slugs, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/molluscs/sap-sucking-slugs/exquisite-bivalved-snail
---

# Exquisite Bivalved Snail (*Julia exquisita*)

## Quick facts

- **Group:** Sap-sucking slugs (*Sacoglossa*)
- **Size:** up to 8 mm
- **Depth:** 0-10 m
- **Diet:** Herbivore
- **Activity:** Nocturnal
- **Rarity:** Rare
- **Habitat:** On Caulerpa in sheltered shallows
- **Reproduction:** Egg layer, Simultaneous hermaphrodite

## How to recognise it

- a snail inside a two-part shell, like a tiny green clam
- shell translucent green, matching the weed
- under 1 cm, on Caulerpa fronds
- hinged shell opens like a bivalve

A snail that looks like a clam. Under 8 mm (0.3 in), it lives inside a translucent green shell of two hinged halves that open and close exactly as a bivalve's do - and yet the animal inside is a gastropod, a sea slug relative that drains algal cells with a single-toothed radula.

The family carrying this arrangement was known from fossils and empty shells long before anyone found a living one, and the shells were filed as small clams for decades; the discovery that they belonged to a snail rearranged a chunk of the textbook. The shell grows as two valves from a single larval coil, so the resemblance is convergent rather than inherited. It lives on Caulerpa, color-matched to the frond, and at this size on green weed it is effectively invisible - most records come from sorting algae in a tray rather than from spotting one underwater.

## Also known as

- **Japanese:** ユリヤガイ
- **Russian:** Юлия изящная
- **SLK:** júlia lastúrnatá

## Scientific synonyms

- *Julia borbonica* (Deshayes, 1863)
- *Prasina borbonica* Deshayes, 1863

## Range

Hawaiian Islands, New Zealand

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/molluscs/sap-sucking-slugs/exquisite-bivalved-snail)*
*Updated: August 20, 2026*