---
title: Green Lobiger (Lobiger viridis)
scientific_name: Lobiger viridis
common_name: Green Lobiger
taxon: Sap-sucking slugs
published: 2026-08-07T16:29:44.206Z
updated: 2026-08-30T17:46:40.707Z
tags: Green Lobiger, Lobiger viridis, Sap-sucking slugs, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/invertebrate/molluscs/sap-sucking-slugs/green-lobiger
---

# Green Lobiger (*Lobiger viridis*)

## Quick facts

- **Group:** Sap-sucking slugs (*Sacoglossa*)
- **Size:** up to 3 cm
- **Depth:** 0-15 m
- **Diet:** Herbivore
- **Activity:** Nocturnal
- **Rarity:** Rare
- **Habitat:** Caulerpa beds in calm shallow water
- **Reproduction:** Egg layer, Simultaneous hermaphrodite

## How to recognise it

- four long finger-like lobes over the back, kept rolled until disturbed
- small transparent shell visible between the lobes
- bright green with pale speckling
- on Caulerpa, especially the grape weed, never on coral
- up to 3 cm

This slug steals a chemical weapon rather than a solar panel.

Caulerpa, the grape weed it lives on, defends itself with caulerpenyne, a compound that turns sticky and toxic within seconds of the alga being damaged. Lobiger and its relative Oxynoe eat it anyway, and convert the caulerpenyne into oxytoxins that end up in their own mucus. The slug is drinking a defended plant and reissuing the defense under its own name.

It is choosy about which plant. Caulerpa species differ widely in how much of the compound they carry, and this slug works the middle of the range, on weeds like the grape Caulerpa racemosa rather than the mildest or the strongest. On a standing bunch of it a bright green 3 cm slug is close to invisible.

The four finger-like lobes on its back are the second line. They are usually carried rolled up, and a disturbed animal flicks them open, which roughly doubles its apparent size and shows color patches that were not there a moment before. Push it further and the lobes come off altogether, exuding a sticky secretion and writhing on the spot while the slug crawls away. They grow back.

Between the lobes sits a small transparent shell, too small to withdraw into and no use as armor, left over from ancestors that had a proper one. What this animal does not have is the family's famous trick: when photosynthesis was measured across the sacoglossans, Lobiger viridis registered zero. It drains Caulerpa cells and digests what it takes, chloroplasts included.

Search calm shallow bays with standing Caulerpa, mostly after dark, and expect to find nothing on most attempts.

## Also known as

- **English:** Blue-striped Leafsnail
- **Russian:** Лобигер зелёный

## Scientific synonyms

- *Lobiger picta* Pease, 1868

## Range

Mozambique, Singapore, South Africa

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/invertebrate/molluscs/sap-sucking-slugs/green-lobiger)*
*Updated: August 30, 2026*