Chocolate arion vs Fly Agaric

Arion rufus compared with Amanita muscaria

Key Differences

Chocolate arion is Vulnerable while Fly Agaric is Least Concern.

Taxonomic Classification

Rank	Chocolate arion	Fly Agaric
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Mollusca (Mollusks)	Basidiomycota (Club Fungi)
Class	Gastropoda (Gastropoda)	Agaricomycetes (Mushrooms)
Order	Stylommatophora (Stylommatophora)	Agaricales (Gilled Mushrooms)
Family	Arionidae	Agaricaceae (Agarics)
Genus	Arion	Amanita (Amanitas)
Species	Arion rufus	Amanita muscaria

Conservation Status

Chocolate arion

VU — Vulnerable

Fly Agaric

LC — Least Concern

Trend: Stable →

Physical Characteristics

Attribute	Chocolate arion	Fly Agaric
Diet	—	Decomposer
Average Lifespan	—	1 years
Average Length	—	20 cm
Average Weight	—	100 g

Habitat & Geographic Range

Chocolate arion

Habitat

Inhabits temperate broadleaf and mixed forests and Mediterranean forests and woodlands within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found across Europe (7 countries) and North America (United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Fly Agaric

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Widely distributed across Europe (4 countries), North America (United States), Oceania and the Pacific (New Zealand), and South America (Brazil, Chile, Colombia).

Chocolate arion

The Chocolate Arion (Arion rufus), also known as the Large Red Slug or Chocolate Slug, is one of Europe's largest terrestrial slugs, with adults reaching up to 15 centimetres in length. It belongs to the family Arionidae within the phylum Mollusca, and despite its common name, adults display highly variable colouration ranging from reddish-orange to dark brown and nearly black — only certain colour morphs exhibit the chocolate-brown hue that partly inspired the name. Arion rufus is native to western and central Europe, where it inhabits woodland, hedgerows, gardens, agricultural land, and other moist habitats. It is also established as an introduced species in parts of North America. Like other arionid slugs, it is primarily a detritivore and herbivore, consuming dead plant material, fungi, living plant tissue, and sometimes carrion. It shelters under logs, stones, and leaf litter during dry or cold conditions, becoming active — particularly at night — during warm, moist weather. Chocolate arion can cause significant damage to gardens and crops. Reproduction is hermaphroditic; slugs exchange sperm and lay batches of translucent eggs in soil or under debris. The IUCN classifies this species as Vulnerable, reflecting pressures on native European populations from habitat change and, possibly, competition and hybridisation with related Arion species.

Fly Agaric

Among the most iconic and recognizable fungi on Earth, fly agaric mushrooms display striking red caps with white flecked warts across boreal forests of the Northern Hemisphere. Despite their fairy-tale appearance, they contain potent psychoactive compounds including muscimol and ibotenic acid and are moderately toxic. They form critical mycorrhizal symbioses with birch, pine, and spruce trees, exchanging mineral nutrients for carbon and playing essential roles in boreal forest nutrient cycling.