Chocolate arion vs Common Wall Cress

Arion rufus compared with Arabidopsis thaliana

Key Differences

• Chocolate arion is Vulnerable while Common Wall Cress is Least Concern.

Taxonomic Classification

Rank	Chocolate arion	Common Wall Cress
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Magnoliophyta (Flowering Plants)
Class	Gastropoda (Gastropoda)	Magnoliopsida (Dicots)
Order	Stylommatophora (Stylommatophora)	Brassicales (Brassicales)
Family	Arionidae	Brassicaceae
Genus	Arion	Arabidopsis
Species	Arion rufus	Arabidopsis thaliana

Conservation Status

Chocolate arion

VU — Vulnerable

Common Wall Cress

LC — Least Concern

Physical Characteristics

Attribute	Chocolate arion	Common Wall Cress
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

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.

Common Wall Cress

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Africa (South Africa), Asia (Japan, Taiwan), Europe (11 countries), North America (Canada, United States), Oceania and the Pacific (Australia), and South America (Brazil, Chile).

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.

Common Wall Cress

<em>Arabidopsis thaliana</em>, commonly known as common wall cress or thale cress, is a small annual flowering plant in the family Brassicaceae native to Eurasia and Africa, and now naturalized in North America, Australia, and other temperate regions worldwide. The species has become one of the most important model organisms in plant biology and genetics, owing to its small genome size, short generation time of approximately six weeks, prolific seed production, and ease of laboratory cultivation. <em>Arabidopsis thaliana</em> was the first plant to have its complete genome sequenced, in 2000, revolutionizing our understanding of plant molecular biology, development, and physiology. In nature, it typically grows in rocky outcrops, disturbed sandy soils, walls, roadsides, and waste ground, tolerating poor nutrient conditions and a wide range of climates. The plant produces a basal rosette of small ovate leaves, followed by an erect flowering stem bearing tiny white four-petaled flowers and slender silique seed pods. Despite its modest appearance, <em>Arabidopsis thaliana</em> has facilitated thousands of scientific discoveries in plant genetics, epigenetics, and stress responses. The species is currently assessed as Least Concern by the IUCN. Biological traits such as average lifespan, plant height up to 30 centimeters, and seed output are well-characterized in laboratory settings.

Shared Countries

Both species can be found in 6 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇫🇷 France 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States