Chocolate arion vs Common corncockle

Arion rufus compared with Agrostemma githago

Key Differences

Chocolate arion is Vulnerable while Common corncockle is Critically Endangered.

Taxonomic Classification

Rank	Chocolate arion	Common corncockle
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Magnoliophyta (Flowering Plants)
Class	Gastropoda (Gastropoda)	Magnoliopsida (Dicots)
Order	Stylommatophora (Stylommatophora)	Caryophyllales (Caryophyllales)
Family	Arionidae	Caryophyllaceae
Genus	Arion	Agrostemma
Species	Arion rufus	Agrostemma githago

Conservation Status

Chocolate arion

VU — Vulnerable

Common corncockle

CR — Critically Endangered

Physical Characteristics

Attribute	Chocolate arion	Common corncockle
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 corncockle

Habitat

Found across multiple habitat types including montane grasslands and shrublands, tropical and subtropical moist broadleaf forests, and temperate coniferous forests, among 13 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Lesotho), Asia (7 countries), Europe (24 countries), North America (Canada, Mexico, United States), Oceania and the Pacific (Australia), and South America (Brazil, Chile). Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

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 corncockle

<em>Agrostemma githago</em>, commonly known as common corncockle, is an annual flowering plant in the family Caryophyllaceae. Once a widespread weed of cereal crops across Europe, Asia, and beyond, this species is now Critically Endangered on the IUCN Red List due to the dramatic decline caused by modern agricultural practices, particularly improved grain cleaning and herbicide use. Corncockle is a tall, slender plant covered in silky white hairs, bearing large, solitary pink to purple flowers with distinctive dark veining. Its seeds contain toxic saponin compounds called githagins, which historically contaminated grain supplies. The species now survives primarily in wildflower conservation areas, seed banks, and traditional farmland conservation schemes. It typically grows in open, disturbed arable soils with full sun exposure. Biological traits of this species remain poorly documented in the scientific literature.