Acusta redfieldi — identification & habitat

Acusta redfieldi is the everyday garden snail of South Korea, and it is also widespread in central and southern China. For years Korean snails were lumped with a Japanese relative, but DNA studies show they belong to this mainland species. It has no common English name, and no wild populations are known in the United States.

Appearance

Appearance: A round shell about 0.8–1.2 in (2–3 cm) across. Most are pale ocher with brown markings, but some individuals are much darker, almost black. The eyes and are black.

Where it lives

Typical habitats: Gardens
Grassy thickets
Low hillside trails
Farm fields
Range: East Asia: central and southern China and South Korea, including islands such as Jeju and Ulleungdo. No wild populations are known in the United States.
Preferred conditions: Likes damp places and comes out in numbers on rainy days, climbing walls and plants.

Behavior

Diet: Mostly chews plant leaves and also eats dead insects. In Korea it has damaged ginseng fields mulched with rice straw.
Activity: Most active in wet weather. In heat or drought it seals its shell opening with a thin film to hold in moisture, and in Korea it hibernates from about November to April.

Life cycle

Reproduction: Each snail is both male and female; during mating two snails swap sperm. Eggs are laid in moist soil.
Clutch size: About 28 eggs per clutch on average
Incubation: Eggs are white, round, and about 0.08 in (2 mm) wide; in the lab they hatched in about 12 days.
Lifespan: The life cycle takes about one year in the wild; kept snails live 1–2 years.

Name and classification

About the name: Korean populations were long called Acusta despecta sieboldiana, the name used for a Japanese snail. A 2023 DNA study placed them with Acusta redfieldi from China instead. A. redfieldi itself was once treated as a subspecies of Acusta ravida.