5 x Unicorn Snail, Octona Subulina

The Unicorn snail – Subulina octona, a small snail native to the tropical Americas, is now widespread across the globe, including the Caribbean, Hawaiian Islands, Africa, Asia, Australia, West Indies, Sri Lanka, and Pacific Islands. Additionally, it has established populations in Tanzania, Dominica, Czech Republic (as a “hothouse alien”), Great Britain (also as a “hothouse alien”), Pratas Islands in Taiwan, and other regions.

Unicorn snails are highly social and are typically found in large numbers in damp, shaded areas among stones, grass, moss, leaf litter, and other debris. They can be harmful to agricultural plants, such as orchids.

They can Measure up to 1.3 inches (3.3 cm) in length and their average shell size ranges from 0.6 to 0.8 inches (1.5 to 2 cm). The shell is elongated, smooth, and glossy, with up to 8-9 rounded whorls and deep sutures. It appears translucent yellowish to brownish, with dark apical whorls in adults. The body is pale yellow and can stretch to the shell’s length.

Under optimal conditions, Subulina octona Unicorn snail can live up to four years, though the average lifespan is around 2.5 years. These non-aggressive, docile, nocturnal snails may bury or hide during the day to avoid predators. They thrive in groups and are herbivores and detritivores, feeding on vascular plant material, lichens, fungi, and soil. In captivity, they enjoy fresh lettuce leaves, vegetables like carrot, courgette, cucumber, chayote, sprouts, green beans, and spinach. Their diet should include calcium sources like cuttlebones, eggshells, natural chalk, oyster shells, kale, and broccoli to prevent shell deterioration.

For housing, plastic containers with proper ventilation are ideal. A 1-gallon (4-liter) tank can house 10 or more snails. Use coconut fibre, soil, and peat as substrate, avoiding stones and gravel to prevent shell damage. These snails prefer a warm, humid environment with temperatures between 24-27°C (75-80°F). While they can survive in cooler temperatures (20-22°C or 68-72°F), they will be less active. Maintaining 80% or higher humidity is crucial for their respiration.

Subulina octona does not need an additional water source, obtaining sufficient moisture from the soil and food. They appreciate leaves, wood, plants, and other decorations, particularly enjoying moss and wooden sticks for rasping and eating tree bark.

Unicorn snails are hermaphroditic, possessing both male and female reproductive organs. They reproduce through internal self-fertilisation, laying eggs with well-developed embryos. Eggs, visible through the transparent shell, are retained until a few days before hatching and then buried in the soil. Each reproductive event yields 4-5 eggs, with an average of 124 eggs over 18-33 events during their lifetime.

All in all unicorn snails can make fascinating pets and they can cohabit with a variety of other minibeasts such as isopods, milllipedes etc as the basis for a beautiful bioactive terrarium.