The decollate snail (Rumina decollata) is a medium-sized predatory land snail, a species of terrestrial pulmonate gastropod mollusk in the family Achatinidae. It originated in the Mediterranean but has been introduced in a number of areas worldwide. It was recently found to represent a species complex.
Varieties Rumina decollata var. cruda Monterosato, 1892 Rumina decollata var. cylindrica Monterosato, 1892 Rumina decollata var. dentata Pallary, 1922 Rumina decollata var. fusca Pallary, 1899 Rumina decollata var. maura Crosse, 1873 Rumina decollata var. pellucida Monterosato, 1892 Rumina decollata var. solida Monterosato, 1892 Rumina decollata var. striatula Pallary, 1920
Distribution This species is native to the Mediterranean excluding south-east Mediterranean.
Over the last century its presence has been reported in China and found in large quantities.
It is introduced in Israel and in EgyptCommonwealth of Australia. 2002 (April) Citrus Imports from the Arab Republic of Egypt. A Review Under Existing Import Conditions for Citrus from Israel . Agriculture, Fisheries and Forestry, Australia. Caption: Gastropods, page 12 and Appendix 2. since Roman times. It has been introduced into North America, including Fresno, California, Phoenix & Glendale, Arizona and other areas as a biological control agent, in hopes of controlling populations of the brown garden snail. It has also been found in southern Brazil, and in Great Britain, as a "hothouse alien".
Shell description The shell of the decollate snail is long and roughly cone-shaped. It grows to approximately in length and a width of , and upon reaching mature size, grinds or chips off the end of its own shell by moving its body roughly against hard surfaces, so that the shell takes on a decollate shape, tapering to a blunt end.
Life habits
Sexual maturity occurs at approximately 10 months. An adult is capable of laying 500 eggs in its lifetime. The eggs are deposited singly in the soil and hatch within 10–45 days.
Rumina decollata is a voracious predator, and will readily feed upon common garden snails and slugs and their eggs. The snail eats plant matter as well, but this generalist predator is indiscriminate in its feeding and has been implicated in the decimation of native gastropods (including non-pest species) and beneficial annelids.
Decollate snails are tolerant of dry and cold conditions, during which they burrow deep into the soil. They are most active during the night and during rainfall.
References
Further reading
Herbert, D.G. (2010). The introduced terrestrial Mollusca of South Africa. SANBI Biodiversity Series, 15: vi + 108 pp. Pretoria. Mienis H. K. (2002). "Rumina paivae: the giant decollated snail from North Africa". Triton 5: 33–34. Crosse H. (1873). Diagnoses molluscorum novorum. Journal de Conchyliologie. 21(2): 136-144. Coquand H. (1862). Géologie et Paléontologie de la région sud de la Provence de Constantine. Mémoires de la Société d'Emulation de la Provence. 2: 5-342. Bieler, R. & Slapcinsky, J. (2000). A case study for the development of an island fauna: Recent terrestrial mollusks of Bermuda. Nemouria. 44: 1-99. Sparacio, I., Surdo, S., Viviano, R., Liberto, F. & Reitano, A. (2021). Land molluscs from the Isola delle Femmine Nature Reserve (north-western Sicily, Italy) (Gastropoda Architaenioglossa Pulmonata). Biodiversity Journal. 12 (3): 589–624 Johnson, C. W. (1900). Some notes on Rumina decollata Linn. The Nautilus. 13(10): 117. Smith, H. H. (1912). Rumina decollata in Mobile and New Orleans. The Nautilus. 26(1): 4-6 Ferriss, J. H. (1914). Rumina decollata in Texas. The Nautilus. 28(1): 11
External links
Rumina decollata on the UF / IFAS — Featured Creatures website. A photo of decollates feeding on Helix (ivy)