Description of the second Calybium Morlet, 1892, and the first record of the genus for Vietnam’s terrestrial gastropod fauna (Neritimorpha: Helicinoidea: Helicinidae)

Researchers have identified and described Calybium plicatus, a new species of terrestrial gastropod (snail) belonging to the genus Calybium. This discovery marks the first record of the genus in Vietnam's terrestrial fauna, specifically within Phong Nha-Ke Bang National Park and Hin Nam No National Park, part of UNESCO World Heritage Sites. The species was collected from Son Doong Cave in Quang Binh Province, Central Vietnam. Unlike its congener, Calybium massiei, C. plicatus exhibits a smaller shell size and distinct parietal wall features with six evenly spaced lamellae. This finding contributes to the understanding of biodiversity within these protected areas and expands the known distribution of the genus.

HOANG, N. K., VU, V. L., TRAN, T. T. B., NGUYEN, T. S., & DO, D. S. (2025). Description of the second Calybium Morlet, 1892, and the first record of the genus for Vietnam’s terrestrial gastropod fauna (Neritimorpha: Helicinoidea: Helicinidae). Ruthenica, Russian Malacological Journal, 35(1), 39–45. https://doi.org/10.35885/ruthenica.2025.35(1).4