Abstract
Since the time of the original description there have been no precise locality records in Cambodia of Bertia cambojiensis (Reeve, 1860) and it was believed to be extinct. In 2012, a joint Natural History Museum survey with Vietnamese colleagues rediscovered living populations of this huge sinistral helicoid snail in a protected area of southern Vietnam. The genitalia and radula morphology are re-assessed and type specimens of all recognised congeners are figured herein. The unique morphological characters of this species are a small and simple penis, well-developed amatorial organ complex that incorporates four amatorial organ ducts, a short gametolytic organ complex and spiked papilla, and radula morphology with unicuspid teeth. The type locality of B. cambojiensis, which has been contentious, is determined here to be in the vicinity of ‘Brelum’, Vietnam, near the border with Cambodia. In addition, the nucleotide sequences of barcoding genes COI, 16SrRNA and 28S fragments were provided for further comparison.
Highlights
The Dyakiidae Gude & Woodward, 1921, are a family of helicoid land snails restricted to Southeast Asia
Of the 12 recognised genera in this family, three are sinistral: Rhinocochlis Thiele, 1931, endemic to Borneo; Dyakia Godwin-Austen, 1891, comprised of about 20 nominal species distributed in the Greater Sunda Islands and Peninsular Malaysia, and Bertia Ancey, 1887, endemic to eastern Indochina with three recognised species (Zilch 1959, Hausdorf 1995, Schileyko 2003, Sutcharit et al 2012, Thach 2015)
We present new information on genitalia, anatomy and radula morphology of B. cambojiensis based on specimens in the NHM, London
Summary
The Dyakiidae Gude & Woodward, 1921, are a family of helicoid land snails restricted to Southeast Asia. Ancey (1887) described Bertia on the basis of the very large and sinistral, helicoid shell, initially as a monotypic genus based on Helix cambojiensis Reeve, 1860. On the basis of the reproductive anatomy of Helix brookei (Godwin-Austen 1891, Weigmann 1898, Laidlaw 1932), Baker (1941) subsequently placed Bertia within the family Trochomorphidae. Schileyko (2003) transferred Bertia to the Dyakiidae on the basis of characters of the genitalia and erected the new family Ryssotidae including Exrhysota as a distinct genus, which was subsequently synonymized with the Chronidae Thiele, 1931 by Bouchet et al (2017). Bertia cambojiensis (Reeve, 1860) was originally described under the name Helix mouhoti Reeve, 1860 [September], based on specimens collected by the famous French naturalist Henri Mouhot. Information on the type specimens of all recognised species in the genus are provided and the systematic position of “Helix brookei” is discussed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
