A new species of Sesara Albers, 1860 from northeastern Thailand (Stylommatophora: Helicarionidae)

ABSTRACT

Sesara triodon n.sp. is described from the Phu Pha Lom limestone area in Loei, northeastern Thailand. It possesses a small and depressed–conoid, transparent shell with a shiny external surface. The aperture possesses three apertural teeth, in contrast to other Thai species, Sesara parva Solem, 1966 (two teeth) and Sesara megalodon Blanford, 1902 (four teeth). The genital system of the new species has some distinctive characters, including a vagina longer than the free oviduct, and the epiphallic retractor caecum is rounded and bulbous. The radula has 104 rather straight rows of teeth, with each row having74–81 teeth. This is the easternmost record of the genus Sesara in Thailand.

http://zoobank.org/urn:lsid:zoobank.org:pub:52EF0AB6-1E17-4B96-BC6F-4257FE5FBF00

KEYWORDS:

• Epiphallic retractor caecum
• Gastropoda
• Loei Province
• radula morphology
• reproductive anatomy
• spermatophore
• taxonomy

Acknowledgements

We would like to thank Mr Sophon Thip-Apakul and all the staff from Phu Pha Lom Forest Park, Loei Province, for their help in making our fieldwork possible. We thank Miss Nualanong Narkkong and the staff from the SEM laboratory, Faculty of Science, Mahasarakham University, for their help with sample processing and SEM work, and Mr Jirayut Wiang-In for taking the photographs of this material. We are very grateful to everybody who assisted with the land snail collection. Special thanks to Dr Jolyon Dodgson for kindly checking the manuscript. We thank reviewers, Dr Winston Ponder and Dr Isabel Hyman for their valuable comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was financially supported from the annual government statement Year 2013 of Mahasarakham University (5605002/2556) and by Mahasarakham University 2014 (5703003/2557).