The reproductive strategies of clausiliid land snails from Northern Vietnam (Gastropoda: Stylommatophora)

Abstract

Under laboratory conditions we scrutinized the reproduction and development of two clausiliid land snail species from northern Vietnam: Phaedusa paviei (Morlet, 1892) and Oospira vanbuensis (Bavay and Dautzenberg, 1899). These species, very similar in shell size and shape, feature different reproductive modes. The former is viviparous, giving birth to one or two neonates on a single occasion, with the number of developing embryos retained in the reproductive tract ranging from 1 to 11. The embryonic shells are 1.8–4.7 mm in height. The latter species is oviparous and produces eggs in clutches (four to six per clutch). Hatching occurs 18–21 days after egg-laying. Both species exhibit a similar growth pattern: the ultimate shell size is attained after 6.5–8.5 months and reproduction starts 5–7 months later. The distribution of viviparous reproduction among the Phaedusinae and its taxonomic importance are discussed.

KEYWORDS:

• Clausiliidae
• fecundity
• oviparity
• Phaedusinae
• phylogeny
• selfing
• southeast Asia
• viviparity

Acknowledgements

We are grateful to the anonymous reviewers for their comments on the earlier version of the manuscript, as well as to B.M. Pokryszko for correcting the English text. We are much obliged to Karolina Chaniecka and Ewa Janowska who participated in maintaining the culture and preparing the figures for this manuscript. Photographs were taken in the Laboratory of Microscopy Imaging & Specialist Biological Techniques at the Faculty of Biology and Environmental Protection, University of Łódź, created and equipped from the project no. POIS.13.01-009/12-00 (EU Structural Funds ‘Infrastructure & Environment’).

Authors’ contributions

AD contrinuted to study design, conduct of experiments, interpretation of data and writing of the manuscript; ACH contributed to conduct of experiments; and TM contributed to study design and interpretation of data.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Narodowe Centrum Nauki (2016/21/B/NZ8/03086).