Alien molluscs in British and Irish hothouses

Hothouse alien mollusc species, defined as those with breeding populations only able to live in heated environments, are under-recorded in Britain and Ireland. A project extending over 10 years visited 56 heated glasshouses and identified 15 such species, while another two are known to be present in British hothouses. One species, Liardetia samoensis, is new to the British list. Another 12 species which have previously been recorded as hothouse aliens are no longer extant in Britain or Ireland. Consideration is given to whether these aliens could lie in the open in our climate, and the consequences if they were able to do so. An Appendix lists all records of hothouse alien molluscs found in literature and on databases and will be a useful tool for future research.