A mystery radula trail | The Conchological Society of Great Britain and Ireland

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Dear Mr.Topley,

I attach a picture taken in the fern House at Kew Gardens three weeks ago. I think it shows the foraging trail of a slug or snail, - the surface is a white-painted cast-iron column, coated with algae. The feeding mollusc has cleaned the paintwork very efficiently!

I am sure that your members should be able identify the species from the radula pattern (careful study reveals how the mollusc's feeding pattern is designed so that it ingests the maximum food, without foraging on previously cleared surface.) I think that the pic. shows an area approx.6" x 4".

I hope that the picture is of interest; you have my permission to use it in any way that you see fit.

Incidentally, I learned of your publication on 'Have I Got News For You' on television yesterday evening!

Yours Sincerely,
Peter Mason. 3rd December 2010

A comment from Roy Anderson:-

“The radula of non-marine molluscs is rarely examined nowadays....however... the shape and size of the marks left in the algae, could fit a large-ish slug species. I know there is a large population of Striosubulina and a few Gulella in the Palm House at Kew, but these are too small to be the mystery mollusc. My experience of hot-houses in Britain and Ireland, however, suggests the culprit might be Lehmannia valentiana This is no more than a guess, though.” - do members have any other ideas ? [Ed.]