30 July 2012

Gastropod anatomy from photographs of live animals

One can learn much about gastropod anatomy by watching live animals and studying their photographs. In fact, there are certain aspects of gastropod anatomy that are hard to appreciate in preserved specimens. Some examples with nice photos are in this article of mine that recently was published in Mollusk World, the magazine of the Conchological Society of Great Britain and Ireland. A pdf copy is available here.

16 July 2012

Discus rotundatus in Montreal


In August 2008, I announced here my finding of the snail Discus catskillensis on Mont Royal in Montreal, Canada*. Subsequently, a few readers questioned my identification and suggested that the snail I had found was more likely the European species D. rotundatus. While the former species is a native of North America, the latter was introduced to the eastern U.S. early in the 20th century and later to Canada.

For a more definite identification, I needed more specimens. But I did not have a chance to go back to Mont Royal until August 2011 when I was able to collect a few more shells. Last fall, I compared the Montreal specimens with the shells of several Discus species. The results indicated that the Montreal species was indeed D. rotundatus.

The final outcome of this project was a short paper that recently got published in Check List. You may download a copy of it from here.

*I have now deleted the original post of 2008. Attempting to revise it would have been too much trouble.