How to (not) transport Eucobresia diaphana

(This post was released on 28th October 2011 and I have changed one of its photos and some  texts on 9th December 2011.)

Eucobresia diaphana is a semi-slug with Alpine-central European distribution that occur in wet cold places.

My specimen comes from Hrubý Jeseník Mountains, the Czech Republic, from altitude 764 m above sea level. In the surrounding Poland it lives only in Lower Silesia.

This semi-slug can not withdraw into its very small shell. According to Falkner et al. (2001) it will survive desiccation of its habitat for hours or for days only. This land semi-slug is even less adapted for drought than some freshwater snails. For example freshwater snail Planorbis planorbis will survive desiccation of its habitat for weeks or months.

Eucobresia diaphana requires wet environment always. I have highly underestimated this requirements. I have placed the semi-slug to dry paper box. Eucobresia diaphana did not survive transport in such conditions in less than two hours. The semi-slug was completelly dried in less than two hours and it was fixed to the box, so when I have tried to take it, the dried body has broken! I had to use at least moist paper box when I had no other box.

The photo of dead Eucobresia diaphana placed in water with its tail removed. The mantle normally cover the whole apex in live Eucobresia diaphana, but here is the apex visible on this dead specimen:


This embarrassing example shows, how some gastropods are very sensitive to environmental conditions.

The photo of the shell is from the same specimen. Apical view of the shell:


Umbilical view of the shell:


The umbilical view of the shell enables view of apex because columella is curved in such way, that all preceeding whorls are visible. Such shells are called “strofostylní” in the Czech language.

I have taken these photos of the fresh shell in water to show the shell undamaged including undamaged apertural membrane. You can compare these photos with photos of dried shells at AnimalBase.

I have taken these photos of translucent shell on white background (white paper). There were not seen much details on the shell in direct light, so I made these photos in a shadow with reflected light. A little bit red color on the second photo is a shadow or the light, that moved through my own hand (I have used very strong light source).


Falkner G., Obrdlík P., Castella E. & Speight M. C. D. (2001). Shelled Gastropoda of Western Europe. München: Friedrich-Held-Gesellschaft, 267 pp.

Pokryszko B. M. & Maltz T. K. (2007). Rare and endangered terrestrial gastropods of Lower Silesia (SW. Poland) – current status and perspectives. Acta Universitatis Latviensis 723: 7-20.

How does Oxychilus draparnaudi eat

Finally I have taken some photos of Oxychilus draparnaudi feeding on Trochulus hispidus after two months and half of keeping it.

I have taken the first photo on 15 October 10:34 AM and it stopped feeding on 10:52 AM. Although it is referred as a nocturnal animal, I was glad to see it feeding on daylight. It was sunny day, so taking photos was not difficult.

The first photo shows the foot, because it was feeding on the transparent lid of the terrarium. The predator was holding the whole of its prey when it was upside down.


Then I have removed the lid and rotated the lid to take these photos:


First photos immeditelly after the feeding:


Usually after the feeding process are shells empty and clean. I have probably distrubed its feeding process, because it seems that it have eaten the body of the first 3/4 of the first whorl only. The same shell of Trochulus hispidus still contain some material inside:


Open data:

continuously updated spreadsheet with data what Oxychilus draparnaudi have eaten.


Photo of the day (11): Perpolita hammonis

Perpolita hammonis is a small land snail. It is also known as Nesovitrea hammonis. It lives in Palearctic. It is quite common species, that lives in forests as well as in open habitats. Although it belongs to Oxychilidae, it can be easily identified, because it has regular radial ribs on the shell that are clearly visible under any magnifying glass.


It prefer from moist to wet humidity, so I keep them rather in wet environment.



Falkner G., Obrdlík P., Castella E. & Speight M. C. D. (2001). Shelled Gastropoda of Western Europe. München: Friedrich-Held-Gesellschaft, 267 pp.

(in Slovak) Lisický M. J. (1991). Mollusca Slovenska [The Slovak molluscs]. VEDA vydavateľstvo Slovenskej akadémie vied, Bratislava, 344 pp.