Photo of the day (64): scalarid Helix pomatia

This is a deformed shell of a common Roman snail Helix pomatia. It is called scalarid shell. This deformation happens, when the mantle of the snail is damaged during the embryonic development. Therefore such shells are unobvious and rare. It is teratological specimen in general. “Teratological” means, that it has developed abnormally during its ontogeny – during the development of the individual.

Scalarid shell of Helix pomatiaI have never seen scalarid shell of Helix pomatia by naked eye before. I have taken this photo of shell in the Waldstein Riding School, Prague. It is a part of Cabinet of curiosities in the exhibition by František Skála.

References

Horsák M., Juřičková L. & Picka J. 2013: Měkkýši České a Slovenské republiky. Molluscs of the Czech and Slovak Republics. Kabourek, Zlín, 264 pp. (in Czech and English). page 142.

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Photo of the day (31): Helicigona lapicida

This photo is a four-eyed beast in a psychedelic green forest.
Helicigona lapicida 01
No, I was joking, these are two Helicigona lapicida snails on a lichen.

An apical view:
Helicigona lapicida 02

Another apical view:
Helicigona lapicida 03

The right side:
Helicigona lapicida 04

A top view:
Helicigona lapicida 05

A right side views:
Helicigona lapicida 06
Helicigona lapicida 07

Two snails on a rock:
Helicigona lapicida 08

Why it is on those stones on these photos? It is because inhabits rocks and walls. It is quite common snail already described by Carl Linnaues in 1758. Linnaues used the specific name lapicida for this snail, because he thought that its mucus can dissolve limestone rocks. The Latin word lapis means the “stone”, the Latin suffix -cida means “cut out”. The Latin word lapicida means the “stonecutter”. It can not dissolve stones in fact.

The foot:
Helicigona lapicida 09

The umbilical view:
Helicigona lapicida 10

Six Helicigona lapicida snails in situ in Kamenice castle on the Zámecký vrch hill in Česká Kamenice town (Northern Bohemia, Czech Republic.)
Helicigona lapicida 11

What does it eat on those rocks? Lichens. Like this one:
Helicigona lapicida 12

References:

(in Czech) Blažka F. (1892). Na venkově po dešti. Vesmír, 22(3): 5-6.

Lapicide. Wictionary, accessed September 12, 2014.

Etymology of the Latin word lapicida. myEtymology, accessed September 12, 2014.

Climbing competition: gecko vs. snail

Gecko and a snail are disputing who is better at climbing.

Gecko:   I can walk on the wall.
Snail:      Me too.

Snail on a grey wall

Helix pomatia is crawling on the wall.

Gecko:   I can walk on the ceiling.
Snail:      Me too.
Gecko:   I can walk on the glass wall.

Phelsuma v-nigra comoraegrandensis on the plastic. Photo by Petr Bogush, CC-BY-3.0

Phelsuma v-nigra comoraegrandensis on the plastic. Photo by Petr Bogush, CC-BY-3.0

Phelsuma inexpectata on the glass. Photo by Petr Bogush, CC-BY-3.0

Phelsuma inexpectata on the glass. Photo by Petr Bogush, CC-BY-3.0

Snail:      Me too. Moreover I can crawl over razor blades.
Gecko:   OK. Show it. You will cut yourself and I will be the only climber. Ha ha.

Helix pomatia next to razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade Helix pomatia on a razor blade

Snail:      It was easy.
Gecko:   Wow! Very impressive! But we are not talking about razor blades. Hey snail, you are good, but I am faster. You have to admit that I AM the best climber and I can climb everywhere.
Snail:      No, you are not. I have seen your video on YouTube.
Gecko:   Which one?
Snail:      THIS one. You failed. And this one:

Gecko:   That is an only exception. It is polytetrafluoroethylene, commonly known as teflon. It is the only material that geckos can not crawl. But at least I tried that.
Snail:      I can crawl it.
Gecko:   Ha-ha-ha-ha-haaaaaaaaaaa!!! Don’t you know that? Nobody can crawl on teflon. It has non-stick surface so nobody can stick to it. Teflon has very low surface tension. Teflon consist of atoms of carbon and atoms of fluorine. Electrons of fluorine are very tightly bounded. Therefore there are very weak van der Waals forces. Unfortunately these forces allows me to crawl on any material except of teflon.
Snail:      I can really crawl it.
Gecko:   If you think so. Try to crawl on this frying pan that has a teflon non-stick coating, But be careful. Some people say that teflon is not safe.
Snail:      Do not worry. It is hazardous only in temperatures above 200 °C.
Helix pomatia on teflon Helix pomatia on teflon Helix pomatia on teflon Helix pomatia on teflon

Where else should I climb to?

Where else should I climb to?

Gecko:   OK. You won. But tell me, how do you do that?
Snail:      First of all, I attach the whole foot to the surface all the time. Second, I create mucous layer that allows me to adhere to nearly any material. This is called adhesive locomotion. It cost me much energy, much water resources and it is slow, but it is one of the most effective method among all animals.
Gecko:   Nearly. You said “nearly”! Finally!!! There exist something that you can not climb to. What is it?
Snail:      Ummm… Well… Yes. There exist some snail resistant materials. For example I can not climb to radomes when they are painted with a superhydrophobic paint Hirec 1440. It is because radomes are weatherproof and they protects antennas from freezing rain.

A radome. Photo by U.S. Department of the Interior, National Park Service, Historic American Engineering Record.

A radome is a ball-like protectin of an antenna. Photo by U.S. Department of the Interior, National Park Service, Historic American Engineering Record. Public domain.

References:

Shirtcliffe N. J., McHale G. & Newton M. I. 2012: Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces. PLoS ONE 7(5): e36983. doi:10.1371/journal.pone.0036983

Wikipedia contributors. Teflon. – Wikipedia. accessed 25 May 2013

Photo of the day (24): Causa holosericea

Causa holosericea (Studer, 1820) is a land snail from the family Helicidae. It has Alpine distribution.

It lives mainly in humid mixed forests and in coniferous forests, but also in decidous forests. It can be usually found under the fallen timber.

Causa_holosericea
Causa_holosericea_2

There are fine hairs on the periostracum that gives velvety feels to the shell. Some vernacular names are based on these velvety hairs.

The Czech name of Causa holosericea is aksamítka sametová.

Czech etymology:
aksamit = silk velvet,
aksamítka (from dialect from Moravian Wallachia) = velvety ribbon or low fur hat with velvety surface and with edging made of fur from an otter (this fur hat is also called vydrovka in Czech),
sametová = velvety.

 

The Slovak name of Causa holosericea is aksamietka zamatová.

Slovak etymology:
aksamit = silk velvet,
aksamietka (colloquial expression) = velvety ribbon,
zamatová = velvety.

 

This post is devoted to the Velvet Revolution, that started on 17th November 1989 at that time in Czechoslovakia.

 

References:

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

(in Czech) Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. 2010: Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. [Annotated list of mollusc species recorded outdoors in the Czech and Slovak Republics]. – Malacologica Bohemoslovaca, Suppl. 1: 1-37.

(in Slovak) Lisický M. J. (1991). Mollusca Slovenska [The Slovak molluscs]. VEDA vydavateľstvo Slovenskej akadémie vied, Bratislava, 344 pp., page 322.

(in Slovak) Országh I., Čejka T. & Országhová Z. 2012: Slovenské mená mäkkýšov (Mollusca). [Slovak Names of the Mollusca]. – Univerzita Komenského v Bratislave, 208 pp., ISBN 978-80-223-3170-8.

(in Slovak) “aksamiet” – význam slova. slovnik.sk, accessed 17 November 2012.

(in Czech) Slovník spisovné valaštiny. accessed 17 November 2012.