Photo of the day (37): Helicopsis striata

Helicopsis striata is an interesting species. This land snail live in glacial loess steppe habitats. It lives on such habitats since ice ages. Steppes are fragmented and changed by people but this species can not live elsewhere. This means that it is a glacial relict.

It is extinct in France, it is critically endangered in Germany, in Austria, in the Czech Republic and in Slovakia. It is endangered in Poland. But it lives in large areas in Europe and it is considered as Least Concern species.

The width of the shell of this specimen is 7.5 mm and the height of the shell is 5 mm.

Helicopsis striataHelicopsis striata 02

Helicopsis striata 03

I have taken the previous three photos in the laboratory and the following photos in situ.

The steppe habitat – Čenkov steppe in Slovakia:
Helicopsis striata 04 habitat

A more closer look shows few shells of Helicopsis striata and another rare species – a plant Ephedra distachya in the top right:
Helicopsis striata 05 habitat

Helicopsis striata 06

Helicopsis striata 07

Helicopsis striata 08

Helicopsis striata 09

References

Species summary for Helicopsis striata. AnimalBase, last change 4 January 2014,accessed 29 October 2014.

Beran L., Juřičková L. & Horsák M. 2005: Mollusca (měkkýši), pp. 69-74. – In: Farkač J., Král D. & Škorpík M. [eds.], Červený seznam ohrožených druhů České republiky. Bezobratlí. Red list of threatened species in the Czech Republic. Invertebrates. – Agentura ochrany přírody a krajiny ČR, Praha, 760 pp.

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). pages 133-134.

von Proschwitz, T. & Neubert, E. 2013. Helicopsis striata. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 29 October 2014.

Stępczak K. Helicopsis striata (O.F. Müller, 1774). Polish Red Data Book of Animals, accessed 29 October 2014.

Trochulus hispidus crawling through water

I have taken few photos while a juvenile land snail Trochulus hispidus has been crawling through a very small water pool. Land snails are vulnerable to hyperhydration. But it has spent only about two minutes in the water. Maybe it did not affect its regulation of water much. Hydration is much less known in gastropods than dehydration. Maybe it did it for contact rehydration (“drinking” though the body wall) on that sunny summer day or maybe it has just overcome the pool because it just wanted to go that way. Nobody knows.

Trochulus_hispidus
Trochulus_hispidus_2
Trochulus_hispidus_3
Trochulus_hispidus_4
Trochulus_hispidus_5
Trochulus_hispidus_6
Trochulus_hispidus_7
Trochulus_hispidus_8
Trochulus_hispidus_9

I wish you happy and successful new year 2012. I wish you to overcome all difficulties and much more understanding from others.

 

References:
Barker G. M. (ed.) (2001) The biology of terrestrial molluscs. pages 159-163 and 467-468.

Mating of Xerolenta obvia

Xerolenta obvia is a hygromiid land snail. As its distribution area is referred Pontic region, but it occurs from Asia Minor to the Baltic Sea and to eastern France.

 

It lives in open dry grassy habitats. It is xerophilic (drought-resistant) and thermophilic species (lives in relatively high temperatures). This species hibernates in winter and it aestivates during summer for few months.

 

Aestivating Xerolenta obvia:

Xerolenta_obvia_aestivating

A group of aestivating Xerolenta obvia:

Xerolenta_obvia_aestivating_2

Epiphragm of Xerolenta obvia:

Xerolenta_obvia_epiphragm

It is a hermaphrodite land snail. It means, that one snail specimen has both sexes. Snails tranfer its sperm during mating. Later cross-fertilization occur. After some time later it lays separated 7-95 uncalcified eggs in a single clutch.

 

They reach sexual maturity in one year or later. For example in one area in Greece they reach maturity in 8 months after egg was layed (7 months after hatching), but they die after egg laying in the age about 1 year. In another area of Greece they reach sexual maturity in 1.5 years after egg was layed (= 18 months) and they have lived 2 years. Other source refer to longevity 2-3 years.

 

In Mediterranean they are mating and egg laying in autumn only. In Central Europe they are mating and egg laying from late spring to to early summer. It is mating in October (in Greece) after the aestivation in only few days.

 

I have found photos of mating of this species neither in the literature nor on the internet. I have taken 5 snails from the locality shown above to home at 3rd August 2011 and the later day I have recored the mating of them. Photos are in chronological order, but they are showing the same position all the time:

 

4th August 2011 06:25

Xerolenta_obvia_mating_1
Xerolenta_obvia_mating_2

6:29

Xerolenta_obvia_mating_3

6:32

Xerolenta_obvia_mating_4

Video of mating of Xerolenta obvia (30 seconds at 06:32):

06:39

Xerolenta_obvia_mating_5

06:40

Xerolenta_obvia_mating_6

Video of the last six minutes of mating:

References:

 

Irikov A. & Mollov I. (2006). Terrestrial gastropods (Mollusca: Gastropoda) of the western Rhodopes (Bulgaria). pp. 753-832. In: Beron P.: Biodiversity of Bulgaria. 3. Biodiversity of western Rhodopes (Bulgaria and Greece) I.

 

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

 

Lazaridou M. & Chatziioannou M. (2005). Differences in the life histories of Xerolenta obvia (Menke, 1828) (Hygromiidae) in a coastal and a mountainous area of northern Greece. Journal of Molluscan Studies 71(3): 247-252. doi:10.1093/mollus/eyi032 abstract

 

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

 

Species summary for Xerolenta obvia“. AnimalBase, last modified 22 March 2011, accessed 5 December 2011.

Photo of the day (7): Monacha cartusiana

Monacha cartusiana is hygromiid land snail of Atlantic-Mediterranean origin. It lives for example also in the southern England and in France. Is is considered as non-indigenous in (some parts of) the Central Europe, where it has isolated localities. It appears that it is spreading northward.

Monacha_cartusiana_01Monacha_cartusiana_02Monacha_cartusiana_03

Monacha cartusiana can be easily recognized according to the reddish margin of the lip and white lip. The shell is yellowish.

 

These photos are from Olomouc, Moravia, the Czech Republic.

It is usually sitting on vegetation like this:

Monacha_cartusiana_04Monacha_cartusiana_05Monacha_cartusiana_06Monacha_cartusiana_07

Juvenile specimen:

Monacha_cartusiana_08Monacha_cartusiana_09Monacha_cartusiana_10

Mapping project on BioLib.cz also includes Monacha cartusiana.

 

There are about 80 species in the genus. Up to 2011 there have been found only this one Monacha species in the Czech Republic. Another species Monacha cantiana has been recently found in Bohemia, the Czech Republic in 2009. We will see, if it will be also spreading, but its spreading is expected.

 

References:

 

Míkovcová A. & Juřičková L. (2008). “Hledá se tmavoretka bělavá. [The helicid snail wanted]”. Živa 2: 73.
http://ziva.avcr.cz/?c=1336 (Czech abstract), http://ziva.avcr.cz/?c=1336&lng=en (English abstract)

 

Pech P. & Pechová H. (2009). “Monacha cartusiana (Gastropoda: Hygromiidae) in South Bohemia”. Malacologica Bohemoslovaca <http://mollusca.sav.sk> 8: 28. http://mollusca.sav.sk/pdf/8/8.Pech.pdf

 

Novák J. & Novák M. (2009). “Dvě nové lokality tmavoretky bělavé Monacha cartusiana (O.F. Müller, 1774) na Moravě”. Malacologica Bohemoslovaca 8: 29-30. http://mollusca.sav.sk/pdf/8/8.Novak.pdf

 

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. http://mollusca.sav.sk/pdf/9/Suppl-1-v2.pdf

 

Hlaváč J. Č. & Peltanová A. (2010). “First occurrence of the Kentish Snail Monacha cantiana (Mollusca: Gastropoda: Hygromiidae) in the Czech Republic”. Malacologica Bohemoslovaca 9: 11-15.
http://mollusca.sav.sk/pdf/9/9.Hlavac-Peltanova.pdf

 

Peltanová A. & Novák J. (2011). “Map of distribution of Monacha cartusiana in the Czech Republic”. In: Zicha O. (ed.) Biological Library – BioLib. Retrieved on 2011-08-18. Available on: <http://www.biolib.cz/en/taxonmap/id191/>

 

Photo of the day (2): Monachoides incarnatus

Monachoides incarnatus is a very common hygromiid living in forests. Although it is very common, it does not go away from its forest to open land. It is easily recognizable for its reddish apertural margin and for example also for its typical microsculpture of shell (that is partly visible on the first photo).

 

I have taken this one to home and it is feeding on a piece of cucumber. It seems, that cucumber is the best food source for many snails. But I do not know, if it is only for large amount of water in cucumber (that may be more crucial in artificial conditions than in nature) or for the structure of this food or if it is somehow tasteful for snails.

 

Monachoides_incarnatus_2
Monachoides_incarnatus_3