'Rockers' and 'Wallers'

by Helmut Nisters, Innsbruck, Austria


The smaller landshells that live on walls or in rocky habitats are very attractive. This article provides guidelines on where to find them and is illustrated with a variety of species.

When you see a collection of inland shells, you might ask yourself where you could find them. Landshells really do exist nearly everywhere. They can be found next to your own home and houses, in farms and gardens, under bushes (Fruticicola fruticum (Fam. Bradybaenidae), Arianta arbustorum (Fam. Helicidae), Cepaea hortensis and Cepaea nemoralis (Fam. Helicidae)), as well as in dry habitats, such as on slopes, that are dry or exposed to the sun with grass or rubble (Zebrina detrita (Fam. Buliminidae), Chondrula tridens, Jaminia quadridens (Fam. Buliminidae), Candidula unifasciata , Xerolenta obvia obvia (Fam. Hygromiidae)).

 



Fruticicola fruticum
20mm


Zebrina detrita
20mm


Chondrula tridens tridens
6mm

 
Jaminia quadridens
10mm



Candidula unifasciata
6.5mm



Xeolenta obvia obvia
12.5mm

 

They may also be discovered in shadow and quite humid places with many possibilities for concealment, in forests with rocks and rocky steps covered with leaves and mould (a few species of Buliminidae, such as Ena montana, Merdigera obscura and some species of Clausiliidae), of which deciduous and mixed forests are the more preferable. Forests in fertile plains are a quite suitable place for other species (alder and beech). A few landshells are living in the surroundings next to water biotopes, as in reed (Zonitoides nitidus (Fam. Gastrodontidae), Succinea putris, Oxyloma elegans (Fam. Succineidae)).

Some enjoy old wood and roots, under and between stones (a few species of Fam. Clausiliidae or Helicodonta obvoluta (Fam. Hygromiidae), Isognomostoma isognomostomos (Fam. Helicidae)). You can find some species at remarkable altitudes in the mountains, even above the timber-line on alpine pasture grounds under stones (Vertigo arctica (Fam. Vertiginidae), Eucobresia nivalis, Gallandia annularis (Fam. Vitrinidae)).


Helicodonta obvoluta
11mm


Isognomostoma isognomostomos
9mm


Eucobresia nivalis
5.5mm

Larger species you can collect easily by hand or using tweezers, under bushes, or by turning barks, old wooden boards and planks, stones, but you should remember to put displaced objects back in their original position without destroying the habitat. The smaller species and micro-shells you can find by sieving the material as I've recently explained in the article on the shells of the Castle of Ambras. Among the best environments are certainly areas with calcareous rocks and stones: as the "house-builders" among the landshells prefer habitats, rich in calcium. Rocks often have a very rough (rugged) surface with many fissures and so offer a lot of suitable hiding places for many of our landshells.

In the Alps, and especially in the Tyrol, we can find a quite good number of such idoneous places, such as localities with shady gorges and rocks, but also some sun-exposed ones, as the different shells like different habitats. The rockers of the inland shells, I mean those species living on rocks and in (calcareous) rubble, are less pretentious in their frugal existence and feed only on the plants which they can find in the nearest surroundings, such as moss and lichen.

Especially after rain you can find many of these species, when they are climbing on the rocks and on vegetation which is growing from fissures. You need quite a good eye too, if you want to find the smaller species like Pyramidula pusilla. But you can find them as they are quite gregarious. In the South-Tyrol or Alto Adige and Trentino (Northern Italy) you can find many natural dry stone walls, which replaces as a secondary biotope, the rocks that many species thrive on. But these walls will get more and more cemented and so living space of many landshells or other animals will become endangered.

The rockers and wallers mostly belong to the families of Cochlostomatidae, Pyramidulidae, Chondrinidae, Helicidae and here particularly the Genus of Chilostoma, Helicigona and the southern Genus Marmorana. Rockers and Wallers are land-shells that are able to exist in a wide range of environments and climates by various forms of adaptation.

Investigating the huge variety of sites listed in the article will no doubt be rewarding for those naturalists with an eye for a new challenge or just add to the enjoyment of the exploration of the wild.

Comments to the author Helmut Nisters are welcomed. Other contact details in Appendix.

 

Images of a variety of land-shells, arranged by habitat.

(In systematic order. The size given is the length or diameter of a typical specimen.)

Group A ('rockers' and 'wallers'): pure rocks with fissures, rocky steps and rubble.


Cochlostoma henricae henricae
9mm



Pyramidula pusilla
2.5mm


Granaria illyrica
8.5mm


Abida secale secale
7.3mm


Chondrina avenacea avenacea
7mm


Chondrina arcadica clienta
6mm


Chondrina multidentata gredleriana
6.5mm


Lauria cylindracea
3.7mm


Charpentieria itala braunii
18mm


Charpentieria stenzii cincta
15.5mm


Charpentieria stenzii letochana
15mm



Erjavecia bergeri
11mm


Clausilia rugosa parvula
8.5mm


Neostyriaca corynodes corynodes
9mm


Balea perversa
8mm


Helicigona lapicida
16mm



Chilostoma cingulatum peregrini n. nom.
23mm



Chilostoma cingulatum baldense
25mm


Chilostoma achates achates
23mm


Cepaea nemoralis nemoralis
23mm

 

 

Group B: Typically in more open habitats to forests of different density with rocks, rocky groups, under old wood, under and between stones, in leaf mould.


Acicula lineata
3.75mm


Truncatellina monodon
2.3mm


Orcula dolium dolium
7mm



Orcula gularis
6.5mm



Pupilla triplicata
2.75mm


Merdigera obscura
8.5mm


Cochlodina orthostoma
11.5mm



Vitrea crystallina
2.5mm


Petasina unidentata
7.5mm

 

Appendix

Helmut Nisters contact details (work and home).

Natural History Department of the Tiroler Landesmuseum Ferdinandeum Innsbruck,
Malacological Collection,
Feldstr. 11a,
A-6020 Innsbruck, Austria, Europe.
Phone: 0043 512 58 72 86 37.
Helmut Nisters
Franz-Fischer-Str. 46
A-6020 Innsbruck, Austria, Europe
Phone and Fax: 0043 512 57 32 14
E-mail:
www.helix@ibk.netwing.at
URL:
www.netwing.at/nisters/

Digital image capture details: Images taken by David Walker of shells supplied and identified by Helmut Nisters. Smaller shell images taken with Panasonic CL350 video camera with 50mm Nikon SLR lens and extension tubes. Largest shells taken with Fuji DX-10 digital camera in 10cm macro mode.

 

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Published in the August 1999 edition of Micscape Magazine.

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