Greek Terrestrial Mystery

Data: I hope you will be able to help me identify the snail featured in the attached picture.

I saw many of these snails on a recent trip (July) to the Greek island of Syros in the Cylades group. The snails were found exclusively on any object raised from the ground - tall stalks of study grasses, fence posts and telegraph poles. They seemed to be found mainly in large collections as shown and were attached fast to there chosed site with a hard, glossy cement like substance.

I would be interested if you could enlighten me on their name and more interestingly thier habit of attaching themselves to raised vertical structures. I have speculated that this habit may be a means of surviving hot dry conditions of the summer months, but am still astounded at the duration and heat of their “hibernation” if this is trre as they did not appear to prefer shaded spots to full sun at all.

I look forward to hearing from you or from another interested party if you post my picture on your website.

Many thanks

Simon Rose

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  • These are either Cepaea hortensis or Cepaea nemroalis snails. Both snails are found on the Greek Islands.
    The mucous plug (epiphragm) serves to hold in fluids while the snail hibernates. It also acts like a glue to connect them to structures. They most likely climb up trees and other structures to escape enemies while they are hibernating and I would imagine it is cooler as well. Snails must do everything they can to keep in their precious fluids. To dry out is to die! ...Avril B.

  • It is NO Cepaea surely. ...Lubosh

  • Surely it's not a Cepaea. Maybe Theba ¿pisana? as more usual species, but also possibilities for Codringtoni a sp. or any Hygromiidae. ...Javier

  • This is not a Cepaea, this is a Theba pisana. Best regards, ...Holger

  • It belongs to Helicellidae. This family contains several genera which are extremely difficult to tell apart using shell-characters. However the species in question is likely to be Trochoidea cretica (Férussac 1822). It is likely that other helicellids have been introduced there also.
    Helicoids estivate during especially hot dry weather; they position the aperture closely against a solid substrate and seal the gaps up with mucus, which dries. Some members of the related family Helicidae can survive for up to 5 years or so in this fashion. ...Andrew

  • They are 100 % Theba pisana to me. They are abundant in south coast of Turkey also. ...ümit

  • I agree -Definitely looks like Theba pisana -Typical habits and habitat.
    Quite common here in southern Australia introduced along parts of the coast. ...Geoff

  • Most probably the species is Theba pisana. The colour pattern of Trochoidea cretica (belongs to the Hygromiidae!) is different. Pisana is widespread in the whole mediterrenean area ...Wim

  • It also has tramped to the United States. According to Dundee (1974: 31), it has not become established, but Pilsbry (1939: 13-14; fig. 7) showed convincing evidence that it had become naturalized in San Diego, Orange and Los Angeles Cos., California.
    Dundee listed 19 countries of origin and ports in 19 different states at which it had been intercepted!
    I haven't seen or heard of it in Florida (yet).
    It is named for Pisa, Italy, part of its natural range. ...Harry ...........
    Dundee, D., S., 1974. Catalog of introduced mollusks of eastern North America (north of Mexico). Sterkiana 55: 1-37. Sept.

  • Related to Harry's comments: Considerable effort was made to eradicate this agricultural pest in California. To my knowledge, it was all but eliminated except for small colonies here or there (I know of one such colony in Santee, inland San Diego County where it is found with Otala lactea, Helix aperta, Rumina decollata, Cernuella virgata and Vallonia pulchella, all introduced). ...Phil

  • >Most probably the species is Theba pisana. The colourpattern of Trochoidea cretica (belongs to the Hygromiidae!) is different. Pisana is widespread in the whole mediterrenean area.
    How DARE you people be right??
    As I said, these beasties are difficult to identify.
    According to Vaught and Abbott 1989 Trochoidea is in Helicellidae.
    It might be of interest to some to hear that Candidula intersecta is alive & well around limestone cliffs in New Zealand. They can be extremely common after rain, even crawling across the bottoms of very small pools, but when it's dry there will be not a sign of any living specimen. ...--Andrew

  • Andrew - Candidula intersecta is also common here in Melbourne in coastal areas and as you say is well hidden most of the tome ...Geoff

  • I have found some in the Palos Verdes Peninsula area of Los Angeles. ...Jack

  • First, Xerocrasa cretica (not Trochoidea anymore) is a rather restricted invasive (Mediterranean only) and does show so much polymorphism in the outside range (totally white or few faint bands).
    Second, rather correct way to put it was saying the pattern is totally of pisana. Besides no Helicellinae (-dae) (Hygromiidae is the correct term here) is globular in shape.
    Candidula observation is interesting. But note that even coastal, it is not a Mediterranean species but an Atlantic one. Indeed, i doubt if they can survive summers Theba do and if they get such long dry seasons. Like Cernuella and Cochlicellas Theba is a dune dweller on the other hand...
    Don't have an idea? Then ask Mediterranean snailers :) ...Ümit :)

  • Hi Simon, I observed exactly the same behavior that you described in the S. of France in June, 2007. The snails were on most of the grass stems, on weeds, on grape vines and they were always above ground level and stuck tight. I identified them as Theba pisana which agrees with the majority on Conch-L. They match your photo. Bert

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