Monday, January 28, 2013

Shotesham snail woe continues

Well, two more species confirmed - Velvet Shank Flammulina velutipes and the micro-moth Agonopterix arenella bring me to 158. The moth was in the house - despite putting the trap on last night, I had no success there, nor in my two little pitfall traps I set up yesterday. Hope springs eternal...

Still puzzling over my snails though. Here's two of them, top and bottom, both removed from the walls of the house in a rural garden:

Snail 1 - 10mm wide, 7 mm high - 5+ whorls, large umbilicus, no obvious lip, not keeled. Dark, blotchiness showing through towards centre particularly. I don't think I'd call this glossy, waxy or particularly translucent? But if I follow the key for the Helicoidea, I end up at (a small) Trochulus striolatus, which I think has a lip. If it is glossy, then perhaps this is Oxychilus cellarius? But it doesn't really look glossy enough?




Snail 2 might be the same thing but paler. I don't know how variable shell colour is. Size just slightly smaller at about 9mm wide, 6 mm high.






Any suggestions gratefully received!
Posted by at

6 comments:

  1. GibsterJanuary 29, 2013 at 12:06 AM

    Don't think either of these are Oxychilus mate. Just not transparent/glossy enough and the ribbing seems way too strong. Roll a few logs in woodland and prod any glossy looking snails with a bit of stick. Oxychilus normally give off a garlicky waft when prodded (but not all of them!) Oxychilus are proper smooth and shiny, as if wet and have blue/grey bodies.

    ReplyDelete
  2. Andy MusgroveJanuary 29, 2013 at 7:39 PM

    Thanks Seth, think I agree. Whittling down the options anyway!

    ReplyDelete
  3. Rich BillingtonJanuary 30, 2013 at 10:54 PM

    What I am identifying as Oxychilus (the draparnaudi pic the other day was 14 mm diam) are much smoother and glassier than these. The unmbillicus looks a lot smaller, shallower and less open than your pics too.

    ReplyDelete
  4. GibsterJanuary 31, 2013 at 9:56 PM

    Hi Andy, this is copied from what I just posted on Mark Lawlor's post, thought it may come in handy here too?

    One thing that I learned today is that O.cellarius has fine brown spotting on the mantle, which O.draparnaudi (the other non-garlicky big one) doesn't have. However, I found 4 large Oxychilus today which were pale-bodied enough for O.cellarius but lacked the spotted mantle. Maybe there's a cryptic species lurking?

    See http://www.habitas.org.uk/molluscireland/species.asp?ID=125

    Cheers, Seth.

    ReplyDelete
  5. Mark G. TelferFebruary 2, 2013 at 8:35 AM

    I've really struggled with snails in the past and I still leave some unidentified. But I'm sure both these are Trochulus. Oxychilus and Aegopinella are smoother and shinier, less opaque.
    Not sure which Trochulus - a side-on shot would be useful. But those paler individuals like your 2nd pic are usually striolatus.

    ReplyDelete
  6. AnonymousFebruary 4, 2013 at 10:39 PM

    Thanks all. I think I'm coming to the conclusion that these are indeed Trochulus striolatus. No sign of any hairs. I've just noticed that this is sometimes known as the Strawberry Snail; probably a coincidence but I do have a load of strawberries growing by the house...

    ReplyDelete

Subscribe to: Post Comments (Atom)