edrinkwater's picture

Snail 25

Observed: 17th July 2012 By: edrinkwateredrinkwater’s reputation in Invertebratesedrinkwater’s reputation in Invertebratesedrinkwater’s reputation in Invertebrates
Snail 25
Description:
Identifications
Species interactions

No interactions present.

Comments

edrinkwater's picture

Size

Ops, I forgot to put the size on this one. It is between 6-7mm. Thank you.

dejayM's picture

possibly Lymnaea truncatula

Is it too big for P.antipodarum at 6mm? Usually at 2-3mm
A lookalike is Lymnaea truncatula (at 7-12mm)
ðj

martinjohnbishop's picture

Not too big

http://en.wikipedia.org/wiki/New_Zealand_mud_snail
The average height of the shell is approximately 5 mm; maximum size is approximately 12 mm. The snail is usually 4–6 mm in length in the Great Lakes, but grows to 12 mm in its native range.

Being a prosobranch with an operculum the lip make a full circle as in the photograph. Lymnaea truncatula is not like this, the lip not being thickened against the body wall but only at the free edge of the last whorl.

Regards,
Martin

dejayM's picture

separation

Yes Martin, thanks.
I am about to post up a sighting from a new area near Inverness. They are nearly black, certainly very dark grey and none, in the thousands I found, were bigger than 2.5mm.
Following your link to this http://en.wikipedia.org/wiki/File:Potamopyrgus_antipodarum_shell.png suggests the rim (lip) of the opening to be complete all 'round.
But this http://en.wikipedia.org/wiki/File:Galba_truncatula.jpg (L.truculata) is incomplete.
Do you think that's a fair indicator for separation (from a photo)?
ðerek

martinjohnbishop's picture

Correct

Yes, that is the point I was trying to make.
Martin

dejayM's picture

my post