identification ?

[vriska]

hey y'all. im pretty new here but i know like, next to nothing about identifying snails. i was wondering if i could get a hand IDing these little guys i recently caught.

the big guys seem to all be the same species, but i think the littlest one there is something else entirely. i live in central texas, so that might narrow it down a little. they were mostly under/around my backyard fence bc it got pretty hot & dry soon after a couple days of rain.

anyway, here's a pic of these guys having some brunch (my phone camera isnt great lol. also sorry if the picture's huge, im on mobile rn)

[morningcoffee]

May 6, 2021 2:35:38 GMT vriska said:

hey y'all. im pretty new here but i know like, next to nothing about identifying snails. i was wondering if i could get a hand IDing these little guys i recently caught.

They could possibly be Otala lactea (which are an introduced/invasive species in Texas) but I'm not confident of that ID. We might need some better photos showing different angles, and some shell measurements etc.
idtools.org/id/mollusc/factsheet.php?name=Otala%20spp.

wolf - any thoughts?

[wolf]

Hi vriska and hi morningcoffee,

hmm....... . Hard to tell with so little information . I see there two different species, too. The small specimen has rather narrow whorls.

Yes, might be some Otala species (must be a rather bright/pale variety in this case). The large specimens seem to be adult. So it is helpfull to judge the inner margin of the opening. Should be more or less dark in Otala species (Massylaea vermiculata: white).

And, true enough, we need better pictures at different angles (a bottom view, f.e., to see the umbilicus).

Kind regards: wolf

[vriska]

first i wanna say thanks for the replies. this morning i took some more pictures, & did what i could to try and measure their shells.
i dont wanna get too image-heavy so ill just link to the albums. this first one is the bigger guys, closer up to better see their patterns & shape, and some of their undersides: imgur.com/a/oJGPI1R
these two are roughly the biggest of the bunch, shell-wise. their shells are about 1 1/2 inches wide, and 1 1/2 inches tall (3.81 cm). theyre very round lads. the smallest out of them is about 1 inch around (2.54 cm)

and some similar pics of the little guy: imgur.com/a/ZvJZUVg
his shell is sort of semi-transparent, not as thick as the bigger snails. he has a darker stripe all around, & unlike the big guys has a little hole on the backside of his shell. measuring him was kinda tricky. i wanna say his shell is about 0.59 inch (15 mm?) wide, because i had a penny for scale, and hes about 5 mm smaller than a penny. his height is about the same as his width. 

thankfully they were all having a nap so it was easy to photograph em. i hope this is a bit more informative ! and thanks again

[wolf]

Hi vriska,

thanks a lot for your trouble - the pics are much better now.

Concerning the little specimen: it reminds me of Bradybaena similaris (= "Asian trampsnail"). Perhaps you can compare with this species. It was abducted anthropogenically into several countries in the tropics and subtropics. Please note that there can be a brown band at the periphery (as in your specimen), but some lack this band (it seems to be a simple dominant-recessive inheritance mechanism). The umbilicus (= "navel") at the bottom should be nearly totally open; sometimes it is partly (!) covered by the margin of the opening.

Concerning the large ones: they might well be some Otala species (as morningcoffee supposed yesterday). Both Otala lactea and Otala punctata are extremely variable in color (in Florida there even are albinotic variants known). Normally in Otala lactea the inner margin of the opening is rather dark-brown, in Otala punctata the brown color of the inner opening is less intensive and normally lacks at the palatal side. The best way to tell the difference between the two species is to judge the lower part of the opening (in adult specimens): Otala lactea has a rather prominent dens-like thickening which lacks in Otala punctata. In both species the navel should be closed.

Have a nice time, kind regards: wolf

[Love snails and slugs]

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