This morning, Matthew Cobb sent me the needle’s-eye photo below, and then reader Dom conveniently sent the article from which it was taken: a new paper in ZooKeys by Barna Páll-Gergely et al. (reference below) describing what are among the smallest snails in the world. And when I say “small,” I mean TINY!
The group of researchers described seven new species of snails recently collected in Guangxi Province, China. One of them, Angustopila dominikae (photo below), has a shell height of about 0.9 millimeters, and a width of about 0.8 mm, with an aperture about 0.3 mm across. As the authors note, these are close to the smallest land snails ever found, but don’t quite hold the record:
These data suggest that Angustopila subelevata sp. n. and A. dominikae sp. n. are amongst the smallest land snails ever reported if the largest measurement of the shell is considered. If however, shell volume is calculated according toMcCain and Nekola (2008) and Nekola (2014), there are even tinier land snails (e.g.Punctidae spp) occupying the lowest rung of the volume/size scale.
Here’s the holotype (the specimen used to name the species, and which will serve as its representative in a museum) of A. dominikae:
Well, the key gives an idea of how small it is, but the picture below really tells the tale. Remember, that’s an adult snail! A camel might not fit through the eye of a needle, but these snails can; ergo they can go to Heaven.
But these aren’t close to the smallest of all snails: that record goes to marine snails less than half the size of the one shown above:
. . . The smallest snails are, however, certainly marine species. The smallest recorded gastropod seems to be Ammonicera minortalis Rolán, 1992, ranging in size from 0.32 to 0.46 mm.
You can find a paper on this species, found in Cuba, Florida and the Caribbean, here. And here’s a photo with scale:
That is one small snail.
h/t: Dom
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Páll-Gergely, B., Hunyadi A., Jochum A. and T. Asami. 2015. Seven new hypselostomatid species from China, including some of the world’s smallest land snails (Gastropoda, Pulmonata, Orthurethra). ZooKeys 523:31-62.
I wonder what is the advantage of a shell if it’s so small? Can it offer that much protection at such a tiny size?
For land snails the shell helps reduce water loss by evaporation. But for tiny marine snails yes I wonder too what the point is. Many snails have lost the shell altogether (and become slugs), and that has happened often in different lineages, so it’s not too hard for snails to do if the costs of the shell > the advantages. Maybe these are cheap shells so the costs are low?
Though some slugs retain a vestige of a shell
eg http://snailstales.blogspot.co.uk/2005/04/slugs-shell-flimsy-evidence-for.html
I always thought it was the other way around, as in snails are slugs that grew a shell.
Wow. Next time we got to the beach, I am going to look for some teeny tiny shells!
Nice to get out of bed reading this.
Makes me think of the late Oliver Sacks and his words: “Be dedicated not only to science but to wonder in the broader sense.”
Snails and wonder 🙂
One wonders why a group would evolve to be so tiny. I suppose they could crawl among the sand grains, making an effectively vast and food rich environment that way.
Another interesting aspect about smallness is that complex organs like a brain that controls a full range of snailey behavior must be miniaturized to only a few cells. So nature is amazing in what she can do.
Ah…that would explain it. It’s not that “Heaven is for reals,” it’s that “Heaven is for snails.” An obviously easy mistrake to make!
b&
Very cool. Thanks for the photos too. Tiny little guys, aren’t they? From specs to giant clams.
What is the recent Cat in the Hat against the Snail in the Nail?
[OK, both were cute. Still…]
I salute Bieler & Mikkelsen for telling Ammonicera from Foraminifera
Come to think of it, these snails are kind of in the ecological niche of the foramins.
Very neat!
I used to find some very tiny gastropods in my reef tank–so much life was between the grains of substrate. Wish I had a clue as to where to find the pictures.