Thursday, February 17, 2011

Punctum minutissimum : Small Spot



Right before I left Pennsylvania I decided to grab some photos of micro snails I found in the soil sample from before the snowfall. The soil sample came from the mountain bike path side of Frances Slocum State Park and yielded about 20 or so micro snail individuals. The above snail, is Punctum minutissimum, commonly called Small Spot.

This little fellow photographed measures a mere 1.09mm. If remember correctly, the umbilicus measures 0.28ish mm, but I am definitely sure that the umbilicus is contained about 3.8 times in the diameter (that math adds up). Everything pretty much jives with Pilsbry's opening paragraph about this creature:

The shell is very minute, depressed conoid, umbilicate, the umbilicus contained about 3.7 times in the diameter; thin, of corneous or very light brown tint, somewhat translucent, shining. Initial 1 1/2 whorls smooth, the rest sculptured with  close, somewhat unequal very delicate striae in the direction of the growth lines...

The only other known Punctidae known in the state of PA is Punctum vitreum. Size seems to overlap, but P. minutissimum is slightly smaller. A key difference seems to be that P. vitreum has the widest ribs of the Punctidae (dlia.org landsnail.pdf which I'm pissed because they took their snail pages offline, I should have crawled the site and saved it, but the pdf is still available if you can find it and it has pretty much all the info anyway). Another interesting tidbit from Pilsbry:

 Under the binocular, P. minutissimum looks as if it were molded out of bronze , but P. vitreum appears as if it was cut from yellowish crystal.
On a personal note, I'm still having a tough time with micro snails. My microscope is 40x and so I really can't get fine sculpture when looking through. But snapping a photo helps as I can zoom in a little more. Another problem is just handling them-- as evidenced by the photos in this post. I have to come up with systems to better handle my micro snails. I've already lost some interesting snails, for instance, crushing a shell which was either a Columella species or immature Ventricosa or Gastrocopta species. Very disappointed by that one. For someone who's very coordinated when it comes to things like sports and dancing, I turn into a proverbial bull in a china shop when micro snails are involved.



Range maps from Land Snails of Limestone Communities and Update of Land Snail Distributions in Pennsylvania (Pearce) with my Luzerne county added to range (in orange). Formerly unknown to Luzerne County.

Thursday, February 3, 2011

The Future of My Snailing

The one thing I like about snailing Luzerne County, Pennsylvania is that it is an understudied area. All my findings seem very valuable in my eyes because there really aren't a lot of records from the county. In fact, as I leaf through Pilsbry, my county seems very rarely represented in mentions about species, even those that are known to occur in surrounding counties. My county is left blank in many of the Hubricht maps. It's kind of like my own way of feeling like a pioneer. I'm in mostly uncharted territory.

However, in a week I begin my new job at the Cornell University Lab of Ornithology as Interactive Web Designer for the Citizen Science Department. In such an area, where scientists abound, is it already well scoured? Will it be harder to find shells because there are more collectors? Is my beginner's knowledge and elbow grease much less valuable in the situation? Maybe, who knows. I won't know until I get up there and can start sniffing around for these answers.

But a more positive way of thinking about it is that I may be able to find someone to apprentice. Let's face it, right now, I'm practically an island when it comes to snailing. I really have nothing but some books well older than me (and in some respects outdated due to changes in taxonomy, etc) to try to parse and hope I'm correct. It might be nice to have someone to correct my mistakes in real time and offer insight. At the very least I'll have the Cornell library and can hopefully find all the articles that I've wanted but have yet been able to procure.

I'll still actually be in Luzerne County most weekends. However, I don't foresee a ton of time to devote to birding/snailing when I'm here. Of course, I'm sure I'll be able to steal a little time here and there.

A couple asides:

Besides the Anguispira I seem to have a litter of Zonitoides nitidus!

Also, I'm pleased that I've resumed work on my land snail iPhone app. I'm still researching all the species (which I've expanded to all of the northeast- from PA to ME). I'm also including snails that are known to the norther counties of MD, DE, and WV as they seem like they are at least hypothetical to the range.