Tuesday, November 23, 2010

Discus catskillensis : Angular Disc

Here is Discus catskillensis, the Angular Disc. I found this one at Ricketts Glen State Park. In most of my books it's listed as Discus rotundus catskillensis, but apparently it now enjoys full species status. It differs from D. rotundus by the angular periphery and lack of blotches.

As a bonus I got to actually witness this snail lay an egg through my microscope. It happened when I was cleaning out the little petri dish terrariums I've been keeping smaller species in. I looked at the snail and it looked odd, like it's neck was bulging. I placed it under my microscope and, sure enough, I was able to see it push out an egg. This was on Nov. 17 and they (there were 4 total) have not hatched yet.

Range map from Land Snails of Limestone Communities and Update of Land Snail Distributions in Pennsylvania (Pearce.

Monday, November 22, 2010

Unknown Valloniidae species

By Sunday I was feeling antsy to get outside. I was sure I was going to get up early and hit Plymouth Flats for migrating waterfowl, gulls, Snow Buntings, and possibly something juicy like a Lapland Longspur. However my flu still had the best of me and I slept in. Eventually by the afternoon I decided I'd take my chances and I'd make my older daughter come with me to do a little hiking around in Frances Slocum State Park.

We didn't stay long but I identified some places that I think will be great for snails come the springtime. Specifically I found some rocky outcrops that I didn't even realize were there when my only focus was on birding.

Checking a couple places I found what I thought was my only snail, a Stenotrema hirsutum (Hairy Slitmouth). I picked it up and put it in a little baggy I had. I also decided to grab a pinch of substrate by it to accompany it on the way home. Fast forward to when I got home and looked at the bag. I noticed a tiny little snail in the dirt.

This snail has a 1.7mm diameter, is umbilicate, obviously has ribs, and has about 3 1/2 whorls. It also has what I think is described as spiral striae (lirate?). The snail itself is mostly colorless but its tentacles are clear with black flecks throughout. I'm fairly sure it is in the family Valloniidae but I'm having trouble getting to species. So I'll talk out my thought process via this blog.

So first things first, I got it to the family basically just because I've had my nose in the books for the past couple months, thumbing through trying to get my bearings. I've paged through looking for other similar families but seem to come up empty.

That brings me to what it could be specifically. Top contenders in my mind seem to be Planogyra asteriscus, Vallonia costata, and Vallonia perspectiva.

Of those three, only one is listed in Land Snails of Limestone Communities and Update of Land Snail Distributions in Pennsylvania (Pearce): Vallonia costata. So it seems like the obvious answer-- after all, I'm a newbie and I doubt I'm finding state records at this level of my knowledge. The one problem is that this snail does not exhibit an expanded lip. Also, it is a little too small. So, perhaps, it is that this is an immature Vallonia costata who needs to grow and develop the telltale lip. But it does mention the spiral striae in Pilsbry.

Planogyra asteriscus measures 1.7 to 2mm and, according to the 1960 Burch key, its range is Maine, Massachusetts, New York, and Michigan. We're an hour away from New York state, so it's a possibility.

Vallonia perspectiva is 2mm or less and its range (again, according to the 1960 Burch key) is New Jersey to Alabama, west to Minnesota, Utah, and Arizona. So, again, it's a possibility, even if not on the state list. It doesn't have that expanded lip.

So that's that. Likely an immature Vallonia costata, maybe something else. I'm going to hold onto it in a petri dish terrarium and see if it grows any and I'll post on this blog any definitive answer.

Monday, November 15, 2010

Neohelix dentifera : Big-tooth Whitelip

On my birthday hike with my older daughter, Emma, to the waterfalls at Ricketts Glen I found this large snail under some leaf litter along the wet cliff-face. I believe it to be Neohelix dentifera, the Big-tooth Whitelip. This snail seems to be close to Neohelix albolabris but is most notably differentiated by the parietal tooth. The common name "Big-tooth Whitelip" rubs me the wrong way as the parietal tooth is so small, but, as this individual measures very low on the recorded diameter size, this is perhaps a younger individual who maybe will earn the "big-tooth" portion of his name. This individual measures a width of 20.7mm and height of 10.3mm.

UPDATE: As you'll notice by the comment to this article, Neohelix albolabris can also have a parietal tooth, so apparently it's not a truly the key difference. Guess I should have read the Pilsbry species account for the similar N. albolabris before reaching my conclusion instead of just using the Burch key. However,  I still think this is probably N. dentifera based on the height of the shell (as also referenced in the comment below). Mathematically it's more depressed than either measurements evidenced in Pilsbry (for N. albolabris or N. dentifera). But, since N. dentifera is the more depressed of the two, I figure it's a good bet.

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

Thursday, November 11, 2010

Xolotrema denotatum : Velvet Wedge

I found this empty shell at Ricketts Glen State Park near the same fallen log that I found the Anguispira alternata. It measures 18.1mm in width. The books list this as 19mm to 25mm but I figure that's close enough. One interesting thing is that I can see what looks like a pupa/chrysalis inside the shell.

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

Wednesday, November 10, 2010

Some Photos From the Leaf Litter

Out, about, and lifting logs I see interesting things. Occasionally I have the wherewithal to snap a photo. Here are a few interesting photos I managed with my point-and-shoot.

Strange Bedfellows

Lifting a piece of bark at Ricketts Glen State Park I found these guys nuzzled up together. I collected the slug but have yet to figure out its definite identity (It's philomycid and has milky white mucus but I'm still trying to find a definitive answer to the mucus colors of these slugs-- I think it barely has the markings of a P. carolinianus but it's hard to tell with it being so heavily mottled). The salamander is likely an Eastern Redback without the red stripe. I just thought it was interesting that these two were found so close.  A month or so previous, when I was just starting out and didn't realize how interested I am in the native slugs, I had found a philomycid with a Spotted Salamander nearby-- but nothing as close as the cuddle these two exhibited! Thinking now I wish I had collected the philomycid I found with the Spotted Salamander to see if, over the years of collection, I can find a connection between which species of philomycids and salamanders are found together.

Bee Hibernating

Last week I was lifting logs and found this sight, a bee apparently hibernating. The interesting thing about this, though, is that after I came home and downloaded the photo I grabbed I noted some larvae on the bee's eye. I wonder if it's feeding on the bee while it remains helpless in its torpid state. Make sure to click on the photo to enlarge and see the larvae.


Here I lifted a piece of plywood in the area where I had found all the Cepaea nemoralis and found this fellow. A quick email to local naturalist Rick Koval proved it to be a Northern Brown Snake.

A Bonus Studio Shot

 This is actually a studio shot. I set up my office to be my macro studio. This Cepaea nemoralis is on a gourd and the background is just my wall color. I thought it made for a cool monochromatic shot.

Tuesday, November 9, 2010

Anguispira alternata : Flamed Tigersnail

I'm fairly sure this is Anguispira alternata, the Flamed Tigersnail. This fellow is pretty dull compared to some of the photos I've seen online but Pilsbry mentions the snail being duller in late seasons. I found this fellow along with a couple of empty Polygyrid shells near a fallen tree at Ricketts Glen State Park (still just barely in my own county). I tried using Pilsbry to get it to subspecies/form but couldn't do it. Maybe down the road when I'm more knowledgeable I'll be able to go back to this guy and accomplish that task.

This specimen has a width of 18.1mm and height of 8.6mm.

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

Monday, November 1, 2010

Zonitoides arboreus : Quick Gloss

This is Zonitoides arboreus, common name Quick Gloss. I found many of these tiny snails at Frances Slocum State Park on the mountain bike path the same day I found my Philomycus togatus. I've just been lazy/busy on making an identification. Actually it's two individuals I found at Ricketts Glenn that have been consuming the time I have to study identification-- and I still haven't id'd them.

Anyhow, click on the photos to enlarge. The two colors are pretty cool-- dark up top, clearish down bottom.

Range map from Land Snails of Limestone Communities and Update of Land Snail Distributions in Pennsylvania (Pearce)