31 May 2009

Cepaea nemoralis in Maryland

Early last week, a reader e-mailed the picture of a snail shell he had found in Maryland and asked for an identification. To my surprise, it turned out to be Cepaea nemoralis, a native of Europe introduced to a few places in the U.S. Subsequently, I got from the reader the GPS coordinates and detailed directions to his collection spot along with the warning that there was a lot of poison ivy in the area.

The location turned out to be only about a half an hour drive from where I live. So this morning I took my son along and went there. The exact spot was surrounded by an impenetrable wall of poison ivy. While I was scouting the area and trying to figure out what to do, my 14-year old son, who has been trained since the age of 4 to spot snail shells, announced his first find. It was indeed an empty Cepaea nemoralis shell from the edge of the busy highway next to us. Empty shells turned out to be quite abundant among the grass along the metal guardrail separating us from the highway. Soon we had close to 40 shells.

CepaeaNemoralis1

Here is our collection spot.

CepaeaNemoralis2

The live snails took longer to find. Eventually, I spotted them on damp soil inside the cavities around the bases of the guardrail posts.

CepaeaNemoralis3

Its brown lip distinguishes Cepaea nemoralis from the similar Cepaea hortensis. The latter, known from some islands off the coast of northeast U.S., may or may not be native to North America.

CepaeaNemoralis4

I have no idea how and when these snails were introduced to this spot. We will probably write a short paper to publish this new record for Maryland. Until then, I will keep the exact location confidential.

Part 2

29 May 2009

The loneliness of the lone long distance driver

As I mentioned in this post, every now and then I try to imagine what it would be like if I ended up being the only person left on earth. The first few days would probably be exciting as I went around doing anything I wanted to do with absolute freedom. It would be kind of fun. I wouldn't have to wash the dishes or do the laundry to begin with. Anytime I needed something clean, I could walk into a store (or a neighbor's house) and get it without having to pay for it or feeling guilty about it. I could ignore all the traffic lights and speed limits and park my car in the middle of the road. Imagine that!

And then, loneliness would set in.

Once I realized that I might never see, touch or talk to another human being, because there were none left besides me, I would probably gradually descend into a state of delirium.

On the other hand, one could never be sure that there still wasn't another person left somewhere on earth.

How could you possible know that you were the only person on earth? As long as telephone service and electricity were available you could attempt to make random phone calls or get on the Internet and search for signs of human activity. Perhaps you would run across a blog post from a few hours ago or receive an e-mail. Even an offer for partnership from Nigeria would bring tremendous joy. Imagine that!

But once the electricity and the phone services got cut off due to lack of maintenance or some other reasons, the only way to establish contact with anyone who might still be out there would be by physically searching for them.

Since there would practically be an unlimited supply of gasoline for a single person, one could get into a car, any car, and start driving around in hopes of finding another person.

The hope of finding someone else, perhaps in San Francisco, or Peru, or Singapore, or Istanbul, could possibly help me maintain my sanity. How would someone, who was not much of a sailor and who couldn't fly a plane, cross over to Asia, though?

The next post in this series is here.

28 May 2009

A screwed up snail

BatillariaMinimaScrewy

One of the interesting finds during last month's trip to Florida was this Batillaria minima with a funky shell. Well, I think it's a Batillaria minima; I found it among Batillaria minima and the microsculpture of its shell, its operculum and the morphology of its head look like those of Batillaria minima. But if you think it may be a different species, let me know.

Here is what a normal Batillaria minima looks like.

BatillariaMinimaNormal

What may have caused this snail's shell to resemble a screw? I don't know. There are no injury scars on it and because the screwiness starts near the apex, I suspect the cause was internal. Perhaps a parasitic infection? Batillaria are known to carry trematodes.

I have the snail here, by the way, and it's still alive.

27 May 2009

Bathhouse lesbians of Constantinople

Ogier Ghiselin de Busbecq (1520/1521-1592) was the Austrian Emperor Ferdinand’s ambassador to the Sublime Porte during the reign of the Ottoman Sultan Süleyman the Magnificent. Busbecq spent 8 years in Turkey, mostly in Istanbul. He is best known for the 4 long letters, originally in Latin, he sent to his friend Nicolas Michault that were later published as a book, The Turkish Letters*.

Busbecq’s letters are collections of his personal experiences as well as hearsay accounts of topics as diverse as the internal strifes of the Ottoman Palace, the lives of the ordinary Turks, the menagerie Busbecq kept at his house and the frequent epidemics of the plague that killed more than one of Busbecq’s friends. This paragraph is from his 3rd letter dated 1 June 1560.

The great mass of women use the public baths for females, and assemble there in large numbers. Among them are found many girls of exquisite beauty, who have been brought together from different quarters of the globe by various chances of fortune; so cases occur of women falling in love with one another at these baths, in much the same fashion as young men fall in love with maidens in our own country. Thus you see a Turk's precautions are sometimes of no avail, and when he has succeeded in keeping his wives from a male lover, he is still in danger from a female rival!

OttomanWomen2
16th century Istanbul woman [and her slave?] on the way to the bathhouse. From Asırlar Boyunca Istanbul [Istanbul Throughout the Centuries] by Haluk Şehsuvaroğlu. Undated (ca. 1955).

One gets the impression from Busbecq’s account that lesbianism was unheard of in Europe at that time. And one wonders how Busbecq knew about the “girls of exquisite beauty”, for men would not have been allowed in womens’ bathhouses and the women would not have ventured outdoors without covering their faces.

OttomanWomen1
Istanbul women at a spring outing (ibid.)


*An 1881 version featuring the English translations of Busbecq’s letters along with information on his life by Forster and Daniell is available at the Internet Archive.

26 May 2009

Black cat #14125B

BlackCat14125B

25 May 2009

Phil spills his guts out, ends up in garbage

Remember cassettes? I bought my last one, I think, in 1992. But I still have about 100 cassettes and a working cassette player that I keep in the basement. As you can imagine, almost all of the cassettes are from the 1980s; but there are a few from the late 1970s that are, amazingly, still playable and with a good enough sound quality to accompany a late night snail dissection.

Cassettes had a propensity to malfunction (the surviving ones still do). Sometimes they could be repaired by removing a bad section and reattaching the loose ends with tape. But I don't waste my time with such things anymore; at the slightest sign of trouble I toss them in the trash.

cassette1

This morning I pulled out the cassette from the player to find out that a lengthy section of the tape had come out.

cassette2

It turned out to be Phil Collins' No Jacket Required. And look at this fine mess he got me into.

cassette3

So long Phil. Now I have about 99 cassettes left. I will continue this slow process of attrition until either I run out of cassettes or the cassette player, already about 20 years old, goes kaput.

24 May 2009

Melongena corona attempting an escape

Melongena corona is an intertidal snail common on sandy bottoms around Tampa, Florida. Although it is primarily an aquatic species, it never appears awkward when it is outside the sea at low tide: sometimes it takes the easy way out by burying itself in the wet sand; at other times it crawls on until it reaches the water*.

Back in April when I was in Florida, I kept a couple of Melongena corona for a few days in an improvised aquarium—a large plastic container of sea water, the water in which I replaced partially once a day. Several times I observed the captive snails leaving the water by climbing up the sides of their container.

MelongenaCorona4
The wide yellow thing against the side of the aquarium is the snail's foot.

I don't know if they ever leave the water voluntarily in the wild. Their tendency to do so in captivity may have been caused by the less than optimum conditions they were subjected to. But it nevertheless demonstrates an intertidal snail's occasional willingness to face the challenges of life outside the water.


*This dichotomous generalization is, of course, not entirely correct. But that will be the subject of another post.

21 May 2009

Do hermaphrodite snails have twice the fun?

Over at Deep-Sea News, this week is Sex Week. If you mosey over there, after you finish reading this blog first, you will find many an interesting article providing deep penetration into this most titillating subject matter.

I spend most of my research time studying hermaphroditic gastropods, that is, snails that have both male and female organs. Most terrestrial snails are in the group Pulmonata and all pulmonates are hermaphrodites. Here is a pair of such snails, Oxyloma retusa, mating (details here).

OxylomaRetusaMating

When one is observing a couple of hermaphrodites mating, one naturally wonders if the action is anatomically reciprocal. In other words, whether each snail is deploying its penis. Alternately, one snail could act as a male, while the other as a female. It turns out that in some pulmonates mating is anatomically reciprocal, while in others unilateral (for example, see Davison & Mordan, 2007).

When I was studying the reproduction of Oxyloma retusa, I decided that the easiest way to determine if their mating was anatomically reciprocal or unilateral was by separating a mating pair slowly while watching them closely. By using this forced withdrawal method on many pairs of snails, I eventually determined that in the majority of the pairs mating was anatomically reciprocal. Further details are in my forthcoming paper (Örstan, in press).

Here is a short video that shows the separation of a pair of mating Oxyloma retusa. The snail between the fingers of my left hand was the snail on top or on the right side of the shell of its partner (see the picture above) and the one in my right hand was the snail on the bottom. If you look carefully, near the end of the video you will see the penis of each snail coming out of the vagina of its partner.

video
One nice thing about this method is that the snails are not harmed.


Davison, A., and P. Mordan. 2007. A literature database on the mating behavior of stylommatophoran land snails and slugs. American Malacological Bulletin 23:173-181.
Örstan. A. Reproductive biology and the annual population cycle of Oxyloma retusum (Pulmonata: Succineidae). American Malacological Bulletin in press.

20 May 2009

A tree named Elbert

Elbert

19 May 2009

Gopher tortoise in Florida

GopherTortoise1

I encountered this big guy in a park in Pinellas County, Florida back in April. Butch Norden has identified it as a Gopher Tortoise (Gopherus polyphemus). This species, a native of southeastern U.S., is generally threatened throughout its range, probably mostly due to habitat loss to development.

Here is a close-up of the head. I noticed later while looking at the fully enlarged pictures on the monitor that there is something stuck under its eye. I don't know what it is, but it doesn't quite look like a tick (here is a turtle with a tick).

GopherTortoise2

18 May 2009

Wolfram|Alpha fails to impress this blogger

My 1st inquiry for Wolfram|Alpha, Stephen Wolfram’s newly unveiled “computational knowledge engine” was this:

“snail shell”

And this is what I got back:

Wolfram|Alpha isn't sure what to do with your input.

I look under Tips for good results. It says, “Don’t use long complete sentences; just enter the minimum number of words needed to communicate.” My inquiry can’t possibly be shorter than those 2 words. Another tip was, “Wolfram/Alpha answers specific questions rather than explaining general topics Enter '2 cups of sugar', not 'nutrition information'. So, maybe I wasn't specific enough. I got more specific:

“composition of snail shell”

Wolfram|Alpha isn't sure what to do with your input.

Do I also have to provide the answer?

“calcium carbonate in snail shell”

Wolfram|Alpha isn't sure what to do with your input.

“largest snail on land”

Wolfram|Alpha isn't sure what to do with your input.

“penis of snail”

Wolfram|Alpha isn't sure what to do with your input.

May I suggest to Wolfram|Alpha that it can take my input and stuff it?

17 May 2009

How many quail eggs does it take to make one omelet?

QuailEggs1

Yesterday Whole Foods Market was displaying these quail eggs among the peppers, carrots, mushrooms and the like. The idea must have been to attract attention to a new product by creating a stark contrast; it worked with me. I couldn't pass the opportunity to try out an omelet made with quail eggs.

They are the eggs of Japanese or Coturnix quail. The egg shells are covered with interesting splotches of brown.

QuailEggs2

And they are tiny compared to chicken eggs.

QUailEggs3

Although the egg shell was thin, the membrane inside was difficult to puncture; as a result, the process of getting everything out of the eggs was a bit messy and slow. Notice that the insides of some eggs were greenish blue.

QuailEggs4

Here is the finished omelet stuffed with mushrooms. The red thing is paprika. I also added black pepper and sage. It was good, but I don't know if I can tell it from an omelet made with chicken eggs in a blind test.

QuailEggs5

It took 11 quail eggs to make that omelet. I may scramble the remaining 7 eggs for tomorrow morning's breakfast.

15 May 2009

It ain't nothin' but an enlightened hoop snake (with a strong swallowin' response)

A few days ago, Budak of annotated budak put up a link on his facebook page to the blog of the Maruyama Zoo in Sapparo, Japan, where it seemed one of the resident snakes had been photographed in the process of swallowing its own tail*.


Photo from Sapparo Maruyama Zoo.

This snake had obviously figured out that the surest way to achieve Zen enlightenment was by thoroughly knowing one's self and the only indisputable way of thoroughly knowing one's self was by, well, eating one's self.

I couldn't pass the opportunity to forward this bit of profound reptilian achievement to several of my friends. One of them, Carl Christensen, responded with his insightful observation that the subject snake was a legendary hoop snake. For more information, I resorted to Clifton Johnson's What they say in New England (1897):
It is bad enough to have a snake in your stomach, but you are even worse off if you meet with one of these hoop-snakes. Let one of those chase you, and you are a goner. They ain't afraid of a man no more'n nothin', and they can run faster'n any horse goin'. The way the snake does is to pick its tail up in its mouth, and then whirl over and over like a hoop. His tail is sharp-pointed and hard like a spike. When he catches up with you, he just takes his tail out of his mouth, and jabs it into you. Oh, I tell you, you'd better swallow a dozen snakes rather'n get one o' these hoop-snakes after you.
Butch Norden, on the other hand, who is an expert on snakes and related creatures, offered a more erudite explanation: "It happens with captive snakes from time to time. They are at the stimulus-response level of behavior, and they can get confused, especially when kept in forced contact with others so that scent is transferred from one body to another. They do have sharp teeth, and this must hurt, but the swallowing response is very strong."

Now we are all enlightened.

HoopSnake2
From What they say in New England

*After I complained to Budak that I couldn't read Japanese, he thankfully posted a link to this brief English summary.

14 May 2009

Distribution of my reaction times

One of the many tests at cognitive fun! is the Visual Reaction Time test. It is a simple test: position the cursor within the four arrows close to the red dot and then click the mouse as soon as the large green dot appears. The aim is to click in less than 250 milliseconds, although I don’t know the significance of that particular number.

I did 100 sequential tries this morning, while writing down the time for each. I started the test assuming that the distribution of my times would be normal, but soon it dawned on me that my performance had a lower limit, which appeared to be 187 ms. After I had scored several of those, it became obvious that the distribution wasn’t going to be normal*. Here is the histogram for my 100 time scores.

ReactionTimes1

The 4 longest times were the results of distractions; I had looked away for a moment or something like that.

Here is the histogram for all the values at or below 300 ms. It is a peculiarly skewed distribution. There is a cluster of very short times (187 and 188 ms), then a gap followed by another cluster and finally, a few long values.

ReactionTimes2

My average for all 100 tries is 229 ms. If the 4 longest times (all above 297 ms) are deleted, the mean becomes 218 ms.

Give it a try and see how fast you can react to green.


*Theoretically, any and all normal distributions extend from negative to positive infinity, the only differences between the individual distributions being the mean and the standard deviation values.

13 May 2009

A peculiar anthill

anthill
Photographed near Tampa, Florida last month.

How do they build that overhanging rim around the opening?

12 May 2009

Gastropods at 100% humidity

In this post, I wrote about the detailed drawings of experimental setups that they used to include in the old scientific papers. Here is another such drawing, this time from a 1934 paper*.

Fig7

Howes & Wells, the authors of the study, noticed that there were irregular changes in the body weight of the snail Helix pomatia over many days. They determined that the weight changes were mostly due to changes in the water contents of the snails. Then they wanted to see if the snails kept in an atmosphere saturated with water vapor would still undergo similar weight changes**. The figure above shows the setup they used to create a container of air at 100% humidity.

Of course, the simplest thing to do would be to seal the snails in a jar partially filled with water. But they intended to keep the snails in there for many days, so they needed to supply the animals with fresh air also saturated with water vapor. That’s what the tank labeled A did: the water inside the tank was heated and then the air saturated with steam was pumped, after it was cooled down, to the container labeled D in which were the snails. There was also water at the bottom of that container and even a “wooden bridge for the animals to climb up and down on” (that must be that stick dipping into the water). Finally, the tubes in part F contained a manometer to regulate the rate of air flow.

Last weekend I did an experiment with slugs to determine if they could absorb water vapor from air saturated with water. Basically, I needed a setup similar to the one Howes & Wells used, but because I was going to keep the slugs in the saturated air for not more than 6 hours, I went the simpler way. Here was my setup.

SaturatedAir1

The slugs (Megapallifera mutabilis) that had been dehydrated previously (using Drierite) were suspended from a mesh sealed around the cap of a large plastic jar (that once held chocolate biscotti). There was a shallow layer of water on the bottom. The mesh prevented the slugs from contacting the water; they were exposed only to the water vapor in the air.

And here is an electronic hygrometer recording the humidity and the temperature inside the jar thru a hole in the lid. (The hole was otherwise sealed with tape.) The humidity was at 99.9%, the end of the scale of the hygrometer.

SaturatedAir2

If I repeat the experiment, I may consider supplying the slugs with fresh air. But it would take some thinking and tinkering before I can come up with a modified setup that would do the trick without being not so complicated as that used by Howes & Wells.


*N. H. HOWES & G. P. WELLS. The Water Relations of Snails and Slugs: I. Weight Rhythms in Helix pomatia L. J. Exp. Biol. 1934 11: 327-343. (pdf from this page.)
**Yes, the snails' weights fluctuated even in saturated air, but the amplitudes were smaller.

11 May 2009

Boat-tailed grackle from Florida

BoatailedGrackle1

I photographed this bird in Florida last month at a beach that had picnic tables. The bird was obviously used to having food thrown at it by the picnickers and probably also cleaning up after them. It was rather tame and while I was getting my equipment out of the trunk of my car, it kept watching me from the top of a nearby rock and even landing near me in expectation of some morsels. But I only took its pictures.

BoatailedGrackle2

My meager birding talents did not let me identify it. So, I e-mailed the pictures to John, who writes A DC Birding Blog, and he identified it as a female boat-tailed grackle (Quiscalus major). Note that the males are black and look quite different than the females.

Also note how the bird was perched on that rock with one leg lifted up.

BoatailedGrackle3

10 May 2009

New comment policy

Some annoying assholes have been leaving fake comments with links to commercial sites. Comments are now subject to approval by the management until the situation improves. We apologize for any inconvenience.

What's cookin' in my oven?

If you carry out most of your scientific research in your home like I do, then you too may be taking over and using the stove and the refrigerator in your kitchen from time to time for purposes not even closely related to the preparation or storage of food.

I use the kitchen oven occasionally to regenerate Drierite. Drierite, a trademark of W. A. Hammond Drierite Co., is an excellent all purpose, and cheap, drying agent made from calcium sulfate. Indicating Drierite contains cobalt chloride, which turns blue when it is dry and pink when it is wet, thus letting the user know that it is time to replace the Drierite. Here is some Drierite that turned pink because I was using it to dehydrate some slugs as part of an experiment (relax, the slugs are okay).

Drierite1

And here is the same stuff after an hour at about 200 °C (~400 °F) in the kitchen oven.

Drierite2

Now it is ready to once again suck the water out of more hapless slugs. It's all in the name of science.

08 May 2009

Clearwing moth from the sidewalk

ClearwingMoth1

This dead moth was today's find on a sidewalk at a relatively quiet corner of an otherwise busy shopping center. It is probably a hummingbird clearwing (Hemaris thysbe).

Their wings are indeed clear.

ClearwingMoth2

Under the microscope, the clear portion of the wing is mostly free of scales and has the look of cellophane. It must consists of dead cells that are completely devoid of molecules that absorb light in the visible spectrum.

ClearwingMoth3

07 May 2009

How to intimidate your enemies, circa 1097

The first major city that the armies of the First Crusade sieged on their way to Jerusalem was Nicaea (now Iznik) in northwest Asia Minor. Nicaea was then the capital of the Seljuk Turks who had captured it from the Byzantine in 1077.

Thomas Asbridge writes in The First Crusade (p. 126): “Any medieval army knew the profound significance of morale amid the slow grind of siege warfare, and exchanges of horrific acts of brutality and barbarism were commonplace.” Asbridge then relays the crusaders’ intimidation tactics after the first battle between the Christian knights and the Turks, which had ended with the retreat of the latter (p. 126):

‘the Christians cut off the heads of the dead and wounded and as a sign of victory they brought them back to their tents with them tied to the girths of their saddles’. Some were stuck on the ends of spears and paraded before the city walls [of Nicaea], others were actually catapulted into the city in order to cause more terror among the Turkish garrison’.
Asbridge notes that in retaliation, the Turks pulled up the bodies of the dead crusaders using hooks tied to ropes and then left the corpses to rot while suspended from the walls of the city.

Crusaders
Drawing from here.

Several months later during the siege of Antioch (later Antakya, now Hatay near the border of Turkey and Syria), more of the same methods were deployed. One day, some Turkish soldiers were captured during a skirmish outside the city. These “were led before the city gate and there beheaded, to grieve the Turks who were in the city.” In return, the Turks not only started killing the Christians in the city and throwing their heads outside the walls, but also resorted to a more spectacular retribution (p. 168):
The Muslims regularly dragged the Greek Christian patriarch of Antioch, who had until then lived peacefully in the city, up to battlements, hung him upside down from the walls and beat his feet with iron rods, in sight of the crusaders.
Lest certain folks out there now start with their usual rantings about “barbaric Turks”, let’s read what Asbridge wrote next:
In viewing such events, we must try to temper our instinctive judgement with an awareness that in the eleventh century war was governed by medieval, not modern, codes of practice. Within the context of a holy war, in which the Franks were conditioned to see their enemy as sub-human, Christian piety prompted not clemency but, rather, an atmosphere of extreme brutality and heightened savagery.
Once one manages to attain a detached and objective position, the whole Crusade history becomes almost as entertaining as a Monty Python movie with plenty of ridiculous violence interrupted with episodes of looting, pillaging and kidnappings of young women and good looking boys. Even the ordeal of the patriarch of Antioch appears comical, the poor man's sufferings notwithstanding.

Another post about the 1st Crusade is here.

06 May 2009

A possible case of simple zonation in Tampa Bay

PhilippeParkZonation1

I took this picture while hanging over the edge of a concrete wall above the waters of the Tampa Bay in Florida. I was in Philippe Park in Safety Harbor.

A worldwide characteristic of rocky shores is the vertical layers, or zones, of animals and plants extending from the species that are almost always immersed to those that are only wetted by the highest tides or wave splash. Such zones are present even on shores where the tides are imperceptible (example).

In this case, there were apparently only 2 species present: a zone of oysters right at the edge of the water, followed by a zone of small barnacles. A closer look would undoubtedly have revealed additional species within those 2 zones.

PhilippeParkZonation2

Because the picture was taken from above, the original was upside down, which I reversed before posting here.

05 May 2009

Miraculous likeness of Marilyn Chambers appears on restaurant griddle


Photo from Los Angeles Times.

The Los Angeles Times reported a ridiculous claim that a grease stain on the griddle of a Mexican restaurant in Calexico, California is a likeness of the Virgin Mary. Get serious, folks. Any sane man over the age of 18 can tell you that what we have here is a dead ringer of the recently deceased porn star Marilyn Chambers. Why, I even see a phallus-like stain towards the left.

Hail to Saint Marilyn, Our Lady of Fornication!

04 May 2009

Seven kilos of pickled slugs

PickledPhilomycus1

Until the weekend, I am in possession of several jars of philomycid slugs preserved in alcohol. To make the long story short, Megan Paustian, who is researching these slugs for her Ph.D., had requested them from Tim Pearce at the Carnegie Museum of Natural History, Pittsburgh. Tim brought the slugs to D.C. last weekend and then left them in my care.

PickledPhilomycus2

The entire lot weighed about 7 kilograms or 15 pounds on the bathroom scale. Now, Megan and I are trying to figure out a plan for a smooth transfer of these alcoholic Nacktschnecken, or naked snails, to her.

PickledPhilomycus3

There are also several slides of genitalia removed from dissected slugs. The person who prepared these slides more than a decade ago apparently mounted them in something called Permount. The mountant has since been yellowing and turning opaque. Soon, the genitalia will all be totally obscured.

PickledPhilomycus4

Before I relinquish the slugs to Megan, I will try to examine and photograph some of the dissections.

03 May 2009

American Oystercatcher on Courtney Campbell Causeway

oystercatcher

On our last day in Florida last month we were driving on Courtney Campbell Causeway across the Tampa Bay when I spotted this bird. Because I was on the slower side road with plenty of parking, I could stop quickly. I jumped out of the car, grabbed the camera from the back seat, ran to the rocks and took this shot. Unfortunately, the 35 mm macro lens happened to be on the camera. Then I ran back to the car, put the 40-150 mm lens on, ran back to the rocks, but the bird was gone.

If I'm not mistaken it is an American oystercatcher.

New leaves on the poison ivy

PoisonIvy2

01 May 2009

Yellow nail polish put to good use

I don't think I have ever seen a woman with yellow nails, but a coworker in my office claimed she had used it when I asked her if there was such a thing as yellow nail polish. Later I did find yellow nail polish, not just one, but at least 2 brands, in a store. This was before my trip to Florida last month. But no, it was not for my nails.

I wanted to do some field experiments to determine the dispersal rates and patterns of the intertidal snail Batillaria minima I was planning to study. These snails have black shells. So I figured yellow nail polish would be the best marker for them. Here are some snails that I marked at low tide when they were exposed on rocks.

YellowBatillaria1

And here are a couple of them among some unmarked ones 2 days later.

YellowBatillaria2

The nail polish I used turned out to be quite stable even when exposed to sea water. I was able to locate marked snails up to 4 days later—the last day I looked for them.