28 February 2007

The sublimely bad Abdülhamid

Note: Some of the characters in this post may not display properly unless the encoding of your browser is set to Unicode (UTF-8).

Since last October, a new abnormal interest of mine has been the Arabic script that had been used to write Turkish for several centuries until 1928 when it was replaced by the present alphabet of Latin characters.

The Arabic script was never quite suited for Turkish. For one thing, Turkish had 8 vowel sounds (now represented by a, e, u, ü, o, ö, i and ı—the undotted i), whereas Arabic had only 3. To make up for this deficiency, the Arabic letter waw1 (و) had been inconveniently adopted to represent either one of the vowels u, ü, o, ö, in addition to the consonant v. Which sound waw actually represented in a particular word was usually left to the reader to figure out from the context. Besides, many words had standard spellings that one had to learn to recognize by sight. As one can imagine, it was difficult to learn to read and write Turkish written in the Arabic script.

The January 2007 issue of the Turkish history magazine Toplumsal Tarih mentions one incident2 from the reign (1876-1909) of the Ottoman sultan Abdülhamid II that arose directly from the unsuitability of the Arabic script to write Turkish. Abdülhamid was arguably the most despotic, oppressive and paranoid Ottoman sultan. Under his policies, newspapers and magazines were heavily censored, many were closed down; writers and publishers were often jailed or exiled.

According to Toplumsal Tarih, during that period the newspaper Sabah once printed an article that intended to refer to the sultan, using his customary title, as şevketlü Abdülhamid3 (sublime Abdülhamid). Şevketlü would have been written as sevketlü2 with the Arabic letters representing (from right to left) ş, v, k, t, l, ü, while the missing vowels, e, e, were added by the reader. That was the standard spelling of şevketlü. Note that the first waw (from the right) stands for v, while the last one for ü. The letter marked with an arrow is lam that represented the sound of l.

During the printing of the Sabah, however, the lam was, presumably inadvertently, dropped. Unfortunately for the publishers, the remaining letters, ş, v, k, t, ü, did not represent the standard spelling of any word and so, what word(s) they may have meant was open to interpretation. One possible reading Abdülhamid's men came up with was obtained when the first waw represented not the v sound, but the vowel u, while an ö was added between k and t. These substitutions produced the phrase şu kötü Abdülhamid, meaning "that bad Abdülhamid".

Sure enough, the Sabah was ordered to cease publication.

abdülhamit
The despotic Ottoman sultan Abdülhamid II (1842-1918). His big nose was a source of humor (behind his back, of course).


1In Turkish vav, because there is no w sound.
2The original source of the story is somewhat anectodal as it was taken from a contemporary writer's memoirs.
3The Turkish letter ş has the sound of sh, while ü is pronounced as in German.

27 February 2007

Can animals predict earthquakes?

An interesting article by Matt Kaplan in the 17 February of the New Scientist is about the millennia old claims that many animals, including, dogs, snakes, elephants, can sense an earthquake sometimes days before it strikes.

Animals have frequently been claimed to demonstrate unusual behaviors prior to earthquakes, including agitation and attempts to escape, if they were captive. Apparently in China, according to the article, they now even keep and monitor snakes for strange behaviors in hopes of predicting earthquakes.

One problem with all the existing claims is that they have all been anecdotal and when more scientific data are taken into consideration, nothing concrete emerges. For example, the article mentions that some villagers in Thailand told the story that on 26 December 2004 their buffalo that had been grazing on a beach had gotten agitated and headed for a nearby hill minutes before the devastating tsunami came (the villagers who followed the buffalo survived). But at the same time in Sri Lanka, a WWF scientist who was monitoring the movements of radio-collared elephants did not notice any unusual activity in one herd that was 100 m away from a beach before the tsunami arrived. All the elephants did was move behind a sand dune after they saw the tsunami approaching.

Animals' quake-predicting abilities will become more respectable only if someone can predict an earthquake using animal behavior well-before the earthquake happens; post-predictions do not count. The inherent difficulty associated with predicting earthquakes stems from the fact that an earthquake is a complex event that results from the interactions of a large number of factors. This was summarized by Geller et al.1 as follows:

Whether any particular small earthquake grows into a large earthquake depends on a myriad of fine details of physical conditions throughout a large volume, not just in the immediate vicinity of the fault. This highly sensitive nonlinear dependence of earthquake rupture on unknown initial conditions severely limits predictability. The prediction of individual large earthquakes would require the unlikely capability of knowing all of these details with great accuracy. [citations omitted]

Along these lines, the New Scientist notes that "the activity associated with different earthquakes is highly variable". That being the case, I don't see much hope for the reliable use of animals to predict earthquakes.


1Geller et al. 1997. Earthquakes cannot be predicted. Science 275:1616.

Boxcar graffiti XLVII & XLVIII

boxcar47


boxcar48

26 February 2007

Let them disperse

Some noteworthy ideas derived from a paper by Bilton et al.1 on the dispersal of freshwater invertebrates.

The authors define dispersal as "the movement of individuals or propagules between spatially (or temporally) discrete localities or populations". It is somewhat redundant in its wording, for an individual that disperses is a propagule and there is no need to specify that dispersal is to be between "populations".

What are the advantages of dispersal? It reduces competition, which matters if resources are limited, lowers the chances of inbreeding (in sexually reproducing animals) and of encountering predators and parasites. In other words, dispersal provides an escape mechanism from density-dependent adverse events. One other advantage of dispersal that the paper neglects to emphasize is that for those organisms that live in ephemeral habitats, dispersal may provide a significant long-term survival mechanism and the only route to the colonization of new ephemeral habitats.

Dispersal results in gene flow and, consequently, reduced genetic differentiation between colonies.

Dispersal can be active or passive. Active dispersal requires the ability to fly or crawl between habitats and, of course, means to detect a suitable habitat from a distance. Wandering around blindly would most likely end in the death of the wanderer. Passive dispersal may be done while being attached to the body of a larger and more mobile animal. The technical term for this type of hitchhiking is phoresy.

phoreticmites
Freshwater larvae in the act of phoresy while attached to a water beetle. When the beetles move from one habitat to another, they inadvertently disperse the mites, which are actually parasitic. Photos from Bilton et al.

Blowing around in the wind is another potential mechanism of passive dispersal. But, its outcome may not be too different than that of wandering around blindly. The authors question "the reliability of dispersing by wind to suitable freshwater habitats owing to the high likelihood of terrestrial deposition".

Dormant stages of passive dispersers usually have reduced metabolic rates and increased tolerance to desiccation and temperature extremes. These traits enable them to survive in the absence of water. Did such traits originally evolve as adaptations for dispersal? I suspect that the dormant stages may have first appeared as adaptations for in situ survival of temporary dry conditions.

The paper also discusses some apparent cases of evolutionary trade-offs between dispersal and reproductive performance in aquatic insects. Among the several examples presented, one is about water boatmen (Sigara spp.), in which individuals without flight muscles (those who, therefore, cannot disperse) have higher fecundity (more egg production). Likewise, in some water beetles the flight muscles autolyse after reproduction starts. Despite, or perhaps, because of such trade-offs, populations are variable in their dispersal ability.

In addition to spatial dispersal, some freshwater invertebrates have dispersal in time, or temporal dispersal. Temporal dispersal takes place when dormant propagules of a species accumulate in its habitat, forming "propagule banks", and are activated at different times in the future. Some dormant zooplankton eggs have been claimed to remain alive for more than 200 years. According to the paper, temporal dispersal may benefit predominantly clonal or inbred organisms by introducing genes from the past, so to speak. I suspect that propagules also function as reservoirs of individuals to recolonize their habitat if and after an environmental catastrophe destroys all the active individuals.

The authors note that "despite our longstanding appreciation that freshwater organisms achieve dispersal, the extent and mode of dispersal remain poorly understood."

Some of my past posts on dispersal of snails:

Darwin’s snails

Flying mollusks

Flying clausiliids

It was raining mussels and clams


1Bilton, Freeland & Okamura. 2001. Dispersal in freshwater invertebrates. Ann Rev. Ecol. Syst. 32:159-81.

Definitely not a snowman

notasnowman

24 February 2007

Amateurish cartography

When it comes to cartography, I am an amateur. (Come to think of it, I am an amateur when it comes to a lot of other things.) I do like the subject of making and understanding maps, though. And I have a few old cartography books. One of them is Erwin Raisz's General Cartography from 1948 that I bought at a used book sale for 2 bucks some time ago.

raisz

Lacking many of the sophisticated specialized devices of cartography, such as the one for drawing guidelines Raisz mentions, I invariably resort to Photoshop when I need a map for a manuscript or a presentation.

letteringdevice

For an upcoming presentation, I need a map of Turkey with a grid of latitudes and longitudes. There are many such maps that I can simply scan and use, but for my purposes, the background map needs to be blank and the grid needs to be on a separate layer. To create a map like that-in my amateur way—it is necessary to scan a suitable map and then retrace the outlines of Turkey as well as the latitudes and longitudes on separate layers in Photoshop. That is exactly what I did last nite, spending several hours for one map. But when I did a test print, I realized that 2 of the longitudes, the 36th and the 42nd (red arrows), were misplaced. There really was no easy way to correct the map, because the problem was with the way I had to scan the base map, which was bound in a book and could not be scanned flat.

TRgrid

Later tonite I am going back to the drawing table to burn more midnite oil.

drawintabl

23 February 2007

Is it a fly or a wasp?


Fusco Brothers by J.C. Duffy

Wasps have 2 pairs of wings. Therefore, the fairy flies are wasps (order Hymenoptera).



Flies have 1 pair of wings. Therefore, the bee flies are flies (order Diptera), even though bees are hymenopterans.

Both drawings and information are from How to know the insects by H. E. Jaques (1947).

22 February 2007

Evolution of jaw asymmetry in snail-eating snakes

Southeast Asian snakes in the subfamily Pareatinae prey mostly on terrestrial snails and slugs. But their jaws are not strong enough to crush snail shells. So, instead, they grab the snail's body and pull it out of its shell. A new study by Hoso et al.1 demonstrates that snail-eating pareatine snakes have more teeth on their right jaws than on the left and attribute this difference to the prevalence of dextrally coiled (right-handed) shells in snails.


The snake Pareas iwasakii, from Japan, comes from behind following the snail's mucus track, grabs the snail's foot and then pulls the snail's body out of its shell with alternate retractions of its left and right jaws. The snail used in the experiments was Bradybaena similaris. Photographs from Hoso et al.1.

The study found that the snail predator Pareas iwasakii had an average of 17.5 teeth on its left jaw and 24.9 teeth on its right jaw (n = 28). A similar asymmetry was demonstrated in the jaws of one unhatched snake, implying that the trait has a genetic basis. Furthermore, the teeth numbers on the jaws were asymmetric in 12 out of 14 pareatine species. One of the remaining 2 species feeds on lizards in addition to snails, while the other one feeds exclusively on slugs.


The jaws (stained with alizarin red) of one specimen of P. iwasakii with 16 left and 24 right teeth. Photograph from Hoso et al.1.

In the feeding tests Hoso et al. conducted using dextral and sinistral (left-handed) individuals of the snail Bradybaena similaris, P. iwasakii required significantly longer handling time with sinistral snails than with dextrals and failed to extract sinistral snails more frequently than dextrals.

According to the phylogeny of these snakes (cited in the paper), the ancestral snakes had symmetric dentition, which suggests that the unequal teeth numbers on the snake's jaws is an adaptation to preying on dextral snails. The snails, on the other hand, may not have been marching in place. Hoso et al. speculate that the wide diversity of sinistral land snails in Southeast Asia may have resulted from selective pressure the snakes have been putting on dextral snails; if dextral snails are more likely to get eaten, then natural selection will naturally select for sinistral variants.


Appreciations are due to the good folks at CONCH-L for bringing this paper to my attention.


1Masaki Hoso, Takahiro Asami, Michio Hori. Right-handed snakes: convergent evolution of asymmetry for functional specialization. Biology Letters. DOI: 10.1098/rsbl.2006.0600

21 February 2007

What is Dixie English anyway?

My Linguistic Profile:
55% General American English
25% Yankee
10% Dixie
0% Midwestern
0% Upper Midwestern

The moment one species becomes two


A diagrammatic representation of speciation (metapopulation
lineage divergence). Even if every taxonomist using a different species definition based on different properties (SC1 thru SC8) agreed that originally there was one species that subsequently evolved to become two, there would necessarily be disagreement about the number of species present in the gray zones. Drawing from de Queiroz1.

According to Kevin de Queiroz1, during the period of the Modern Evolutionary Synthesis species (including those that are asexual) "were equated with groups of interconnected populations [metapopulations] that form an extended reproductive community and an unevenly distributed but unitary gene pool or field for gene recombination". Moreover, as de Queiroz points out, even in descriptions of species as lineages, the general metapopulation concept of species was implied.

de Queiroz adopts this notion and proposes that the only necessary defining property of species is that they are separately evolving metapopulation lineages. All other properties that have previously been attributed to species (SC1 thru SC8 in the drawing above), for example, reproductive isolation, or the occupancy of a distinct niche, become properties that species as metapopulation lineages may or may not acquire. In de Queiroz’s words:

...metapopulation lineages do not have to be phenetically distinguishable, or diagnosable, or monophyletic, or reproductively isolated, or ecologically divergent, to be species. They only have to be evolving separately from other such lineages.

It is not clear to me, however, how de Queiroz’s proposal, which otherwise makes perfect sense, would pinpoint the moment of appearance of two species from one if we really cared to do so (see the drawing above). This is, of course, not a new issue and was discussed a while ago by Ernst Mayr2:

...the two daughter species are virtually identical at the moment of the split, and if any species differences evolve in the two separated lines, it is by gradual transformation. This makes it impossible to designate a precise point of origin of the new daughter species.


1Kevin de Queiroz. Ernst Mayr and the modern concept of species. PNAS 2005 102:6600-6607. pdf
2 Ernst Mayr. 1989. Toward a New Philosophy of Biology. (p. 325).

20 February 2007

19 February 2007

How I determined this was Hawaiia minuscula

hminuscula
The pictured shell was 1.8 mm in diameter.

Hawaiia minuscula is a widespread land snail in the U.S. My specimens came from Monocacy Natural Resources Area in Frederick County, Maryland. Its small, more or less flat and mostly smooth shell with a wide umbilicus make H. minuscula easy to recognize until one realizes that there is another species, Lucilla inermis1, whose shell is almost identical to that of H. minuscula. According to Pilsbry2 the shells of the species in the subgenus Hebetodiscus "resemble Hawaiia minuscula somewhat, but are smoother and more depressed". I think the resemblance is a bit stronger than "somewhat", for after I examined the drawings in Pilsbry, I had no idea how tell if the shells I had were minuscula or inermis.

Then, I noticed in Pilsbry that there was a tiny difference between the anatomies of Hawaiia and Hebetodiscus: the latter has one retractor on its penis and another one on its epiphallus, while the former has a retractor only on its penis. Luckily, I had 2 alcohol specimens. So I dissected them. Now, if these were large snails, it would be quite easy to find their genitalia, but the snails I dissected were barely 1.6 mm across and what was worse was that they were apparently not adults; their genitalia were nowhere to be found.

As I was about to give up, Tim Pearce came to the rescue and pointed out that the teeth on the radulae of H. minuscula and L. inermis have different shapes, the most significant being the shapes of the marginal teeth, blade-like in minuscula but serrated in inermis (see the drawings below).


The teeth of Lucilla inermis (left) and Hawaiia minuscula (right). Notice the different shapes of the marginal teeth (#7 for inermis and #6 for minuscula). Drawings from Pilsbry.

No sooner did I read Tim's e-mail, than I set to work. I removed the radula of one of my specimens, transferred to a slide and put it under the microscope. The marginal teeth were blade-like (see photo below). I had H. minuscula.

minuscularadula
Flattened radula of Hawaiia minuscula from Monocacy Natural Resources Area. The capital M marks the column of median teeth; the red arrows point at the blade-like marginal teeth.

But, now there is another puzzle. Frank C. Baker3 gave the "most common" habitat of H. minuscula in Illinois as "woodlands of oak, hickory and sycamore". All of my specimens also came from leaf litter samples from woods. In contrast, this is what Hubricht4 said about H. minuscula: "A species of bare ground. I have never found it in leaf litter." Interestingly, he lists similar habitats for inermis: "open, grassy situations..." Go figure.


1I've been told that Helicodiscus (Hebetodiscus) singleyanus inermis (H.B. Baker, 1929) is now Lucilla inermis.
2Pilsbry, H.A. 1948. Land Mollusca of North America . Volume 2, parts 1 & 2.
3Baker, F.C. 1939. Fieldbook of Illinois Land Snails. p. 72.
4Hubricht, L. 1985. The distributions of the native land mollusks of eastern United States. Fieldiana #24.

17 February 2007

16 February 2007

A contractile snail

lycaonicaWhen I found this snail, a Chondrula lycaonica from Turkey, in its container, the snail's body was about one and ¾ of a whorl behind the aperture. I wasn't sure if it was still alive. So after I took its picture, I put in a shallow dish of water. Some time later, the snail came out.

The picture evinces that this snail's shell is oversized, that is, it has much more than enough space to contain its body.



This topic was the subject of several previous posts:

Spacious shells
Spacious shells 2
Spacious shells 3
Lots of Liguus
A snail at the edge: Littoraria irrorata
Withdraw or die!

Temi & her shadow

Temi&shadow

15 February 2007

An occasional male ostracod

Ostracods are microscopic crustaceans with a pair of carapaces resembling clam shells. Until recently no males had been seen—at least since about the end of the 19th century—in darwinuloid ostracods (family Darwinulidae) and they were assumed not to exist. In fact, a paper I reviewed briefly (Martens et al., 2003), claimed that darwinuloids had been reproducing asexually for about 200 million years.

A paper by Smith et al.1 that came out in June 2006, and which I just had a chance to read, however, reported the finding of males in a new species of darwinuloid ostracod, Vestalenula cornelia, from Japan. The paper also showed that male carapace morphology of the new species was similar to that of juvenile females. This implies that the conclusions of previous studies that sexed fossil ostracod carapaces from their morphology (for example, Martens et al., 2003) may have been flawed.


Anatomy of Vestalenula cornelia (with right valve removed and only one pair of appendages drawn for clarity). Female (top) and male (bottom). The latter is identified by its penis (Hp) in the back. Figure from Smith et al.1

Interestingly, only 3 males, in contrast to more than 600 females, of the new ostracod species were collected. Smith et al. offer the following possibilities to explain the rarity of males:

1. Certain environmental or seasonal factors may induce the production of male V. cornelia. This is supported by the fact that all 3 males were collected during late winter and early spring.

2. Males may be non-functional relicts that occasionally appear but have no reproductive input.

3. Males may be rare but nevertheless, functional, that is contributing to the genetic diversity of their populations.

With the removal of ostracods from the list, bdelloid rotifers remain to be the largest group of animals in which no males have ever been recorded.


1Robin J. Smith, Takahiro Kamiya, David J. Horne. 2006. Living males of the 'ancient asexual' Darwinulidae (Ostracoda: Crustacea). Proceedings of the Royal Society B: Biological Sciences 273:1569-1578.

14 February 2007

Love darts for you my love

helixaspersadarts

What could better express a malacologist's love on Valentine's Day than a box of love darts painstakingly isolated from scores of Helix aspersa* sacrificed in the name of love (and science)?

During mating of hermaphrodite land snails, each partner places a spermatophore, a bag of spermatozoa (sperm cells), in their partner's bursa copulatrix (BC). The spermatophore is digested in the BC and only a small fraction of the spermatozoa escapes to the higher parts of the female reproductive system to fertilize the partner's eggs.


Diagrammatic representation of the reproductive organs of a pulmonate snail. All pulmonates are hermaphrodites, but not all of them have darts. P, penis; D, dart; S, dart sac; V, vagina; MG, mucus glands; BC, bursa copulatrix; G, genital opening. Original by Koene, copy from Schilthuizen.

The so-called love darts are sharp needles of calcium carbonate that are stored one at a time in a special bag-like organ, the dart sac, and thrust inside the body of a snail's partner during mating. Studies have demonstrated that darts transfer mucus from the mucus glands (MG), which, probably by reducing sperm digestion in the BC, increases fertilization success of the sperm.


*Also known as Cantareus aspersus.

Recent papers on love darts:
Schilthuizen, M. 2005. The darting game in snails and slugs. TRENDS in Ecology and Evolution 20:581-584.
Joris M. Koene & Satoshi Chiba. 2006. The Way of the Samurai Snail. American Naturalist 168:553-555. copy and movie on Koene's web page

13 February 2007

12 February 2007

Deer skeleton

deerskltn

The weekend's most exciting discovery was a deer skeleton by a small creek not too far from my house. From the condition of the skeleton it appeared that the deer had died sometime in the fall. There were clumps of fur on the ground; the vertebrae were still attached to each other and the ribs were sticking up; the skull was partially covered by a dried piece of skin.

deerskul

Rarely do I come across a deer skull complete with bottom jaws. This particular specimen, with the bottom jaws still attached, would make a nice addition to my collection. But the removal of the skin stuck to the top of the skull and any other tissue remains that may be on the inside would require a major—and stinky—cleaning operation that I don't intend to undertake.

I will check up on it occasionally. Perhaps I will have a chance to recover the skull intact once it is a bit cleaner.

10 February 2007

Anguispira alternata angulata

MNRAangulata
Anguispira alternata angulata from MNRA. Both shells were from an area about 40 m X 10 m.

One of the abundant species in Monocacy Natural Resources Area where I did a land snail survey was what Pilsbry1 called Anguispira alternata angulata, a keeled or carinated morph of Anguispira alternata. According to Pilsbry's synonymy, this morph was first described by Férussac in 1822 as Helix alternata var. carinata. In 1896, Pilsbry & Rhoads changed the name to Pyramidula alternata carinata and then in 1948, Pilsbry came up with the new name Anguispira alternata form angulata.


Figure from Pilsbry1.

According to Pilsbry1, the shell of angulata differs from the typical A. alternata "by the distinctly to strongly angular periphery". Although he makes the point that the periphery is "hardly to be called keeled", to me "carinated", "angular" and "keeled" all mean more or less the same thing, especially when the degree of carination is variable.

Pilsbry also notes that the prominent ribs on the upper surface of the shell "are much reduced (or sometimes subobsolete)" below the periphery, that is on the bottom of the shell. Leaving aside the question of what he might have possibly meant by "subobsolete", I will point out that the prominence of the ribs on the bottom of my shells are indeed quite variable even in specimens collected from the same location. For example, the photo below shows the bottoms of the 2 shells from MNRA shown in the first picture. The one on the left in the first picture is the one on the bottom in the picture below. Its bottom is smoother than that of the other shell. And these shells were from an area about 40 m X 10 m. So speculating that there may have been differences in their habitats is not justified in this case. I don't know if shell size is a factor that contributes to shell sculpture (the shell with the smoother bottom is smaller).

MRNAangulatabttm
Bottoms of the shells in the first photo. The one on the left in the first picture is the one on the bottom here.

Pilsbry gave records of angulata from several eastern states including, Kentucky, Pennsylvania, Tennessee, Virginia and Maryland. Earlier, F. C. Baker2 had noted that in several counties of Illinois "a form of Anguispira alternata occurs which has a carinated periphery and a low spire...It is not so abundant as the typical form. In the southern part of Illinois there is a tendency for the shell of alternata to become carinated on the periphery, even when the spire is high". The drawing on the left, from Baker, shows A. a. alternata (A) and A. a. angulata (B).

It appears that A. a. angulata is a widespread morph whose exact relationship with A. a. alternata is not yet clear. Angulata is also the dominant, if not the only morph of Anguispira alternata, in wooded lots along the Maryland side of the Potomac River at least up to Harpers Ferry in West Virginia from where Pilsbry gives a record. (There is also Anguispira fergusoni, which is indeed a separate and easy to distinguish species.) I have several alcohol specimens of angulata collected during my survey of MNRA. Their internal anatomy—if and when I get a chance to dissect them—will hopefully offer some clues as to whether A. a. angulata is distinct enough to be considered a separate taxon.


1Pilsbry, H.A. 1948. Land Mollusca of North America . Volume 2, part 2, p. 573.
2Baker, F.C. 1939. Fieldbook of Illinois Land Snails. p. 85.

09 February 2007

It's about time...

It's been more than 3 years now since I finished surveying the land snails of a hunting reserve, the Monocacy Natural Resources Area, along the Monocacy River in Frederick County, Maryland. The reserve, about 2 km X 1 km in extent, is a mostly wooded, hilly property watered by several creeks that drain into the Monocacy river that flows alongside the reserve.


The large river is the Monocacy. Map from TopoZone

MNRA was a nice place to survey with lots of snails and was rarely visited by the public, except during the hunting season in the winter when I, naturally, avoided the area. I had made so many trips there during the 2.5 years the survey took that towards the end I had become quite familiar with the topography; I knew where the all trails went and had located the easiest places to cross the creeks.

shelldeskI now have 3 big boxes full of snail shells and about 80 lots of alcohol specimens. I haven't had time to figure out the identities of the problematic taxa, especially, the ever-abundant "Glyphyalinia" specimens and the native philomycid slugs. So, the manuscript that I should have been writing, which I want to write, has been delayed. Every now and then, someone from the Maryland DNR, who gave me the permit to do the survey, contacts me to inquire about the results, which then reminds me that I should hurry up and publish what I found.

So a couple of weeks ago I went back to the 3 big boxes full of snail shells and started going thru them one bag at a time. I am confirming my previous identifications or identifying for the first time some of the specimens collected during my last trips. At the same time I am building a database on the computer. The next step will be the dissections.

Tomorrow I will post about one of the problematic species.

08 February 2007

Basteria, vol. 70. Nos. 4-6

The latest issue of Basteria, the scientific journal of the Netherlands Malacological Society (or is the Dutch Malacological Society?), arrived in yesterday's mail. As usual, there are several interesting articles that kept me busy in the train during today's commute to and from work.

One article, by Verdcourt, describes 2 new taxa of land snails from Madagascar. One of them is Kalidos dupuyi with a relatively large (diameter: 28.5 mm) shell of 7.5 whorls. The picture below from Verdcourt's article shows 2 individuals mating. This is the typical mating position of land snails with wide shells. The arrow (my addition) is pointing at what was probably the penis of one of the snails.


Although I usually don't pay much attention to papers on marine snails, the one by Garilli & Galletti on Cerithium lividulum and C. renovatum from the Mediterranean was quite informative. The shells of these 2 species are apparently quite variable and difficult to tell apart from their teleoconch (adult shell) sculptures. However, the SEM photographs in the paper show that the protoconchs (larval shells) of the 2 species are distinct from each other.

Another paper on marine snails, this one by Rolán & Hernández, describes several species from Mauritania and Senegal. The interesting thing about them is that some are tiny: the holotype of one species, Eatonina ordofasciarum (picture below), is only 1.0 mm high. Miniaturization in snails was the topic of some old posts of mine here and here.


The holotype (7) and 2 paratypes (8, 9) of Eatonina ordofasciarum.

Among the other articles there is one about a giant squid that was captured in the North Sea, another one about a new land snail species, Lindbergia garganoensis, from Italy that marks the first record of the genus outside of Greece and also a short note by Gittenberger & Menkhorst that provides some nomenclatural clarifications for 3 species of enid land snails (family Enidae) of Turkey.

07 February 2007

Measures of endemism

For about a month now, I have been compiling a list of the land snails endemic to Turkey. A taxon (for example, a species, a genus or a family) is endemic to a particular area if it occurs only in that area. My next step and the ultimate aim is to determine if there are any centers of land snail endemism in Turkey. A center of endemism could be defined as an area where there many more endemic species than there are in adjacent areas of equal size. So to determine if an area is a center of endemism, one needs an objective way of counting endemic species.

An internet search yielded the full text of quite an informative paper1 titled "Endemism in the Australian flora". I have no specific interest in the flora of Australia, other than reading the relevant posts on A Snail's Eye View, but I figured the theory and methodology used in this paper would be as applicable to snails as they were to plants.

The authors mapped the distributions of 8468 plant species on a map of Australia using a grid of 1° latitude X 1° longitude. The resulting map (Fig. 1 in the paper) immediately gives one an idea of where the endemic species are concentrated. (One complaint I have: the color codes used in the maps are not explained in the paper unless I missed it, but from the context it appears that yellows and reds are for low numbers of species, the blues are for intermediate numbers, while the reddish colors are for the highest numbers of species.)

Three ways of measuring endemism are discussed in the paper. One is a simple count of the number of endemics per grid cell. But the patterns of endemism are scale-dependent. The authors set an upper limit of 4 cells and calculate for each cell the total number of endemics whose ranges are 4 cells or less (Fig. 2 in the paper).

The second measure is the weighted endemism (WE), which is the sum of the reciprocal of the total number of cells each species in a grid cell is found in.

WE = ∑ 1/C (C is the number of grid cells each endemic occurs in)

What makes the paper really useful is the third and the a new measure of endemism it introduces, the corrected weighted endemism (CWE). The corrected weighted endemism is simply the weighted endemism divided by the total number of species in a cell.

CWE = WE/K (K is the total number of species in a grid cell)

These measures are discussed in detail on p. 186 of the paper. (The abbreviations used here are mine.)

Using one (or more) of these methods, a measure is calculated for each grid cell and indicated on a map. The comparisons of mapped CWE values gives a pretty accurate idea of where the centers of endemism are; it does at least for the Australian flora, according to the authors (Fig. 3 in the paper).

As I develop my database further and start analyzing it, there will be more posts on this subject.


1Crisp, M. D., Laffan, S., Linder, H. P., and Monro, A. 2001. Endemism in the Australian flora. Journal of Biogeography 28:183-198. pdf

06 February 2007

Frozen fluvial fluids

frozenLSC
Little Seneca Creek today early in the afternoon.

frozenLSC2

Miserably cold

This morning at 7:45, outside the back door the mercury, or, rather, the alcohol was at -14°C (~7 °F).

minus14

Yet right inside the glass door in the sun, the plant with the funny name, Doronicum Little Leo (Doronicum orientale), has put up a flower. First we thought it was a dandelion that had sneaked into the pot, but then I realized it was indeed a Doronicum flower. Doronicum is actually an outdoor plant and this particular one was out in the backyard until the end of last summer when it started to look like it was about to expire. I transplanted it into a pot and then when the weather started to get cold, brought it indoors. It has recovered nicely.

doronicum2

We have to think positive thoughts to stay warm on a day like this. If Doronicum is flowering, the spring must be around the corner.

05 February 2007

The 2nd law is holding up in the dead of the winter

What do steam engines and skunk cabbages have in common?

Whenever I am straining the limits of my mind to make sense out of thermodynamic abstractions about steam engines, those favorite machines of physical chemists, I think of the good ol' steam locomotives. I remember that they were still in use in Turkey when I was growing up in the early 1960s. It is not easy to forget a giant hulk of black steel entering a station with pistons going back and forth to turn the wheels and steam spewing out of the chimney with all sorts of huffing and puffing sounds while the heat not converted to work escaping into a cold sink to satisfy the 2nd law of thermodynamics.

As Peter Atkins explains elegantly in Galileo's Finger (figure below), a steam engine couldn't do any work if it didn't lose some of the energy generated by the boiling water as heat into a cold sink, which, in the case of a steam locomotive, is the surroundings, including the sweating fireman shoveling coal into the firebox.


The extraction of energy from the boiler of the steam locomotive decreases
its entropy. At the same time, the “wasted” energy heating up the locomotive itself, the air, the fireman and everything else nearby increases their entropy. As long as the net result is an increase in entropy, the 2nd law of thermodynamics is satisfied and the locomotive operates spontaneously.

The “burning” or oxidation of glucose, the fuel not only of skunk cabbages, but also of most other creatures under the sun, is not exempt from the 2nd law and it too produces lots of heat.

C6H12O6 (glucose) + 6O2 --> 6CO2 + 6H2O + heat

In cells, this process is coupled to a synthesis pathway, utilizing some of the liberated energy to make ATP (with about 40% efficiency) while the rest is released as heat into the surroundings, which is the cold sink. And that is exactly how compost piles get hot, our bodies stay warm in the winter and skunk cabbages produce heat.

The figure below, from a paper by Knutson1, shows the spadix (flower head) temperatures of skunk cabbages (Symplocarpus foetidus) at various air temperatures. Clearly, the skunk cabbages like it hot. Knutson also showed that the plants’ oxygen consumption was inversely related to air temperature. In other words, the colder the surrounding air got, the more starch (stored in their roots) the skunk cabbages were burning to stay warm. Starch breaks down into glucose, the oxidation of which produces both ATP and heat.


I wanted to witness the skunk cabbages in action with my own eyes. About 10 days ago after we had our first snow of the season, I went to the field where I had seen skunk cabbages in early bloom. Sure enough, the thermometer stuck into the spadix of one skunk cabbage went up to a little over 7 °C, while the temperature within the surrounding snow was 0 °C.

sktemp

Knutson’s figure predicts a much higher spadix temperature at an air temperature of 0 °C. Perhaps, a glass thermometer isn’t the most accurate way to measure the temperature of a skunk cabbage.

icetemp2

Steam locomotives passing by fields of skunk cabbages in the old days sure had something in common with them besides the fact that they could both smell funny.


1Knutson RM. 1974. Heat production and temperature regulation in eastern skunk cabbage. Science 186:746-7.

03 February 2007

Saturday nite's beer review: Monkey wrench

monkeyrench

Monkey Wrench is brewed by the Daleside Brewery located somewhere in England. The label on the bottle describes it as "dark and beautifully smooth" while according to the Daleside's web page, it is a "strong, smooth, malty ale with a touch of sweetness". It was smooth alright, whatever that means, but I wouldn't call it "strong" and I didn't think it was sweet at all. It is a good beer, nevertheless, but I would like it better if it had a stronger aroma.

Daleside has a peculiar, poorly written and designed web page. If you look under "Bottled beers", you won't find the Monkey Wrench, but if you Google for it, the link I put above comes up. Why is it that only seldom does a brewery have a decent webpage?

Cheers!

02 February 2007

Not so modern conchology, but fully digitized nevertheless

A recent post at A Snail’s Eye View was about the conchology book Edgar Allan Poe wrote, or rather plagiarized.

Hoping to find a digitized copy of Poe’s book, I searched Google Books, but came out empty handed. There are, however, a whole bunch of 19th century conchology books Google has scanned and most of which are undoubtedly more original than the one Poe put together.

I am providing a partial list only. If you want more, try searching Google Books for "full view books" using any combination of keywords that you might think would be relevant to conchology or malacology. One cautionary statement about Google Books: you will notice that they don’t seem to have a very good quality control system; occasionally there are missing, misplaced or poorly scanned pages.

General conchology; or, A description of shells, arranged according to the Linnean system. By William Wood. Published 1815.

The elements of modern conchology: briefly and plainly stated, for the use of students and travellers. By William Swainson. Published 1835.

Mollusca: Elements of conchology: prepared for the use of schools and colleges. Prepared by W.S.W. Ruschenberger from the text of Henri Milne-Edwards & Achille Comté. Published 1843.
Incidentally, this appears to be the scan of the personal copy of the American malacologist (conchologist?) Henry Hemphill. His name was stamped on some pages.


Natural history. Mollusca By Philip Henry Gosse. Published 1854.

The Complete Writings of Thomas Say, on the Conchology of the United States. By Thomas Say & William Greene Binney. Published 1858.

British conchology, or An account of the mollusca which now inhabit the British Isles and the surrounding seas. Vol. 1 Land and Freshwater shells. By John Gwyn Jeffreys. Published 1862.

A plain and easy account of the land and fresh-water mollusks of Great Britain. By Ralph Tate. Published 1866.

Structural and Systematic Conchology: An Introduction to the Study of the Mollusca. Vol. 1. By George Washington Tryon. Published 1882.

Happy downloading!

01 February 2007

Another oldie from the used book store

These days when I want to buy a specific book, I look for it on the Internet. I have all but stopped going to bookstores. The only bookstore that I go to is the one that sells used books at ridiculously cheap prices. It is a non-profit organization run by volunteers and their profits go to the public libraries in the county I live in. They get all the books the public libraries—and there are quite a number of them—don't want anymore as well as the books people donate. In fact, we buy books from them, read them and then donate them back to them.

Every trip there is an expedition so to speak, because you don't know what you will find. Some days there is nothing worth buying even if it is only a dollar, another day there may be a treasure on a bottom shelf like the 1954 copy of Tucker Abbott's American Seashells I got for $3 about a year ago. (Actually, the sticker on it said $4, but I told the lady it was too much and she took off $1.)

burch2

Anyway, today's find was John Burch's How to know the eastern land snails from 1962 along with 2 other books from the same How to know series, The immature insects from 1949 and The insects from 1947. The latter was the very first book published in the series.

Each book once belonged to the same person. They were next to each other on the shelf. The first one I removed was one of the insect books. I said to myself "I wish they had Burch's book" and removed the next one; it was the other insect book. I repeated "I wish they had Burch's book" and removed the 3rd one. It was my lucky day.

insects2

After I came home, I looked up Burch's book on Amazon. Someone is selling a used copy for $124.95!!! That's crazy. There is nothing in that book that would make it worth that much. I paid only $2 for it and I ain't selling it!