30 September 2008

Lucky to be a supercentenarian

While discussing the role of chance in the making of scientific discoveries in this post, I noted that chance events play a part in almost everything we do in our lives. Yesterday, I was reading a news article by Mitch Leslie in last Friday's Science that was about the supercentenarians (people who are 110 or older) and the scientists who are studying them.

So far, it appears that the supercentenarians have varying genetic makeups and lifestyles, but, as noted by one of the researchers, they all share one factor that contributed to their longevity: luck.

Calment* provides a prime example. She outlived her husband, daughter, and grandson. They died from non-aging-related causes—the husband from food poisoning, the daughter from pneumonia, and the grandson in a car accident. So if you hope to reach the big 110, keep a rabbit’s foot handy.

*Jeanne Louise Calment, who died in 1997 at the age of 122. She is the oldest person to have lived whose age could be verified.

29 September 2008

Greek Houses of Foça: still standing after all these years

Turkey once had a substantial population of Greeks. During its final decades, especially after the Balkan Wars, the Ottoman Empire initiated an exchange policy that sent many Anatolian Greeks to Greece in return for the Moslems in Greece and the Balkans. This policy reached its climax in 1922 in the hands of the new Turkish Republic who had emerged victoriously from the Greco-Turkish War and all native Greeks of Turkey except those in a few cities and islands were forced to migrate permanently to Greece.

The buildings left behind by the hastily leaving Greeks still linger on in many places in Turkey. Over at Snapshots from Nemo Ramjet, there are 3 pictures of deserted Greek houses in the Cappadocia region of Turkey. Cappadocia was once a cultural center of the Anatolian Greeks who wrote Turkish, their native language, using Greek letters. This was known as Karamanlica.

Nemo Ramjet's post reminded me of the Greek houses that I had photographed in the summer of 2006 near Foça (ancient Phocaea or Phokaia) in western Turkey.

FocaGreekHouse1

Foça also had a sizable Greek population that left the area before or after the Greco-Turkish War1.

FocaGreekHouse2

Some of the Greek houses within Foça have been renovated in recent years and are currently in use. The buildings pictured here are out in the countryside along the road between Foça and Yeni Foça (New Foça) to the north.

FocaGreekHouse3

Segments of the houses, for example, this window, also provide glimpses of the construction techniques of a bygone era.

FocaGreekHouse4

1According to a Turkish book I have (Sıtkı Aydınel. 1993. Kuva-yı Milliye Harekatı. Kültür Bakanlığı, Ankara.), by 1917 the non-Moslem population of Foça was down to zero from ~9000 in 1894. The book attributes this drastic decline in population of non-Moslems during the intervening years to the population exchanges that took place after the Balkan Wars. However, I am not entirely comfortable about the reliability or the neutrality of the author of the book. Elsewhere in the book he mentions that at the start of the Greco-Turkish War there was a Greek garrison in Foça, implying that the town may have been one of their entry points to Turkey, the main one being Izmir to the south. This raises the question of whether the Greek army would have picked a town as its beachhead if there were no local Greeks there to provide them with support and supplies.

28 September 2008

Flattened fauna of sidewalks - Part 2

We start with a beetle of some sort. It looks like the aftermath of a collision with an automobile. I tried to identify it from pictures in the few insects books I have and also from the pictures on BugGuide.net, but gave up. If anyone can put a name on it, I will appreciate it.

FlatFauna5

The next victim is a desiccated earthworm that obviously lingered on the sidewalk too long after the sun came out and then it was too late to reach the safety of the wet soil. It is now ant food.

FlatFauna6

Next we have quite a mess. It looks like a cricket missing its head with body parts all over the place. Was it hit by a car, attacked by a predator, stepped on by a human? We will never know.

FlatFauna7

Part 1 was here.

To be continued...

26 September 2008

Beveridge's beverage or the role of chance in scientific discoveries

William Ian Beardmore Beveridge (1908-2006) was an Australian veterinarian with a long, distinguished career1. Besides many papers and books on veterinary medicine, he also wrote 2 books on how scientists work and how scientific discoveries are made.

The 1st book, The Art of Scientific Investigation, was published in 1950, followed by a revised edition in 1957. The 2nd book, Seeds of Discovery, came out in 1980. It is one of my all-time favorite books. I've had a copy since 1982 and still pick it up every now and then and re-read parts of it.

Recently, I bought a cheap ex-library copy of The Art of Scientific Investigation (2nd ed.) and started reading it. It is basically a compilation of mostly anecdotal accounts of how various scientists worked and made their discoveries. Beveridge put a great emphasis on the significance of chance in science.

Probably the majority of discoveries in biology and medicine have been come upon unexpectedly, or at least had an element of chance in them, especially the most important and revolutionary ones.
I am not sure if that's true. Also, one can argue that everything everyone does has an element of chance in it. In retrospect, the schools we've been to, the people we've met, the things we've done were all predetermined by chance events to some extend. So, it's not surprising that chance plays a part also in scientific discoveries.

Nevertheless, Beveridge was careful to point out that not every lucky scientist ends up with a groundbreaking discovery.
The role of chance is merely to provide the opportunity and the scientist has to recognize it and grasp it.
This, of course, remind us of a saying attributed to Louis Pasteur: "In the field of observation, chance favors only the prepared mind." This is indeed true. If a scientist's mind is not always ready to grasp the significance of an unusual observation or an unexpected experimental result, then chance will favor someone else.

Beveridge's beverage! (I just like saying that).

1Fenner, F. 2007. William Ian Beardmore Beveridge. 1908-2006. Australian Veterinary Journal, 85:1-2.

One lost, one found

Lost&Found

Signs from the neighborhood.

25 September 2008

Is it a slug? Is it a ghost? It's Selenochlamys ysbryda

ResearchBlogging.org
B. ROWSON & W. 0. C. SYMONDSON (2008). Selenochlamys ysbryda sp. nov. from Wales, UK: a Testacella-like slug new to western Europe (Stylommatophora: Trigonochlamydidae) Journal of Conchology, 39, 537-552

Back in July, the discovery of a bizarre carnivorous slug in Wales was in the news. The formal description of Selenochlamys ysbryda got published in the June issue of the Journal of Conchology that I received a couple of days ago and read this morning.


Selenochlamys ysbryda. Picture from National Museum Wales.

Selenochlamys ysbryda is a long (up to 110 mm) and narrow (up to 10 mm wide) colorless to milk white slug with a tiny (~2 mm long) internal vestigial shell near its rear end. It has a "very small" mantle covering its rear end. What about its lung?
Pulmonary cavity sunken below mantle, its volume difficult to establish, and without obvious venation.
How on earth does it absorb the oxygen from the air it breathes? Perhaps, oxygen just diffuses in thru the walls of the organs and the heart, which is described as "large", and carbon dioxide diffuses out.

Like its shell, the eyes of S. ysbryda are also small and vestigial. And the slug is nocturnal. Captive individuals of S. ysbryda were apparently eating live earthworms, although the authors never actually saw a slug in the process of doing so. However, they note that "earthworms regularly disappeared from the containers, and faeces appeared every 2-6 days...They contained numerous sigmoid earthworm chaetae."


Selenochlamys ysbryda going after earthworms. The red arrow (my addition) points at the vestigial shell. Fig. 7 from Rowson & Symondson.

The species name ysbryda means "a ghost or spirit" in Welsh. This is how the authors explain the name:
The name alludes to the species' ghostly appearance, nocturnal, predatory behaviour and the element of mystery surrounding its origin.
The provenance of the slug is indeed a mystery. Its type location is given as an "urban domestic garden" in Cardiff, Wales in the United Kingdom. However, the genus Selenochlamys have previously been known only from a few museum specimens coming from the western Caucasus of Georgia, southern Russia and the adjacent parts of Turkey. The authors speculate that in the wild S. ysbryda may live deep in the soil. This implies that the slugs may have been dispersed by humans in soil and plants.

24 September 2008

Lepidopterous insects of September

The 1st one was easy to identify. It's a Pandora Sphinx (Eumorpha pandorus). I photographed it about a week ago on the wall of a pedestrian tunnel that goes under the railroad tracks in College Park, Maryland.

PandoraSphinx

The next one is one of the confounded skippers photographed recently in the park near my house. I am guessing that it's a Sachem (Atalopedes campestris). I have submitted the pictures to BugGuide.net and will hopefully get a confirmation or another ID.

Sachem2

Here is a view from above.

Sachem1

Note added 3 hours later: The identification of the skipper a female Sachem has been confirmed on BugGuide.net.

23 September 2008

Oxford English Dictionary predates me!

In this post from April 2007, I complained how the respectable Journal of Molluscan Studies had let the authors of a paper they published "mistakenly" use the verb predate to mean "to prey on."

Imagine my frustration earlier today when I heard on the last week's edition of the BBC's Best of Natural History Radio podcast the narrator Philippa Forrester say "the whole idea of a bat predating migrant birds might come off as a bit of a shock..."

I decided it was time for another blog post. But then I thought it would be good to have the backing of perhaps the ultimate authority on these matters, the Oxford English Dictionary. So, I quickly e-mailed Deniz, who has access to the on-line version of the OED (which I, incidentally, once snubbed in this post), and asked her to look up predate for me. She quickly sent me the entry from the OED.

Now imagine my utter surprise, when I read the definition #2 of predate as a verb:

predate
verb
2

[Either < classical Latin praed{amac}t-, past participial stem (see -ATE suffix3) of praed{amac}r{imac} to plunder, spoil (see PREAD v.) after PREDATION n., or back-formation < PREDATION n. Compare PREDATISM n., PREDATIVE adj.]

1. trans. To act as a predator of; to catch and eat (prey). Chiefly in pass.

1941 [implied in PREDATED adj.]. 1956 Proc. Royal Soc. B. 145 313 Many larvae..were heavily predated by cuckoos. 1977 New Scientist 27 Oct. 220/3 The eggs of many species of frogs are predated by many species of vertebrates and invertebrates. 1994 Nature Conservancy May-June 18/2 People, who scare turtles, also bring litter, which..also brings more raccoons to predate nests. 2002 J. COHEN & I. STEWART Evolving Alien vii. 154 These could then be grazed by specialised protozoa (ciliates like Paramecium..), which were then predated by larger organisms.

2. intr. To act as a predator.

1974 Trout & Salmon Mar. 50/2 It is hoped that the stock of trout will predate sufficiently to minimise the problem [of coarse fish]. 1977 Field 13 Jan. 47/1 Man is a predator... To predate in person, instead of by proxy, is not unnatural. 1995 Daily Tel. 12 Aug. (Weekend Suppl.) 3/4 An awful lot of things use dead wood... They eat it, hide in it or use it to predate on dead wood invertebrates.
Well, there you have it folks. I was wrong all along. If the OED says it's okay, who am I to argue that it's not?

Let the predators predate their prey from now on.

22 September 2008

Megapallifera galore

MegapalliferaGalore

This is one of the "slug holes" I have been monitoring since 2006. It is a narrow cavity in a beech tree in the park near my house. There is always water on the bottom. During the day slugs huddle at the far end of the cavity taking advantage of the high humidity. At night they come out of the hole and climb up the tree to feed on the microscopic algae that grow on the trunk.

These are a Megapallifera species that I have not yet identified below the genus level (family Philomycidae). They are native to the area. I have written about them before.

This picture was taken last Thursday afternoon. Once when I checked this hole in December, the water inside was frozen and, not surprisingly, there were no slugs. I intend to check this hole and a few others in the vicinity at weekly intervals this fall to determine when the slugs disappear. I believe they spend the winter deep in the ground.

Watch this blog for updates.

21 September 2008

Oh, frass!

Over at a snail's eye view, Snail says "We should celebrate chewed leaves." Over here, we are celebrating what chewed leaves, in this particular case, chewed tomato leaves, turn into: frass, that is, insect shit.

Yesterday afternoon, I noticed this group of little black pellets on the deck below an overhanging tomato plant.

frass

They turned out to be the frass of 2 tomato hornworms, caterpillars of the five-spotted hawk moth (Manduca quinquemaculata).

TobaccoHormworm6

And here is the frass end of one of the caterpillars.

TobaccoHormworm7

The caterpillars have been gorging themselves on the leaves of the tomato plant. That is okay, for the plant has passed its prime, although it still has one little green tomato left, which I am hoping will turn red before it gets too cold.

This time I am also hoping the caterpillars will escape the fate that befell their less fortunate kin last year, braconid wasps. I want to witness them going thru their metamorphosis.

An occasion for a clinquant celebration

After a relatively slow Friday, yesterday's visitor counts went thru the ceiling. That was because World Wide Words put a link in their 20 September newsletter to this recent post of mine featuring a sentence of weird words.

visitors20sep

New visitors are still coming today. How you doing, folks?

Obviously, what I need to do to attract more readers to this blog is to use weird words more often. I think that's a copacetic idea!

20 September 2008

Is this what the future holds for me?


Speed Bump by Dave Coverly

19 September 2008

How a glaring error of mine was corrected a year later

Back in August 2007 I wrote this post about mating slugs. Yesterday it came to my attention that someone on flickr was using a portion of that post (with a link to my blog) to illustrate a great picture of mating Arion.

I send the link to the picture to some friends. A few hours later, one of them, Tim Pearce, responded with his "peer review":

The description says "... and spermathecas are exchanged." Ouch! The spermatheca is part of the anatomy. The description probably meant spermatophores are exchanged.
Ouch indeed! It was, of course, my mistake and no other reader, including myself, had noticed it until Tim saw it.

I quickly corrected my post and then notified the photographer of the picture on flickr. The caption on flickr has since been corrected also.

The spermatheca (also called the bursa copulatrix) is an organ that can't be exchanged, while a spermatophore is a packet of sperm that is given to a slug's (or a snail's) partner during mating and may or may not be stored in the spermatheca. I often confuse the 2 terms, spermatheca and spermatophore. I think I will be more careful about their proper usage from now on.

18 September 2008

Paper on Pherbellia albovaria, the snail-killing fly is out

In this post and also in this post, I wrote about a dead fly I had found in a container of land snail shells. The fly was eventually identified as Pherbellia albovaria (Diptera: Sciomyzidae). The larvae of sciomyzids are snail predators.

A note I wrote about that fly just came out in issue #18 of Triton. You may download a pdf copy from here.

Triton is the journal of the Israel Malacological Society. It is published twice a year, usually around March and October. More information is available here.

17 September 2008

It's the population growth, stupid

The Orion magazine has an on-line interview with James Gustave "Gus" Speth, the dean of the Yale School of Forestry and Environmental Studies. They talk about Mr. Speth’s new book The Bridge at the Edge of the World. I haven't read Mr. Speth's book, but his opinions put forward during the interview neither impressed nor convinced me enough to consider joining the "grassroots citizens’ movement" he is advocating to help save planet Earth.

If I understood him correctly, Mr. Speth is claiming that capitalism has been at the root of our growing environmental problems.

What [capitalism] really cares about is profits and growth, and the rest is more or less incidental. And until we change that system, my conclusion is that it will continue to be fundamentally destructive.
I agree with him on that. But the ultimate cause of ecological degradation, human population growth, is getting sidetracked again. Mr. Speth is heading down the wrong track when he can make a statement like this with a straight face:
But the scale of the impact is really derived from the phenomenal amount of economic growth in rich countries, not from the phenomenal population growth.
Even in scientific discussions of conservation biology the problem of human population growth gets swept under the rug. This was the point I tried to make in this recent post. But is is especially discouraging to hear from an environmentalist that population growth does not have an impact.

I also see a curious contradiction of premises. On the one hand, Mr. Speth is claiming that the developing countries "need to grow," but on the other hand, he seems to be blaming capitalism for many social problems of developed countries, including loneliness and bipolar disorders. Is he saying that the developing countries need capitalistic development now so that they can have their share of problems later?

If Mr. Speth is spearheading a revolution, you can count me out (in).

I also posted these comments in a slightly different and shorter form after the interview at the Orion site (comment #72).

16 September 2008

Squirrel teeth marks on bone

One day last week I let my cat out into the backyard and a few seconds later followed her. As soon as I stepped on the deck, I heard the chirp-like sounds eastern gray squirrels (Sciurus carolinensis) seem to make when they spot a predator, in this case, probably the cat. I looked up at the nearby pine tree and saw a squirrel jumping from one branch to another and, at the same time, noticed a large white object falling to the ground.

It turned out to be the pelvic bone of a deer. No, the squirrel hadn't dragged a deer up the tree for dinner; it was one of the many deer bones that we had once collected in the nearby woods and now are scattered throughout our yard.

DeerPelvis

The close examination of the bone solved a mystery that I had first written about in this post: who's been gnawing on our deer bones? The pelvic bone had numerous distinct scratch marks along its edges. These are probably the squirrel's teeth marks.

BoneGnawedBySquirrel1

So the squirrels are the bone eaters. But, why do they do that? A quick look at The Encyclopedia of Mammals (David Macdonald, ed., 1984) suggested one possible answer. As in other rodents (for example, beavers), squirrels' incisor teeth grow continuously. So they have to keep chewing on hard objects, nuts and the like, to wear their teeth down lest they get too long to fit into their mouths.

Another possibility that I can think of is that squirrels satisfy their calcium requirement by gnawing on bones.

Here is another detail from the same bone.

BoneGnawedBySquirrel2

15 September 2008

How to mark a snail shell - Part 2

In this post back in August, I explained how I marked the shells of a land snail, a Triodopsis species, by filing small notches into the lips of the shells. The total number of shells I marked and released was 14.

Last week, almost a month later, I went back to the same spot and collected 18 snails, all I could find. 10 of the snails had notches in their lips. Surprisingly, only 4 of the snails had partially repaired the notches; in the rest of the snails, the notches filed into their lips were still, well, notches. Moreover, in those snails that attempted to repair the notches, the notch itself remained but only the inner side—where the snail's body is—was closed. Apparently, the snail can't fill the notch.

Here is a photograph of one "repaired" notch (arrow). The remnants of green paint is from April when I had marked this particular snail and a few others with a green pen (that story is here).

TriodopsisRepaired

So it looks like filing notches into their lips is a good way to mark these snails. Even if a snail repairs its lip, the mark remains visible and it is easily detected in the field. My next trip to the study site will be in November when the snails will be winding down for the winter.

Part 3

14 September 2008

Sometimes we have to let nature run its course

Over at Bug Safari, Cindy writes that she found a giant swallowtail with a damaged wing that couldn't fly and that she repaired it with a "spare" butterfly wing she had. Apparently, the operation went well and the butterfly regained the ability to fly. Amazing!

Despite Cindy's good intentions, I have mixed feelings about interfering with natural processes. I don't object to rescuing birds and other animals from oil spills or treating animals injured by other types of human activities, but we have to draw the line somewhere. Injury and death caused by natural events are natural processes.

Should we be treating every animal that escaped with injuries from the jaws of a predator or a wind storm or a flood? We neither have a responsibility nor a right to do so. Natural selection doesn't need us to interfere with its affairs.

Sometimes we need to step aside, move away and just be impartial observers.

Sentimentality does not exist in nature.
Karl von Frisch, The dancing bees, 1953
Incidentally, I am surprised that Cindy's butterfly couldn't fly when she first found it, because, as far as I can tell from the picture, its damaged wing didn't look too bad. I have seen butterflies with more damaged wings that could still fly. Here is an example of a butterfly with severely damaged wings and here is an example of a butterfly with a minor damage to one wing.

13 September 2008

A thelemic gallimaufry for this pulchritudinous nychthemeron

Yesterday morning Deniz sent a link to this list of weird words. I liked them so much that I challenged her (and myself) to write a sentence using as many words as one can from that list. Here is my sentence (the words from the list are in italics):

It was a sennight ago during an evening of plenilune, when a rebarbative slubberdegullion, looking more like a gaberlunzie carrying deep inside a gossypiboma impregnated with empasm but nevertheless smelling of petrichore, made his foudroyant entrance into the anfractuosity of the vomitorium where the acronychal wayzgoose was taking place while introducing himself, with frequent cachinnatory interruptions one would expect from a gelotologist being subjected to gargalesis, as a cruciverbalist creator of semordnilaps that can be viewed with a smaragdine zograscope and soon, however, was floccinaucinihilipilificated in the minds of the coulrophobic blatherskite deipnosophists and bloviating ergophobic dracontologists around him on account of the mattoid impression that he was only a tergiversating ultracrepidarian suffering from either lippitude or triskaidekaphobia and when vellicated—while fletcherising everything sapid and esculent within his reach and grozing on his wine glass—obnubilated his intentions further by not being able to perform his dactylonomy to figure out the zenzizenzizenzic of 2 without an isabelline anthropodermic volvelle.
Deniz's sentence is here.

12 September 2008

The red-eyed fly among us: Drosophila melanogaster

ResearchBlogging.org
Andreas Keller (2007). Drosophila melanogaster's history as a human commensal Current Biology 17: R77-R81.


While looking thru the old numbers of Current Biology, I found this interesting essay (pdf) on the fruit fly Drosophila melanogaster and its close association with humans.

Drosophila melanogaster and its 8 sister species form the Drosophila melanogaster group. All but 2 have so far been found only in the tropical Africa and are believed to be endemic there. This implies that the remaining 2 species, D. melanogaster and D. simulans, which are cosmopolitan, also originated from the same region of Africa.

Like the house mouse Mus musculus, D. melanogaster owes its present worldwide distribution to its attachment to humans. Unlike the mouse, however, D. melanogaster appears to be a relatively late comer. It was 1st recorded in North America in New York in 1875. Nevertheless, the fly's spread in northeast U.S. was quick and by 1915 it had arrived acrosss the continent in California.


(Fig. 3 from Keller, 2007.)

Keller doesn't mention when D. simulans was introduced into North America.

All species in the Drosophila melanogaster group breed on fruits. In addition, D. melanogaster has been bred from foods it is unlikely to encounter in its ancestral home in Africa, such as canned fruits, cider mill refuse, raspberry vinegar, tomatoes and potatoes.

DrosophilaMelanogaster
I found this one wet in my bathroom sink. I took it outside and while it was drying itself, photographed it. It is probably Drosophila melanogaster.

Besides being more catholic in their food preferences, what other factors may have contributed to the successful infiltration of human societies by D. melanogaster and D. simulans? Keller mentions their short generation spans and the capacity to produce lots of offspring and tendency to enter human settlements. The latter undoubtedly helps them survive cold weather.

I think there are also the factors that prevent D. melanogaster from turning into a pest: they are small, they don't bite and they don't seem to spread any human diseases. Consequently, they either go unnoticed or ignored and tolerated.

11 September 2008

Simplicity comes at a cost

To reduce is the skill of masters.
Deng Ming-Dao, Everyday Tao, 1996
Most afternoons on the way home from work, I ride in the same subway car with some guy—in fact, we always enter thru the same door. Although this has been going on for about 2 years now, we don’t know each other and we’ve exchanged but a few words once or twice.

This fellow comes with his bike. Soon after I started seeing him, I noticed that his bike didn’t have brake levers on the handlebars; nor was there anything resembling a brake on the wheels. Recently, when I paid a little closer attention to his bike, I realized that it didn’t have gears either. There is just a chainring in the front turning via the chain a single cog in the back.

A few days later, I commented to him about his bike. His response was as simple as his now-disclosed intention: “There is less maintenance without brakes and gears.”

I inquired further: “How do you stop, then?”

“I don’t go fast.”

I can not blame him for not wanting to be bothered with bicycle maintenance and repair. But there are trade-offs associated with my fellow subway rider’s bicycling simplicity. He can’t ride his bike fast or down a hill. Nor can he ride it up a steep hill unless he has powerful leg muscles to forgo the need for gears. His travels on his simple bike are limited to slow rides on flat roads.

How do we achieve simplicity without sacrificing not so much the conveniences but the opportunities of complexity?

10 September 2008

Digital image processing: to crop or not to crop?

This all started when I left a comment on ant photographer extraordinaire Alex Wild's Myrmecos Blog to note that a large starting image file is good when one needs to crop the image so that enough pixels will be left to print a decent-sized final image at 300 dpi. Alex responded with this post, to explain that cropping should not be used to increase "magnification"; better image quality would be obtained by taking a more magnified picture either by moving closer to the object or by using a better lens. I agree with him wholeheartedly.

But sometimes cropping is a good thing. Here is a picture of the land snail Helix aspersa (= Cornu aspersum). This is the original uncropped image.

HelixUncropped

When I took this picture the snail was in my left hand and the camera in my right hand. Perhaps I should have moved in a little bit closer with the camera, but I didn't want to leave out any part, especially the tentacles, of the snail, which was continuously moving its head around, and at the same time, I wanted to include my fingers as a scale. So when I sold this picture to a photo agency, I cropped out quite a bit of the background. Here is the final image that will be printed in a biology textbook.

HelixCropped

At 300 dpi, its dimensions were 16.6x13 cm (6.5x5.1 inches). I doubt they will print it that large; they may crop it some more or reduce the size. In this case, if I had moved in closer, I would have cropped less, but I doubt the final image quality would have been noticeably better.

On the other hand, if you are photographing something long and narrow, like a this slug Limax maximus, and if you want to include the entire animal in the picture there is a limit to how close you can get to it. In that case, you must crop.

Here is the uncropped image of the slug.

LimaxUncropped

I could have approached it a little bit more, but not much, especially if it had had its tentacles out. The extra spaces on top and on the bottom are inevitable. So, if I wanted to print this picture in an article, I would do quite a bit of cropping.

LimaxCropped

Because I took the original with my 8 MB Olympus E-500, the cropped image retained enough pixels for a 21.7x5.6 cm (8.6x2.2 inches) print at 300 dpi. This is when megapixel cameras are indispensable.

Cropping a poor image won't make it better, but cropping a good image can improve it. Therefore, the rule of thumb is: if it's crap, don't crop.

09 September 2008

Flattened fauna of sidewalks

There is a book out there called Flattened Fauna by Roger Knutson that intends to be a guide to the countless hapless animals—mostly vertebrates, I suppose (I didn't read the book)—killed on roads. Here is my guide to the flattened invertebrates of sidewalks.

FlatFauna1

This is a slug. The patterns visible on its skin tell me that it is a Limax maximus.

FlatFauna2

Another slug. This one was being processed into ant food. I am not sure what species it is. A careful microscopic examination of the remains might have identified the genus, but I didn't think the information gained would have been worth the effort.

FlatFauna3

A grasshopper or a katydid. I think it was a grasshopper.

FlatFauna4

I have no idea what this was. It too had ants on it, so it must have been another yummy treat.

Part 2 is here.

08 September 2008

Cultured coconut milk, eh?

This is something new I picked up at the Whole Foods Market on Saturday. Apparently it is made by fermenting coconut milk with the usual yogurt bacteria, Lactobacillus bulgaricus, Streptoccus thermophilus and the like. I don't quite know what I am supposed to be calling it, though. So Delicious? How original is that? "Do you have So Delicious cultured coconut milk?" Is that what I am expected to say to a shopkeeper? They could and should have come up with a better one-word brand name.

CulturedCoconutMilk

I saw several varieties of flavors, but decided to try the plain to get a better feeling for the intrinsic flavor of cultured coconut milk. It had a custard-like consistency and a mild but noticeable coconut flavor. And luckily, it wasn't too sweet. I enjoyed it.

Unfortunately, however, in terms of nutrition, from one 170-gram cup of cultured coconut milk you only get carbohydrates (16 g) and fat (7 g) and essentially nothing else. The amount of protein (1 g) is insignificant. In comparison, an equal weight cup of nonfat yogurt gives me 15 grams of protein; enough to keep me going from breakfast until lunch.

So Delicious cultured coconut milk would be an enjoyable dessert once in a while. But it's not something I would want to have in place of my yogurt.

07 September 2008

Giant African snail, Achatina fulica, a potential predator of gastropods

Back in July, Christopher Taylor over at Catalogue of Organisms had a post about snails in which he casually mentioned that the giant African snail Achatina fulica was a predator of invertebrates. "What?" I exclaimed upon reading that, "This ludicrous error must be corrected!" and quickly left a comment on Christopher's post to indicate that Achatina fulica was a dreaded plant pest with the implication that it was unlikely to be a predator of invertebrates.

Imagine my surprise and embarrassment when the March issue of the American Malacological Bulletin arrived early in August (because I had become a member only a few months earlier) to present, among other interesting articles, a short note titled "Giant African snail, Achatina fulica, as a snail predator"1.

The paper reports that individuals of A. fulica have been observed consuming the slug Veronicella cubensis in Hawaii. On one occasion the authors offered a live slug to 3 juvenile A. fulica with the following results:

All three A. fulica climbed on top of the slug and proceeded to consume the integument of the slug. It took over five minutes for the snails to kill the slug. During the first three minutes, the slug crawled and pulled the snails with it as it moved. In the last two minutes, the slug seemed distressed and tried to curl up. After the slug stopped moving, the snails continued to consume the slug for a few minutes.
According to the authors, carnivorous behavior by A. fulica has not been reported before.

Achatina fulica is an introduced species in Hawaii and many other places. It is considered a serious plant pest in areas where it is not native (more info from the USDA). Now we know that introduced populations of A. fulica may threaten not only agricultural and native plants but possibly also native gastropod species.

I have one criticism for the subject paper. Since A. fulica was observed eating slugs not snails, the title of the paper should have been "Giant African snail, Achatina fulica, as a slug predator".


1Meyer, W.M., Hayes, K.A. & Meyer, A.L. (2008). Giant African snail, Achatina fulica, as a snail predator. American Malacological Bulletin 24:117-119.

05 September 2008

So many phyla so little time to eat them all

In response to yesterday's post about my lifelong goal to see at least one live member of each animal phylum, Tim Pearce sent an e-mail to remind me about his goal to eat one species of every phylum. His rules are: "it has to be intentional and verifiable, but needn’t be the whole animal".

Coming from Tim, that's a shuddering thought, for he otherwise claims to be a vegetarian!

Tim says he has so far eaten from the following animal phyla: Porifera, Cnidaria, Ctenophora, Platyhelminthes, Nematoda, Nematomorpha, Rotifera, Tardigrada, Sipunculida, Bryozoa, Ectoprocta, Brachiopoda, Mollusca, Annelida, Arthropoda, Chordata and Echinodermata.

I forgot to ask him what the tardigrade tasted like.

As for me, I have intentionally eaten only from the Chordata (who hasn't?), Mollusca, Arthropoda and Echinodermata. The latter was the ovary of a sea urchin eaten raw right out of the poor animal that was still alive.

If I am ever offered a nematomorph to eat, I will pass the plate. Thank you.

04 September 2008

So many phyla so little time

Which animal phylum consists of one and only one species? The Placozoa. And the only species in that phylum is the simplest animal of them all, Trichoplax adhaerens.

I have never seen a Trichoplax, which is a rather small (1-2 mm) creature. But I have seen members of smaller phyla, such as rotifers. So size is not a reason why I have not seen a Trichoplax. In fact, some other phyla that have members much larger than Trichoplax are among those phyla that I have so far not had the pleasure of getting acquainted with. What are those phyla?

But, first, I need to figure out how many animal phyla there are. However, that is not an as easy task as it seems. Wikipedia lists 36, the Animal Diversity Web lists 32 and the University of California Museum of Paleontology gives 25 extant animal phyla.

There are some significant differences between these disparate lists. For example, the ADW list includes the Myxozoa, whereas the other 2 lists don't; the UCMP list unites the rotifers and the acanthocephalans, while the Wikipedia list keeps them separate. It is really pointless to attempt to consolidate them or to argue that one is better than the other.

Instead, I will list a compilation of some of the phyla of which I have yet to see a live member: Acanthocephala, Chaetognatha, Gnathostomulida, Hemichordata, Nematomorpha, Nemertea, Onychophora, Priapulida, Sipuncula, Echiura, Phoronida, Loricifera, Pogonophora, Brachiopoda, Placozoa and so on.

I may have seen a kinorhynch once while looking at a marine sediment sample under a microscope, but I lost the animal—whatever it was—after a brief glance at it. Also, I am not sure if I have seen bryozoans.

I would like to see at least one live member of all animal phyla before I die.

Follow-up post: How many phyla have you eaten?

Boxcar mini-graffiti LXVII, LXVIII, LXIX & LXX

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Boxcar graffiti LXV & LXVI

03 September 2008

Fences in wildlife reserves may be dangerous to wild cats

ResearchBlogging.org
Moayyad Sher Shah, Peter Cunningham (2008). Fences as a threat to Sand Cats, Felis margarita Loche, 1858, in Saudi Arabia. Zoology in the Middle East, 44: 104-106

Sand cats (Felis margarita) are in danger of getting trapped while attempting to force themselves to go thru metal fences in a wildlife reserve in Saudi Arabia. Since 2003, Shah & Cunningham found 2 dead and 2 live sand cats all of which had their heads stuck in a diamond mesh fence that was erected in 2003 to keep livestock out of a plant protection area within the larger Saja/Umm Ar-Rimth Protected Area in central Saudi Arabia.

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An adult sand cat with head stuck in fence. This animal was subsequently rescued and released. Photograph from Shah & Cunningham (2008).

Three of the stuck cats were sexed and determined to be females. The authors think that the male cats may have larger heads that may be less likely to fit into the openings of fences. They recommend regular patrols along fences in wildlife reserves to free any trapped cats.

02 September 2008

Parade of cicada exuviae

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I saw these exuviae* of cicadas last nite underneath one of the branches of a large pine tree I have in my backyard.

I don't know what species they are. I photographed a live cicada about a week ago in College Park, which may have been the same species as these. I posted its pictures on BugGuide.net a couple of days later, but no one has so far come up with an identification.


*I am confused about this word. Exuviae is a plural; for example, Merriam-Webster, defines it as "sloughed off natural animal coverings", but doesn't give a singular form of the word. Yet Gullan & Cranston (The Insects, An Outline of Entomology, 2005) have this statement in the caption of Fig. 10.2: "adult [mosquito] emerging from its pupal exuviae at the water surface". And the picture shows one mosquito that must have had one covering.

01 September 2008

Happy Laboratory Day!

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From A Guide to Elementary Chemistry for Beginners By Le Roy Clark Cooley (1886).