30 April 2008

Snail laying eggs

The reproductive behavior of the land snail Oxyloma retusa, already featured on this and this post, has become the research project of this spring. Infact, I will be presenting some results at the upcoming American Malacological Society meeting in Carbondale, Illinois at the end of June.

A few nights ago, one of the live snails I had appeared to be in death throes: it's body was swollen and bent in a peculiar way and the snail was motionless, although still alive. When I noticed that it's condition hadn't changed several minutes later, I was getting ready to drop it in alcohol. But I decided to take a look at it under the scope and that's when I noticed there was an egg sticking out of the side of its head; it was in throes of oviposition. Instead of the alcohol vial, it took the center stage on the photography table.

OxylomaOviposition

You can see the tip of the tail raised and the entire foot folded over itself; perhaps that position helps push the eggs out. It took the snail almost an hour to lay that cluster of eggs. After it was finished, it simply crawled away, leaving me in care of the eggs. Geez...


29 April 2008

A mild case of the bubonic plague poison ivy

PoisonIvy

This slightly gross looking and itchy bubo blister and the smaller ones around it appeared between the middle and ring fingers of my right hand over the last weekend. There is another cluster like that on the side of my right toe and a line of them on the lower surface of my left arm.

I must have brushed against some poison ivy during my recent trips to the C&O Canal (stories here and here). I do remember seeing, and ignoring, some small poison ivy plants while taking pictures. I have no idea how the poison (urushiol) of the poison ivy went thru my shoe and sock and ended up between my toes. Benadryl cream seems to help relieve the itching.

If the Black Death don't come knocking, I am expecting full recovery within a week or so.

I took the above picture while holding and operating the camera in my left hand. First, I didn't think I could do it, but it ended up being not too difficult.

Incidentally, according to this article, there were 13 human plague cases in the United States in 2006.


Our last hope

The very last surviving milkweed plant we had last August couldn't make it thru a dry period when we forgot to water it. And that was before it had produced any seed pods. With the demise of that plant, the long line of milkweed plants in our yard went extinct.

A week ago when we were cleaning the garage, we found a box full of envelopes with seeds of assorted plants that were saved and then forgotten. Among them were 2 envelopes labeled "milkweed seeds" and dated September 2000 and November 2004 and one unlabeled, undated envelope also containing the same.

MilkweedEnvelope

Over the past weekend, I planted all of the seeds in planters. I have no idea how long milkweed seeds survive under less than ideal conditions, but I am hoping that perhaps there was one live seed left in one of those envelopes that will bring back the milkweed lineage. The fingers are crossed.

MilkweedPlanting

28 April 2008

The weevil is in the details

C&Ocanal3

Before the rainy weather came, I was able to take my new trike to the C&O Canal one day over the weekend. At one point, I passed by this bright green "field" alonside the towpath; it was, of course, the canal itself. I stopped to investigate. It turned out that the water was densely covered with duckweed (Lemna sp.).

duckweed

While taking close-up shots of the duckweed, I noticed that there were numerous tiny things scampering across the surface. I had no idea what they were and so got even closer with the camera and took a few shots of them too.

TanysphyrusLemnae1

They turned out to be some sort of real tiny insects minding their own business in their 2 dimensional world of floating duckweed thalli and surface tension. I estimated that they were about 1 mm long. Soon after I posted their pictures on BugGuide.Net, the knowledgeable folks there identified them as Tanysphyrus lemnae, the duckweed weevil. And yes, they are the ones who were responsible for those holes in the duckweed.

Unless we stop once in a while and pay close attention to the world around us, we are bound to miss the microcosms of evolution that are there in the details. It's too unfortunate for us that we don't have enough hours in our days to spend more time to get closer to nature.


27 April 2008

Recycled toilet paper

toiletpaper
Seventh Generation toilet paper that is 100% recycled paper. Made in Canada!

You can now wipe your ass on paper that was once a love letter, the manuscript for a revolutionary idea in cosmology, a classified CIA document and pages from the _________ (enter the name of your favorite holy book).

Please flush the toilet when you are done.


Controlling pigs of Turkey

I wrote about the wild boar lunch I had in a village near Istanbul in this post. My chances of ever having a ham and cheese sandwich in Istanbul are, however, diminishing. The BBC reports that the governing Islamic AK Party of Turkey seems to be forcing the few remaining pig farms in Turkey to close and preventing the handful of Greek butchers serving the ever-dwindling Greek population of Istanbul from selling pig meat.

I have a tendency to take all news reports with a grain of salt, especially when they originate with "correspondents" whose accounts can't always be verified. But in this case, a Google search found many more reports in Turkish newspapers of the the government's ongoing attempts to close down the pig farms. Some of the news date back to 2005.


26 April 2008

Lock 26

Lock26

Lock 26 of the C&O Canal with a massive silver maple (Acer saccharinum) behind it.

SilverMaple

Mike High wrote about this tree in The C&O Canal Companion (1997).
An enormous maple tree stands next to the lockhouse ruins on the little island created by the flume, perhaps old enough to have been here when the Confederate wagons rolled past on their way to Antietam.


25 April 2008

We apologize for the incidental loss of life

Down where the invertebrates live, empty snail shells are popular places for nesting, hiding, egg-laying and even perhaps for just hanging out. In this post, I wrote about my observation of a thrips hiding in a snail shell.

I often find dead bees and flies in sealed bags of snail shells, sometimes months or years after they were collected. These are most likely the insects that hatched from eggs or cocoons that had been inside one of the shells. Because eggs and cocoons are usually located deep inside a shell, the collector may not always notice them, especially if the shell is opaque.

A few days ago, while looking at some bags of shells I had collected with Tim Pearce during a field trip we had in Virginia in November 2006, I saw this dead moth in one of the bags.

MothInShellBag1

I don't quite know why, but I always feel guilty when I find a dead insect in a bag of shells. Ironically, if I had intended to collect this moth, I would have felt less remorseful. In this case, however, all I wanted was the empty shells. My unintentional interference with the life cycle of this creature makes me regret that I collected the particular shell which it had selected as a safe haven for itself.

MothInShellBag2


24 April 2008

My new toy: Greenspeed Anura

Anura
After a month of deliberation, I bought an Anura, the delta trike made by Greenspeed of Australia.

Now there is no stopping me.


23 April 2008

A big millipede: Narceus americanus

Narceus1

Besides the rat snake, the only other animal I photographed during Tuesday’s Earth Day trip along the C&O Canal was this millipede Narceus americanus. There were also many butterflies around, but try as I did, I just couldn’t approach any of them for a good close-up.

Narceus2

These big millipedes were quite common on the towpath. I remember seeing them also during previous visits to the area. Unfortunately, large numbers of them get run over by bicycles. I am afraid I may also be guilty of at least one count of murder; for my defense, I can only say that it wasn’t premeditated. When there are so many things to look at along the path, it’s difficult to ride with one’s eyes fixed to the ground in front of the bike.

The toll of road crossings on invertebrate populations was the subject of this post. Of course, they are not the only ones who suffer on the roads. The New Scientist’s Environment blog reports that according to a recent study, amphibians made up 93% of all animal deaths on Indiana roads over a 16-month period.


Black rat snake in the wall

Nolands

I took the day off yesterday and went on a bike ride along the C&O Canal. It was a nice way to spend the Earth Day. One of the places I passed by was Nolands Ferry where the remains of this old wall is alongside the path.

SnakeInWall1

When I first saw this head sticking out of a gap between the blocks in the wall, I thought it was of a dead black rat snake* (Elaphe obsoleta). It was totally motionless when I approached it with my camera. After a few shots, I was getting ready to leave when I turned to take one last look and noticed that it had moved further into the gap. So it was alive. Then I saw its forked tongue flickering in and out of its mouth. Whenever I lifted the camera up to my eye, however, the tongue would disappear, only to return after I lowered it again. I was not to have a more exciting picture.

SnakeInWall2


*Identified by Butch Norden of the Maryland DNR.


22 April 2008

More on mating snails

It's spring time and my fancy turns to watching mating snails, specifically, Oxyloma retusa. I have written about their mating in this post. For the past week, I've been timing them while they do their thing.

experiment

Last night, I had 2 pairs under observation. One pair mated for 66 minutes, the other pair, the one on the tissue paper, for 95 minutes. The latter pair is the current record holder. I don't know why they need so much time. Does it really take that long to transfer sperm?

A couple of nights ago, I witnessed something even more interesting: 2 pairs mating simultaneously on top of each other.

MatingOxyloma2Pairs

I had seen simultaneous mating of more than one pair of snails once before with Rumina saharica. I suspect mating snails exude a pheromone-like chemical in their slimes that excites nearby snails, causing them to start mating also.


21 April 2008

Halide Edip Adıvar and the Armenians

Ever since Wikipedia linked to it, my review of the memoirs of the Turkish writer Halide Edip Adıvar (henceforth, Halide) has become one of my most often read posts. Yesterday, a reader left this comment at the said post: "HEA was a fascist manner [sic] neglecting the Armenocide 1915/16 with about one and a half million victims".

I will ignore the reader's absurd rhetoric that Halide was a fascist. Instead, I will respond to the claim that she neglected the Ottoman Armenians. First, I don't know what she was expected to have done with respect to the Armenians. She was primarily a writer and teacher and consequently, the positions she held in the Ottoman Government were along the lines of education and humanitarian work. Second, and quite contrary to the reader's claim, Halide was painfully aware of the happenings in Anatolia and wrote about them at every suitable occasion.

Let us read some passages from the 1st volume of her memoirs in Turkish, Mor Salkımlı Ev ("House with purple wisteria"; 1996 edition). In 1916 Halide was sent to Palestine and Lebanon to establish schools. At that time, the world was at war and the Ottomans were desperately trying to retain their rapidly weakening control over the Middle East. At Beersheba, she ran into an extraordinary nurse at a hospital. (All translations mine.)

Her round white face, despite the suffering and pain surrounding her, hadn't lost its freshness; her light brown eyes were radiating strongly and she was speaking a dialect of Turkish not unfamiliar to us. Her name was nurse Anna. She was a daughter of a Protestant Armenian family. The natural anger on both sides* arising from the mutual spilling of blood did not exist in her. In those days, it was not possible to come across an Armenian citizen who could see the deeper causes behind these catastrophies as much as she did.

*Presumably the Turks and the Armenians.
Later on, she worked at Ayin Tura, an orphanage (in Jerusalem?) where Turkish, Armenian and Kurdish children stayed. Apparently, Ayin Tura was in the habit of giving the Armenian children Moslem names so that they could be taken into the orphanage, which was otherwise strictly for Moslems.
I had long and difficult arguments with the late Cemal Pasha concerning the orphanage. I opposed to the practice of giving Turkish or Moslem names to the Armenian children.
Eventually, Halide appears to have been satisfied with the assurance given by Cemal Pasha, the Ottoman administrator, that no religious education was given in the orphanage and that the Armenian children were not being forced to become Moslem.

One day, 2 Kurdish children with bandages on their heads came to see her.
-We want permission to go to Damascus.
-Why do you want to go there?
-We will kill the Armenians.
-Why?
-Armenians killed our parents. The Armenian kids here are beating us everyday.
-Those who killed your parents were not the kids here. Besides, someone else killed their parents. Now tell me how you got injured on your heads.

They wouldn’t tell me. I sent them to the hospital. Two months later, the same children were working together and being friends with the Armenian kids at the weaving looms.
Halide wrote that only a few other incidents in her life had satisfied her as much as the work she had done at Ayin Tura.
After an especially favorite meal, the kids would sometimes break into singing a longing Anatolian song...The Armenian kids were especially talented in music and the band that they formed the majority of was a success story of which the orphanage was proud.
Halide also had Armenian friends. In Istanbul, one of them was the musician priest Komitas Vartabet (or Vartapet) (1869-1935). He used to give concerts at a cultural organization called the Türk Ocağı (Turkish Hearth).
...Komitas was a product of our country. For years, he had collected not only tunes of the old Gregorian music, but also Anatolian folk songs...Komitas would also come to my house and play and sing for hours. These visits continued even during the period when the Armenians and Turks were at each other's throats.
Halide notes that it was the Türk Ocağı that saved Komitas from getting exiled in 1915.

Obviously, my commenter has not read any of Halide's writings and is mostly ignorant of history. So now, let me give him/her a piece of my mind. If you want to criticize Halide Edip Adıvar, or anyone else, do it by all means. But, first, learn the facts and stick to them. And don’t come to this blog to spread half-baked ideas and hatred.


20 April 2008

How to create animate matter from seemingly lifeless dust

birdbath

This is no ordinary dust, though. It came from our birdbath that had been dry since last fall. I scraped off some of the crust of cyanobacteria (algae) from the bottom and placed the pieces in a small petri dish.

petridish

Then I added a little bit of water* to the dish and set it aside. An hour later, life had returned to it in the form of bdelloid rotifers. During the winter I had the birdbath turned upside down to prevent ice forming in it. Dry rotifers obviously survived in the crust. They didn’t mind the freezing temperatures either.

bdelloid6

Bdelloids share their ability to remain alive in a desiccated state with an odd assortment of other animals, including certain nematodes and tardigrades, some insect larvae and the brine shrimp Artemia. Desiccation survival (anhydrobiosis) probably evolved independently multiple times, because different protective mechanisms appear to be in operation in different animal groups. For example, nematodes, tardigrades and Artemia accumulate a disaccharide called trehalose prior to drying, whereas bdelloids don't (Lapinski & Tunnacliffe, 2003; Hengherr et al., 2008).

Previous posts about bdelloids: here, here and here.

*Tap water that had been filtered thru charcoal and heated to near boiling (to make coffee) and then cooled.

Steffen Hengherr, Arnd G. Heyer, Heinz-R. Köhler, Ralph O. Schill. 2008. Trehalose and anhydrobiosis in tardigrades - evidence for divergence in responses to dehydration. FEBS Journal 275:281–288. Abstract

Lapinski J, Tunnacliffe A. 2003. Anhydrobiosis without trehalose in bdelloid rotifers.
FEBS Letters 553:387-90.


18 April 2008

Pictures from high above 8: some place along the Potomac

PotomacFromAir2

I like to take pictures from airplane windows and then try to identify the landmarks in the pictures using Google Earth. I took this one last month on our way back from Florida as we were approaching the Washington National Airport from the south flying right above the Potomac River. The picture shows the eastern (Maryland) side of the Potomac.

I had no idea how far from the airport we were when I took the picture and because of that I wasn't too hopeful about locating the place in Google Earth. But, to my surprise, I found it quickly.

PotomacFromAir1
Picture from Google Earth. Turned 90° left to match its orientation with my photo ( North is to the left).

It looks like some sort of water treatment facility or sewer plant located off of Route 210 between Accokeek and Fort Washington. Maybe someone familiar with that area will eventually enlighten us as to the identity of the place.

PotomacFromAir3
Picture from Google Maps.

The picture from high above No. 7 was wind turbines in New York.


While nobody was looking...

The 3rd anniversary of Snail's Tales came and left. Next year I will try to remember it on the day it happens (April 9th). So let's postpone the party until then.

Happy anniversary to me anyway.


17 April 2008

Hell is in your imagination, Biggy

Graffiti3


It turns out there was a mouse behind it all

In My Life as an Explorer (1925), Sven Anders Hedin has an account of his visit to the monastery of Linga-gompa in Tibet in 1907.

In the interior, too, there was an air of mystery. I ascended a steep flight of steps into a Hall of divine images, where the light, from an opening on the left, with a shutter creaking in the wind, fell on a whole row of medium-sized Buddha figures. My companions had remained in an entrance-hall, and I was alone with the gods. Now and then a mouse ventured out of the dark, to feast on the contents of the offering-bowls on the altar-table.
(Previous posts about Hedin’s book are here and here and here and here.)


16 April 2008

What is a terrestrial animal?

If you think you know how to categorize animals as aquatic or terrestrial, think again. Are frogs aquatic or terrestrial? What about sea otters? And what about a human embryo floating in its amniotic fluid and breathing it into its lungs?

Strict definitions are not reliable, because there are always exceptions. Nevertheless, consider the following criteria, the best I can come up with so far, for aquatic and terrestrial animals.

A1. An aquatic animal spends its entire life cycle in a liquid medium that is mostly water.

A2. The volume of water making up the animal’s habitat is significantly larger than the body volume of the animal.


Conversely,

T1. A terrestrial animal spends its entire life cycle outside of water. If it enters the water to feed or for other activities, the total time spent in water is insignificant relative to the animal's life span.

T2. If there is an aqueous envelope around the animal, the envelope’s volume is significantly less than the body volume of the animal.


The problem is that if we go by these definitions, then there is no such thing as a terrestrial animal, because all animal embryos are surrounded by a watery medium and the volume of the medium is significantly larger than the body volume of the embryo at least during the early stages of its development. We need to modify the definition for terrestrial animals by adding a 3rd criterion.

T3. During the early stages of the animal's embryonic development, there may be an aqueous envelope around the embryo with a volume significantly larger than the body volume of the embryo if the egg or the parent’s body within which the embryo and the aqueous envelope are located are not themselves surrounded by a liquid medium.

Now the definitions are beginning to get cumbersome. It gets worse when we start considering those animals that fit into one set of criteria during one part of their lives and into the other one during the rest. For example, there are many snail species that live where the sea and the land meet. How do we decide if they are terrestrial snails or aquatic snails? Traditionally, those species that live outside the water and enter it only to reproduce have been classified as aquatic snails* (for example, Melampus bullaoides and Cerithidea scalariformis), while those that live and reproduce outside the water have been classified as land snails regardless of how close their habitats may be to the sea (for example, Truncatella species).

I have so far found only 3 relevant, but brief literature discussions of what it means to be terrestrial. The 1st one is by Labandeira & Beall (1990):

...we consider a "terrestrial organism" to be one that is obligately adapted to land; facultative behavioral adaptation of marine arthropods to a land-based existence is technically excluded...When both groups are discussed, we will refer to the first group as terrestrial and the last group as semiterrestrial. True terrestriality requires an obligate physiological commitment to life on land.
I don't find this a useful criterion, because it requires further explanation. What do they mean by "an obligate physiological commitment to life on land"?

The criterion used by Martens et al. (2004) to decide that the ostracods from forest leaf litter were terrestrial, however, agrees with mine. In response to another researcher, who did not consider similar ostracods to be terrestrial, this is what they said:
...did not consider his ostracods from terrestrial habitats themselves to be terrestrial, because these animals gather a film of moisture around and within their valves, so that they still breath through water. We reject this point of view, as nearly all forms of animal respiration, even that of humans, requires a degree of moisture, either externally or internally (within lungs). When animals live in terrestrial conditions, i.e. outside of free standing or flowing water, we consider them terrestrial.
Finally, here is Little's (1990) opinion:
If animals are effectively covered by a layer of water, then they are living as aquatic animals. If they are not so covered, which often means just that they are bigger, as earthworms are usually bigger than soil-dwelling nematodes, then they can be said to be truly terrestrial.
This criterion seem to introduce not a relative but an undefined absolute size criterion; in other words, very small animals can't be terrestrial. I don't find it convincing because of that reason.

A note of caution is necessary here. If we spend too much time thinking about such matters, we will be missing the point. Exercise is good for one's body and mind, an exercise in futility, on the other hand, is a waste of time. What matters is the characterization of the lifestyles of the animals of interest and the understanding of their evolutionary origins.


*If we applied the same reasoning to turtles, then there would be no such thing as a sea turtle, because they all lay their eggs on land.

Koen Martens, Patrick De Deckker & Giampaolo Rossetti. (2004). On a new terrestrial genus and species of Scottiinae (Crustacea, Ostracoda) from Australia, with a discussion on the phylogeny and the zoogeography of the subfamily,
Zoologischer Anzeiger, 243:21-36.

Labandeira, C. & Beall, B. S. (1990). Arthropod Terrestrialization. In
Arthropod Paleobiology, Short Courses in Paleontology No. 3: 214-232. Mikulic, D. & Culver, S. J. (Eds).

Little, C. (1990).
The Terrestrial Invasion. Cambridge University Press.


15 April 2008

Another yellow isopod: Porcellio scaber

I wrote about the yellow morphs of the common terrestrial isopod Armadillidium nasatum from my backyard. Last weekend, also in my backyard, I found a yellow Porcellio scaber, another relatively common isopod.

PorcellioSpinicornisYellow

The usual color of this species is gray. According to Hopkin (A Key to the Woodlice of Britain and Ireland, 1991), orange and cream morphs may be found, "especially near the sea". But I don't live near the sea.

What's behind the recent appearance of these yellow morphs in the backyard? Perhaps color morphs are periodically produced during the natural cycle these animals, although I have no idea what function they may serve.

Post revised 18 April 2008: In the original post I had identified this isopod as Porcellio spinicornis. Thankfully, both Joan Jass in Milwaukee and Ferenc Vilisics in Budapest e-mailed me to point out that the animal was actually P. scaber.


Food for wolves and vultures

No, I still haven’t finished Sven Anders Hedin’s My Life as an Explorer (1925) (previous posts about that book are here and here and here).

During Hedin’s expedition in Tibet in 1901, one of the Moslem men in his caravan died. After a night of vigil, the man was buried, prayers were recited at his grave and his belongings burned. Hedin contrasts these funerary customs with the attitudes of the locals who were Buddhists.

During the funeral, the Tibetans observed us from a little distance. Afterwards they expressed their surprise at the amount of trouble we had taken with a dead man. “It would be simpler to throw the body to the wolves,” they said.
Some time later, Hedin experienced firsthand that the Tibetans indeed practiced what they preached.
During our absence, another camel had succumbed, and one of our Tibetans had died. On the way to the camp we passed his abandoned corpse, already disfigured by birds of prey.
That’s what I would call recycling one’s body for the good of nature. And why not?


14 April 2008

A circularly painted turtle

JuvenileTurtle1

I found this hatchling of Chrysemys picta last Friday afternoon on a bridge by a small lake not too far from my house. It was small and its colors blended rather well with the background. I was afraid it was going to get run over by a careless hiker or a cyclist. So I picked it up and carried over to the lake.

JuvenileTurtle2

Once I dropped it in the lake, it quickly ducked under the floating plant debris, perhaps to make itself even less noticeable.

JuvenileTurtle3

The hatchlings of the painted turtle overwinter in terrestrial nests. Evolution has empowered them with the necessary adaptations to survive the freezing winter temperatures. In one study, 7 of 32 hatchlings survived exposure to -10.5°C. They apparently avoid freezing by supercooling.


Appreciations to Butch Norden of the Maryland DNR for confirming the identification of the turtle and bringing to my attention their low-temperature survival feats.


What could have happened next, I will never know

I stepped outside with a tall lady and headed towards her place. Just then, my cousin with some friends appeared. They were on their way to climb the mountain in the back of the city and asked me to join them. I told them the sun was low on the horizon—it was too late to go hiking. They said we’d need only 40 minutes. My gaze moved from my pretty companion to the pinnacle visible behind the rows of houses in front of us. I had to choose between the call of the wilderness and the call of the bedroom.

And then I woke up.

"Saturday you woke me up from a dream
torn out of the pages of a magazine."
Play Tough by The Apples in Stereo


13 April 2008

How snails mate: Oxyloma retusa - Part 2

In Part 1 of this series, I presented some background information on the mating positions of terrestrial pulmonate snails and had a picture of a pair of mating Oxyloma retusa, a land snail in the family Succineidae. To learn more about the behaviors of this species, I've been watching and photographing mating Oxyloma retusa since Friday evening.

Glenn R. Webb published his observations of the mating behavior of Oxyloma retusa in his journal Gastropodia (1:102, 1977). I have so far observed 4 mating pairs and some details in the snails' behavior that Webb missed have already emerged.

The pair in the 1st picture started mating right at the edge of the glass plate they were on, and then the snail on the bottom slid over the edge of the plate and they ended up hanging upside down while continuing to mate.

OxylomaRetusaMating2

This unusual position allowed me to get really close with the camera. In the next picture, the shell of the snail on top (which was actually the snail on the bottom before they flipped over) is not visible and the shell visible at the bottom belonged to the snail that was actually on "top". The arrow points at the spot where their genital openings were facing each other.

OxylomaRetusaMating3
Olympus E-500 with a 35 mm Zuiko lens + 25-mm extension tube; 1/160 s, f13, ISO 160; light was from an Olympus FL-36 flash; both the camera & flash were hand-held.

Notice how close the snails' bodies were to each other at the genital openings. I can't tell by looking at this picture (the actual high resolution image enlarges to a much larger size) if the mating was unilateral or reciprocal. In unilateral mating, only one snail, usually the one on top, inseminates the other, while in reciprocal mating, both snails inseminate each other (remember they are hermaphrodites). I even examined another pair in a similar position under the stereomicroscope and still couldn't tell how many penises were taking part in their mating.

Webb, on the other hand, claimed that he could tell what I couldn't.
The the animals relaxed and the two penises could be seen to conjoin the pair in reciprocal coitus.
There are other details in my observations that differ from those of Webb. I need more data, however, before I can decide that what I am seeing are consistent behavioral traits.


11 April 2008

Hyenas, foxes and wild cats in the Middle East

It's amazing that in the Middle East, after thousands of years of exploitation and abuse by humans, there are still large mammals left in the wild.

Abi-Said & Abi-Said (2007) report that striped hyaenas (Hyaena hyaena syriaca) remain widely distributed in Lebanon. Although their survey doesn't give any indication of what the population levels of the hyaenas may be, it does show that the hyaenas are, unfortunately, still being persecuted; national newspapers reported 23 incidents of hyaenas having been killed during 1999-2001. Curiously, among the 2 nature reserves included in the survey, one had the lowest relative abundance of hyaenas, while the other had no signs of them.

Among the 3 factors the authors think may have contributed to the continuing presence of the striped hyaena in Lebanon, one is especially ironic.

The civil war of 1975-1991 and the Israeli invasion of 1982 resulted in the displacement of many people from their own villages. Furthermore, the land was extensively land-mined by the warring parties. As a result, people were forced to leave their lands, which in turn grew wild, thereby restoring some lost habitats for wildlife.
So, at least in this case, the bloody human conflicts were good for something. Another contributing factor they cite is the presence of widespread garbage dumps throughout the countryside, which apparently provide food for the omnivorous hyaenas. War and human waste coming to the rescue of wildlife? It sort of shows us the position of Homo sapiens in the grand scheme of things, doesn't it?

Another paper in the same issue of the Zoology in the Middle East (Serra et al., 2007) reports the occurrence of Rüppell's fox (Vulpes rueppelli) and the sand cat (Felis margarita) inside the Al-Talila Reserve in Syria. It's good to know that at least some animals are making use of the wildlife reserves.


Mounir R. Abi-Said & Diana Marrouche Abi-Said (2007). Distribution of the Striped Hyaena (Hyaena hyaena syriaca Matius, 1882) (Carnivora: Hyaenidae) in urban and rural areas of Lebanon. Zoology in the Middle East 42: 3-14.

Serra, G., Abdallah, M.S. & Al Qaim, G. (2007). Occurrence of Rüppell's Fox,
Vulpes rueppelli, and sand cat Felis margarita in Syria. Zoology in the Middle East 42: 99-101.

10 April 2008

Any way you spell it, it's Saccharomyces cerevisiae

I work in an office where we mostly review and write documents. Sometimes, matters that may appear frivolous to outsiders become subjects for serious discussion among ourselves. Today was one of those days. Whilst writing a document, I realized there were 3 possible spellings of the common name of the yeast Saccharomyces cerevisiae: baker's yeast, bakers' yeast, bakers yeast.

I sent out an e-mail to some of my coworkers asking for their input. Later we noticed that we had already used "bakers yeast" in some of our old public documents. That usage set a precedent and we decided to stick with it, although I personally would have preferred "baker's yeast".

After I came home, I did a Google search and got the following numbers of hits.

baker's yeast: 350,000
bakers' yeast: 66,600
bakers yeast: 66,500
Saccharomyces cerevisiae: 4,090,000
Saccharomyces cerevisae: 146,000


Return of the bdelloid rotifer Macrotrachela sonorensis

The first animal species that I ever described was a bdelloid rotifer, Macrotrachela sonorensis, that I had found in a Mexican desert during a vacation (Örstan, 1995). As years went by, I started having doubts about the validity of that species and started questioning my judgment and desire to rush to print with what may have been inadequate sampling. In fact, Segers (2007) in his annotated checklist of rotifers included Macrotrachela sonorensis as a “species inquirenda”.

I can now rest assured, however, for Bill Birky at the University of Arizona reports on his lab page, with photographs, the rediscovery of Macrotrachela sonorensis also from a desert area, but this time in Arizona.

The indomitable bdelloid rotifers have been on this blog before (here and here). In today’s edition of Nature, there is a news article about David Mark Welch of the Marine Biological Laboratory in Woods Hole and the research he has been doing with bdelloids. Bdelloids appear to have evolved highly efficient mechanisms to repair their DNA, which is likely to get damaged during frequent episodes of desiccation most species are exposed to in their ephemeral aquatic habitats. The organization of the bdelloid genome is tetraploid, that is, instead of the more usual one pair of chromosomes, there are 2 pairs of similar chromosomes. According to David, bdelloids’ extra chromosomes may explain how they can repair their DNA efficiently and thus survive extreme desiccation in the wild and high doses of radiation in the laboratory that would turn most other creatures into heaps of dust.

The distribution of Macrotrachela sonorensis seems to be restricted to deserts, although it’s hard to be sure with only 2 records so far. This, of course, leads to the question of which came first. Did the bdelloids evolve their tetraploid genome and the associated DNA repair mechanisms before they became adapted to life in ephemeral habitats or did the repair mechanisms originate after they started living under precarious conditions? I suspect repair mechanisms and various other physiological and morphological adaptations that enable them to survive in the absence of water, such as their ability to contract their bodies into little balls, coevolved in perhaps slowly evaporating coastal brackish water ponds.

I’d better stop before speculation gets out of control.


Segers, H. 2007. Annotated checklist of the rotifers (Phylum Rotifera), with notes on nomenclature, taxonomy and distribution. Zootaxa 1564: 1-104. pdf

Örstan, A. 1995. A new species of bdelloid rotifer from Sonora, Mexico. Southwestern Naturalist 40: 255-258. (One of these days I will scan this paper and put it up on the Internet.)


09 April 2008

Nautilus: still evolving after 500 million years

Nautilus1

This is a Nautilus shell that I photographed at the Carnegie Museum of Natural History in Pittsburgh last October when I was there for the OVUM meeting. Nautiluses are cephalopod mollusks with external shells. The cross section of the shell in the next picture shows the unusual internal structure that leads to the common name "chambered nautilus". The animal occupies the very last chamber that opens to the outside. As its body grows, it secretes more shell and moves forward within its shell; a portion of the shell space it used to occupy then gets partially sealed and filled with gases from its own body. These gas-filled chambers inside its shell provide a nautilus with neutral buoyancy.

Nautilus2

Nautiluses have been around for about 500 millions years. The fossil record indicates that there were many more nautilus species in the past than there are now and the extant species don’t seem to have changed much compared to their fossil relatives. Therefore, the common notion is that nautiluses are living fossils, perhaps near the end of their evolutionary journey.

In an article in this week’s New Scientist, Peter Ward of the University of Washington challenges those ideas.
The idea of nautiluses as living fossils now has to be rejected...What we are witnessing is not the final flickering of an ancient group, but a vigorous radiation of new species.
This new assessment derives from recent research that has shown that there are actually more extant species of nautiluses than were formerly realized. In fact, some of the species that were previously lumped in the genus Nautilus are now in the relatively new Allonautilus. According to the article, the present day nautilus lineage may have originated around New Guinea as recently as 2 million years ago and the splitting of the Nautilus and Allonautilus lineages may have taken place even more recently.

Stay tuned for more new species.

Unfortunately, because of overharvesting, nautilus populations are becoming increasingly threatened. There is a short review of their conservation status here.


08 April 2008

Who preys on Truncatella?

Occasionally, while examining a high-resolution picture on my computer monitor, I may see details in the picture that I didn’t notice while taking the picture. An example was discussed in this post. This happened again recently. When I was in Florida near the end of March, I photographed a crawling Truncatella in its habitat within a pile of seaweed stranded behind a beach. Later at home, I was disappointed that the picture of the crawling Truncatella itself wasn’t very revealing, but in the same frame I saw something else that was more interesting and that had escaped my attention in the field: a peeled empty Truncatella shell (near the right hand corner).

PeeledTruncatella1

If I had noticed that shell in the field I would have taken it. But a day later, there was no hope of finding a particular shell that was only a few millimeters long among seaweeds even if I had remembered the exact spot where I had taken the picture. Luckily, however, I have a few similarly peeled Truncatella shells in my collection. Here is one of Truncatella caribaeensis (shell length=~4 mm).

PeeledTruncatella2

Crabs are known to peel the shells of marine gastropods that they prey on. Could it be that tiny juvenile crabs practice their skills on the equally tiny Truncatella before moving on to larger snails? Carabid beetles, which are known predators of land snails, are another possibility. So when I found this beetle (~11 mm long) on the same beach under a pile of seaweed where there were also lots of Truncatella, I got excited. I thought maybe this was the Truncatella predator. I must admit, though, that I don’t know if this was a carabid* or not.

BeachBeetle

I took the beetle and some live Truncatella home, put them in a petri dish with some damp sand and seaweed. For about a day and a half I checked the dish several times in hopes of finding peeled shells. But, alas, there were none. The Truncatella kept crawling around while the beetle hid under the sand. Eventually, I returned them all to the beach.

The mystery peeler of Truncatella remains at large.

*Note added later: Since I posted the picture of the beach beetle on BugGuide.net, it has been identified as a Scarites sp. in the family Carabidae as I had suspected.


07 April 2008

Aldat the yak hunter and how he got enough vitamin C

I am still reading Sven Anders Hedin’s My Life as an Explorer (1925) (previous posts about that book are here and here). During his travels in Asia, Hedin encountered and interacted with many characters who lived in the wilderness more or less isolated from the society. One of them was a man named Aldat in Tibet in circa 1900.

This Aldat was of Afghan descent. He spoke Persian. He had an eagle nose, a short beard, and eyes full of melancholy. He was a yak-hunter by profession, and lived alone in the mountains all year round. His food consisted of the flesh of the wild yak, and his drink was snow-water. His possessions were limited to the clothes on his body, a fur robe, a rifle, and ammunition. In the summer, his brothers would come up, with donkeys, to fetch the skins of the yaks he had killed.
My first reaction to this account was of disbelief. How can one survive only on meat and water? Wouldn’t the person eventually develop scurvy from lack of vitamin C? To satisfy my curiosity, I did some reading and then some calculations.

The 1st piece of information I needed was how much vitamin C yak meat can provide. But I assumed that information would be difficult to find and I didn’t bother to search for it; instead, I substituted beef for yak meat. According to the USDA Nutrient Database, a 100-gram portion of cooked beef tongue provides 1.3 mg vitamin C and 284 kcal energy, while a 100-gram portion of cooked beef liver provides 1.9 mg vitamin C and 191 kcal energy. In comparison, 30% fat broiled ground beef has 0 mg of vitamin C per 100 g of meat.

Next, I needed to know how much daily food energy Aldat would have required. Luckily, a paper by Rodahl (1954) had the answer. According to Rodahl, trappers in Greenland could maintain their body weight on an average of 3,000 kcal per day, energy requirements of adult Eskimos in Greenland were estimated to be 2,800 to 2,900 kcal per day and the U.S. infantrymen stationed in Alaska consumed a mean of 3,200 kcal per day with no weight change. Although Rodahl cites some higher values of energy consumption by people engaged in more strenuous activities, for example, arctic miners and explorers, I will assume that the daily energy intake requirement of Aldat, who lived in a cold climate and was probably physically active most of the day, was 3000 kcal.

I can now calculate that Aldat could have fulfilled his energy requirement by eating everyday about 1 kg of yak tongue or about 1.5 kg of yak liver. Assuming that the vitamin C contents of yak body parts are similar to those of cows, Aldat would have gotten about 13 to 29 mg of vitamin C every day from eating tongues and liver. We have good reason to assume that he may have indeed eaten tongues, because, according to Hedin, tongues, along with kidneys and hearts, were considered to be the best parts of a yak’s flesh.

Finally, I needed to know if, say, about 10 mg vitamin C per day would have been enough to prevent Aldat from getting scurvy. The answer came from a paper by Carr & Frei (1999), who, citing another paper, state that 10 mg of vitamin C per day can prevent scurvy.

Therefore, Aldat could have avoided scurvy on his yak-only diet. That conclusion notwithstanding, Aldat wasn’t a healthy individual. He joined Hedin’s team as a hunter, but 2 months into a difficult expedition over the mountains of Tibet, he got sick. He suffered from headaches, nose-bleeds, delirium, low body temperature and his feet turned black. He died within 3 weeks.

Hedin apparently never figured out what had driven Aldat to the lonely mountains.
Aldat was charmingly mysterious. He was like a disguised prince in a fairy-tale. He answered all questions briefly and correctly, but did not speak unless questioned. He was never seen to smile or laugh, or to talk with the other men. It was as though he were fleeing from a great sorrow, and sought solitude, danger, and the hard, adventurous struggle against the wolves and the storms.


Anitra C. Carr and Balz Frei. 1999. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am. J. Clinical Nutrition, 69: 1086 - 1107.

Kaare Rodahl. 1954. Nutritional Requirements in Cold Climates
J. Nutr. 53: 575-588. pdf


06 April 2008

Egg of Megalobulimus ovatus

Back in March we had the Mid-Atlantic Malacologists meeting at the Delaware Museum of Natural History in Wilmington, Delaware. During the lunch break and for about an hour after the meeting I was able to work in the mollusk collection.

While looking at a drawer full of specimens of the land snail family Megalobulimidae, I noticed a glass vial with a peculiar object in it.

MegalobulimusEgg1

The museum label identified it as an egg of Megalobulimus ovatus. It measured 34.5 mm by 18.1 mm. When I shook it gently, I could hear something rattling inside.

MegalobulimusEgg2

I had never seen such an elongated snail egg before. In fact, I had thought that all eggs were more or less spherical. But an Internet search found photos of similar looking eggs attributed to megalobulimid species (example).

The snail that laid that egg must have been rather large. I am not familiar with the Megalobulimidae, but most species in the family appear to be able to grow quite large. Here is one example.

Strophocheilus

This one was identified as Strophocheilus popelairianus from Ecuador, but I can't vouch for the correctness of that identification.


Sunday morning translation Zen

I have been reading Enlightenment Unfolds, a collection of the writings of the 13th century Japanese Zen master Dogen Zenji. The book was translated by several people and edited by Kazuaki Tanahashi. Unfortunately, there is no way I can read Dogen's original writings and it is inevitable that translations will stray from the author's meaning (see this post for examples).

Here are 2 questionable passages from Enlightenment Unfolds (italics mine).

If inherent knowledge is correct awakening, then all sentient beings will automatically become completely enlightened...
According to my Random House dictionary, the word automatic entered the English lexicon around 1750. I very much doubt that the 13th century Japanese had a word with an equivalent meaning. I wonder if naturally or spontaneously would be better replacements for automatic in that sentence.

Here is the 2nd example. This one is from a long paragraph of prohibitions Dogen's teacher is recommending.
"...don't look at pornography or talk about sex..."
Pornography is even a newer word; it dates to the 1840s.

I realize it would be difficult to translate a 13th century text from any language into present day English, but using words of rather recent origins for what may have been esoteric concepts or long phrases doesn't quite cut it.


04 April 2008

It looks like a semislug to me


Cartoon by Dave Coverly


Goodbye Temi

TemiLast

Our beloved Temi reached the end of the road this morning at the ripe age of 19.5 years. We had adopted her in December 1988 when she was estimated to be 3 months old.

Two weeks ago one of her hind legs broke while she was trying to scratch herself. Subsequent X-rays and blood tests revealed that she had what the doctors thought was advanced sarcoma. She survived on pain killers until this morning when the vet determined that her lungs were filling with fluid and her liver was enlarged; we decided it was time to draw the line. The picture above was taken last weekend when I took her out to the backyard for the last time. (The bandage on her front leg was for the IV catheter.)

TemiXray

Since she lived so long, I figured she had some pretty good genes that would be a shame to lose. So I had the vet snip off the tip of her tongue, which is now resting in 95% alcohol in the refrigerator.

TemiTongue

Maybe we'll have her cloned one day!


03 April 2008

Will it be the same without frogs?

In last week's Nature* there was a news report about the removal of highly threatened frogs from their habitats to captive breeding facilities.

Besides relentless habitat loss, one of the biggest threats to frogs is the often fatal fungus Batrachochytrium dendrobatidis (did I spell that correctly?). Captive breeding programs are expected to protect the highly vulnerable species from the fungus and the other dangers they face in their habitats. According to the article, the International Union for Conservation of Nature has a plan "to transfer 500 members of 500 [frog] species into protective custody within five years." Curiously, though, a brief search on the IUCN site did not find any relevant information.

Anyway, what attracted my attention in the Nature article was the following cautionary note.

A problem of equal complexity is what will happen to an amphibian’s native ecosystem in the amphibian’s absence. It may be that the things it ate will immediately increase in number and the animals that fed on it will become fewer. Such adjustments may lead to other changes in an unpredictable cascade through the ecosystem. Depending on how long the amphibian is gone, its ecological niche might not be there when it returns.
I suppose the removal of a major predator could significantly influence the future population levels of its prey. But if the frogs have already declined in numbers and if their prey (insects, etc.) are abundant anyway, would the frogs' removal would make any difference in the numbers of their prey? Probably not. The same argument also applies to the numbers of frogs' predators. If a species is on the brink of extinction, its influence on its environment has probably already dropped to an insignificant level.

Nevertheless, I think the point raised in the Nature article should be kept in mind. Most ecosystems have complex, intricate organizations that make it almost impossible to predict the outcome of the modifications we impose on them.


*Emma Marris, 26 March 2008, Nature, 452:394-395.


Boxcar graffiti LXI & LXII

BoxcarGraffiti61


BoxcarGraffiti62

Boxcar graffiti LVIII & LVIX & LX


02 April 2008

An Aussie in Florida

AustralianCockroach2

I photographed this big roach one nite last week in my in-laws' backyard in Florida. It was ~3 cm long. A quick search on BugGuide.net identified it as an Australian cockroach (Periplaneta australasiae). The distinguishing characteristic of this species is the yellow border around its thorax.

They were introduced to southern U.S. presumably from Australia, and now appear to have become naturalized at least in Florida. In other words, along with the snail Bradybaena similaris and the myriads of other alien creatures, they are here to stay.

AustralianCockroach1

This particular individual was quite docile. Unlike some other cockroaches I am familiar with (for example, the German cockroach, Blattella germanica), it allowed to get get quite close to it and didn't attempt to run away until after I started poking around with a stick to move the grass blades out of the way for a better picture.


Did the Turkish media fall for the "flying penguins" April Fool’s hoax?

Yesterday, April 1st, the BBC released a video narrated by Terry Jones of Monty Python fame that showed plump penguins soaring thru the Antarctic skies on their stubby wings towards their wintering grounds in the jungles of South America. The video was apparently a promotion for the BBC’s upcoming series Miracles of Evolution.

I know from experience that when it comes to science reporting, the Turkish media is quite naive, shallow and simplistic. A Google search this morning using the phrase uçan penguenler (flying penguins) returned about 1190 hits.

Here are some links to Turkish news sites regurgitating what they had seen on the BBC announcement:

Mynet haber

Haber Turk

SonDakika

It’s not possible to tell if they were aware that this was a joke. A day later, however, at least one site had realized that this was all a hoax:

Haber 3


01 April 2008

Echinoderm book finally put to good use



I bought this book, Echinoderms of Florida and the Caribbean-Sea Stars, Sea Urchins, and Allies, by Hendler, Miller, Pawson & Kier about 9 years ago when it was on sale at the bookstore in the Smithsonian's National Museum of Natural History in D.C. I hadn't had a chance to use it until last week when my son found this sea star at a beach in Florida.

EchinasterSentus1

There are no dichotomous species keys in this book, which is fine with me, because I don't care much for dichotomous keys anyway. Instead, one tries to identify the specimens from descriptions, habitats and the color pictures.

This sea star, apparently a juvenile with a diameter of 55 mm, comes closest to Echinaster sentus. The book, however, notes that the "variability of Echinaster species makes their identification decidely difficult." To make things worse, several other Echinaster species that also occur in Florida are listed, but no clues are given as to how to tell them apart.

EchinasterSentus2