People spoke of him mockingly. They said he behaved strangely, obeyed his wife to the letter. He didn’t hang out with other men after work in the coffee shop. He liked to read, a good-for-nothing sport. He didn’t speak the local accent although he had breathed the air of this town all his life. Presor Dyli didn’t curse or spit on the ground. He was unusually polite and mild, almost like-God forbid-a woman. He was weird, they said. People made fun of his wandering eyes, but that’s too cruel, and I am going to skip it.

I didn’t think of him as weird. He was different yes, but far from weird, if you know what I mean.

When Presor Dyli decided to start the first afterschool club ever in the history of our school, he ensured that he would become the laughingstock of the town for a hundred more years. Nobody knew what the club was about or even what an afterschool club was supposed to be.

Somehow he managed to secure a small room in the municipality building, five old typing machines, and a considerable supply of index cards and pencils.

Presor Dyli asked all his students to enroll in the club. Anything that could be an excuse to get out of the house, away from the never-ending chores, was welcome, so I was happy to oblige.

I remember the first meeting of the club quite clearly. My best friend, Lindita was sitting by my side, and she would giggle every time Presor Dyli looked at us, his wandering eye extremely lapsed in the wrong direction. I became annoyed with her since what Presor Dyli was saying kindled my curiosity. I turned to her sternly and scolded, “Oh, hush for a moment, won’t you?”

She looked at me like I had gone crazy. Little did I care if I had.

His soft voice spoke in unfamiliar words such as noble cause, great service, our language sweeter than honey. I felt like I was transported to a strange new planet.

“My dear children,” Presor Dyli said, “our mother tongue, Albanian, is an old and rich language. Unfortunately, many words used by older generations are about to vanish because they never saw the light of print on the pages of dictionaries. These old words are called archaisms; most of them originate from Ottoman language as a legacy of 500 years of Ottoman rule in Albania.”

“It is our mission to save these words from dying. While listening carefully to adults talking, if you catch a word you have never heard before, write it down on the index cards I will provide for you. At our club meetings we will compare notes, consult the dictionary, and type the words we don’t find in it. Okay? Later, we will mail those words with their meaning and usage to the National Committee for Albanian Language, so that they may be added to the dictionary. I know it sounds complicated but it is easy, you will see. Any questions?”

All twelve of us stood there dumbfounded. My brain felt fuzzy, like a TV which has lost its signal.

Nevertheless, Presor Dyli went on with a new subject–the methodology of our work. After explaining step-by-step the instructions on word hunting, he relaxed our overstretched minds with a story of a smart linguist on an archaism hunt.

“This linguist on an ancient-word hunt went to the farmer’s market. Immediately he spotted his prey-a toothless white-haired lady selling eggs, and he approached her. He asked her how much one egg cost.

She looked at this well-dressed, prospective buyer and smiled. “10 leke,” she said.

Then the linguist did the most unimaginable thing. In a frenzy, he snatched the egg basket and started throwing eggs to the ground, one by one. The old woman, cursing with contempt in her heavy mountainous dialect, fought back with this crazy man. To the surprise of everyone watching, the linguist, delighting in every curse as if receiving blessings from heaven, took out his notebook and excitedly recorded the lingual pearls.

The old woman, making no sense of what had happened, squatted over the broken eggs and cried over the ill fate that had befallen her. Right then, the linguist told her that he would pay for all the eggs he broke, 10 leke each. She did not believe him at first, but when he took out his purse and pulled out the money, she opened up like the sky after a storm. She thanked him effusively and upon hearing that he was willing to pay 15 leke for each, she let flow from her old mouth a string of benedictions. Again, the crazy linguist wrote down whatever she said, as if his own life depended on it.

“Well, children, this is the story of the linguist who dearly loved our language and did everything in hand to preserve it, even wasted eggs and paid for them” Presor Dyli smiled. “Don’t try this yourself though, all right?”

Later he dismissed us with the air of a commander sending his troops on an expedition.

I hugged the pack of index cards he had given me, and on my way home I made a mental list of suspects. I put my grandmother at the top. She was over eighty. She was bound to spill some ancient word from her mouth. Second, came our next-door neighbor, an old lady. “She loves to chat for hours. She gossips a lot too, but if breaking eggs is okay, then I will put up with that.” I decided.

I went to sleep that night, my chest filled with great aspirations for the remarkable service I would render to our mother tongue, which was sweeter than honey.

The next day I lay in ambush for my neighbor on her way to the farmer’s market. She started into her favorite sport-gossip-immediately.

“Did you see how the so and so’s wife was dressed in the so and so’s wedding?” she asked.

I shook my head, but that only invigorated her.

“Her outfit was for hakaret. How could she come in a dress that was so revealing? She should have…”

“Wait, wait a second,” I interrupted. A bulb started blinking in my brain.

“What is hakaret?” I asked, feeling for my pencil and the index card pack in my pocket.

She looked pretty annoyed to deal with words when greater scandals regarding the wife of so and so were involved. She answered anyway, maybe for fear of losing my interest.

“Hakaret means something discreditable, something that people will point their fingers at.

I started scribbling industriously on my index card as she spoke. My neighbor eyed me suspiciously.

“What are you doing?”

“Taking notes.”

“You aren’t going to tell the wife of so and so about what I said, are you?” She looked worried.

“Oh no, no. This is something related to my language club assignment.” I assured her.

Unconvinced, she decided to take no further risks and bade me good-bye, murmuring something about not wanting to miss the fresh eggs in the market.

As I watched her hurry away looking flabbergasted, I wondered if she would tell someone in the market about her neighbor’s so and so daughter doing strange things with a pencil and some what-you-call-them cards.

That evening I listened all ears, pencil in hand to my grandma complain to Mom about one of her grandchildren, my uncle’s only son among three daughters.

“The child is spoiled rotten and if something isn’t done to bring him to his senses, he will bring shame to all of us. It is as clear as that. As they say, you don’t need a kilavuz to the village for what you can see.”

“What is a kilavuz, Grandma?” I asked curiously.

Grandma froze, unprepared for this all-out assault. Soon enough she came to her senses and replied, “Kilavuz is someone who leads the way.”

“A guide?” I said, coming to her assistance.

“Yeah, something of the sort. Now why don’t you go and pick some grapes from the vine, wash them thoroughly, and bring us some to eat.”

I went out, sat on the front steps and wrote down with indescribable delight, kilavuz, my second victory. My heart beat with glory.

At the third club meeting I brought three hard-to-find words. You know the first two already. Why, the third came from a street argument among two drunks shouting at each other at the top of their lungs. I just wrote down the word because, as you can figure out, I couldn’t ask them, drunk as they were, about its meaning. I asked my mom instead. She blushed and threatened to make me bite on red hot pepper if I ever spoke that word again. Just as Professor Dyli asked us to hand him our index cards, I erased the third word. I reasoned that our language might do better with one less bad word.

Week by week, month by month, the about-to-be-lost words accumulated, like little streams in a pond. When we finally correctly typed thirty of them, Presor Dyli put the list in an envelope and mailed it with an accompanying letter, explaining our humble service to the National Committee for Albanian Language.

We continued on our word pursuit the rest of the school year, although we didn’t hear back from the NCFAL. Presor Dyli’s matchless enthusiasm fueled our little engines.

During that year, our country was undergoing great changes, although we, young club-goers, took little notice. On the radio, television, the coffee shop, the street, everyone talked about the big transition from over forty years of communism, to democracy. The land and the factories were being privatized and words such as private property and business were articulated boldly for the first time in many years. We brought them over to club–that’s how I remember. Presor Dyli told us that they were new words, therefore of no use to our mission.

My parents talked over dinner each night of how some of our neighbors or their friends had come up with amazing ideas to start a trade, and how courageous it was to take such a risk in the collapsing economy. Some of them had turned their patios into little shops, selling anything they could lay a hand on and stock in such a little space. My parents wished we were living in the walk-in level apartment, so we could try our luck in business. Why, it was such a convenient thing to work so close to your living quarters. I understood nothing of their talk. Nonetheless I listened carefully, my pencil and cards nearby.

At one of our meetings, which I learned later would sadly be the last, Presor Dyli told us apologetically that he had to quit the language club. He had to dedicate his time to something really important.

“I am sorry, children. I tried to find a substitute to keep the club going but to no avail. You kids did a great job. I am proud of you. I am sorry to quit but I have to,” he said in a sad tone. He did not look at us.

We left in silence, wondering what could be so important and so sorrowful at the same time.

Had he come down with a bad disease and he needed to go for treatments? Was he moving to another city? Had he received a disheartening letter from NCFAL? What could it be?

Weeks went by. Presor Dyli still taught us language arts during regular school hours but as soon as the last bell rang, he would hurry in the direction of his apartment. I had been taught to never pry. That’s why, tempted as I was, I never followed him.

One day, I took another way home after school because I had to take a make-up assignment to a sick classmate. I was entertaining myself with my shadow sliding ahead of me on the pavement, when his voice startled me.

“One kilogram tomatoes, two dozen eggs, one box of matches. Anything else I can get for you, sir?”

Yes, it was him. In his apartment’s patio which had been converted into a shop. I couldn’t believe it! He still had on his morning attire-white shirt and black pants. A black apron hung loosely about him and his shirt sleeves were rolled up. He had tomato stains on his shirt.

“No thanks,” replied the customer as he handed him the money.

As Presor Dyli rummaged in the big front pocket of his apron for change, a passerby who was the age of my father, stopped at the door of the shop and shouted.

“Hey Abdyl, how is it going? You’ve got a pretty good-sized shop here. Hang in there, buddy and before you know it, you will own a big market, just like Naim. He started small like you but look at him now. Has money to cover himself standing. I am happy for you, man.”

He made his point and patted Presor Dyli on the shoulder.

“Finally the cat caught a mouse, eh, Abdyl? “

I was about to cry. This little business was his really important something. What’s worse, he didn’t even mind being compared to the ill-famed Naim, a mafioso who was known to sell anything illegal.

Presor Dyli looked up. He saw me standing on the pavement across the street, like a statue of salt. He tried a genuine smile and waved at me, a bit hesitantly.

I was waking up from the dream.

He had lost his charm. I had lost my aspirations. He wasn’t weird anymore by the town’s standards. He was Abdyl now.

I didn’t wave back. I moved on and let my tears flow.

Each creation is a work of art. All animals and plants, as well as every human being, are unique and priceless. And those who appreciate their value are like antique dealers as in the passage above. I recently had the chance to listen to such an “antique dealer,” Joanna Aizenberg of Bell Laboratories/Lucent Technologies, and witnessing the appreciation of the valuables she presented to us helped me better understand Said Nursi. Both the valuable object she was talking about and her appreciation of it were equally inspiring for me, and this is the reason why I have decided to share this story with you. Without any further ado, here is the story of a sponge species called the Venus’ Flower Basket and its “eternally” incarcerated residents: a pair of shrimp. Now, you must find what is hiding behind all this; after all, it is the eyes that look but the heart that perceives.

Venus’ Flower Baskets (Figure 1a) are vase-like sponges that grow upright on the sea floor of the Pacific Ocean, mostly around Japan. They have a very sophisticated mesh structure which caused medieval Europeans to assume they were glasswork made in China. In Japan they are called Kairou-Douketsu (together for eternity) and given as wedding gifts, since they generally house a pair of mated shrimp which are trapped in their cavity. As you have probably already understood, our story is about the engineering secrets of these sponges and their relationship with their guests.

The design

The skeleton of the Venus’ Flower Basket is made of silica, which is a very brittle material (remember the glass windows that you broke with your football when you were a kid; they were made with silica). How can these amazing creatures withstand the pressure and the currents present at the sea floor or the disturbance caused by two shrimp? The secret lies in the hierarchical construction of their cylindrical cage-like structure. As can be seen in Figure 1b, their skeleton is made up of beams that run perpendicular and parallel to the axis of the sponge, which forms a rectangular grid. This grid is further supported by beams that run diagonally in both directions. Finally, this whole structure is reinforced by ridges that spiral around. But these are just the macroscopic hierarchical levels of the construction. Now let’s start from the very first level of this hierarchy and try to understand how each level adds to the stability of the sponge.

The basic building block of the Venus’ Flower Baskets is a fiber composed of silica nano-spheres (Figures 1i and 2a) that grows around an organic filament (the black dots at the center of the circles in Figure 1f). Though this fiber is not very stress tolerant, due to the size of the spheres from which it is made, in the next level of hierarchy it is toughened by alternating organic and silica sheets that form a concentric lamellar (fine, alternating layers of different materials) fiber structure. The thickness of each layer in the fiber decreases from 1.5 (: 1/1000 mm) at the center to 0.2 towards the periphery (Figures 1f, 1g and 2b). Hence any crack that is initiated at the periphery is halted at the organic interlayers and while the thinner outer layers lessen the depth of crack propagation, the thicker inner layers enhance mechanical rigidity (in addition to their mechanical stability, these silica fibers are endowed with optical properties which are superior to man-made fibers, which will be discussed later on in the article).

Figure 1. Structural analysis of the mineralized skeletal system of Euplectella sp. (a) Photograph of the entire skeleton, showing cylindrical glass cage. Scale bar, 1 cm. (b) Fragment of the cage structure showing the square-grid lattice of vertical and horizontal struts with diagonal elements arranged in a chessboard manner. Orthogonal ridges on the cylinder surface are indicated by arrows. Scale bar, 5 mm. (c) Scanning electron micrograph (SEM) showing that each strut (enclosed by a bracket) is composed of bundled multiple spicules (the arrow indicates the long axis of the skeletal lattice). Scale bar, 100 mm. (d) SEM of a fractured and partially HF-etched (25) single beam revealing its ceramic fiber-composite structure. Scale bar, 20 mm. (e) SEM of the HF-etched (25) junction area showing that the lattice is cemented with laminated silica layers. Scale bar, 25 mm. (f) Contrast-enhanced SEM image of a cross section through one of the spicular struts, revealing that they are composed of a wide range of different-sized spicules surrounded by a laminated silica matrix. Scale bar, 10 mm. (g) SEM of a cross section through a typical spicule in a strut, showing its characteristic laminated architecture. Scale bar, 5 mm. (h) SEM of a fractured spicule, revealing an organic interlayer. Scale bar, 1 mm. (i) Bleaching of biosilica surface revealing its consolidated nanoparticulate nature (25). Scale bar, 500 nm. Figure and captions from ref. 2.

Fibers of different diameters reinforced this way are then bundled loosely in a silica matrix (Figure 1d and 1f). The different diameter of the fibers in the bundle and the weak lateral bonding between them are essential for increasing the strength of the bundle against crack propagation. At the next level of hierarchy, these bundles are used as building blocks of the cylindrical cage of the sponge, being arranged horizontally and vertically into a square grid. This grid in turn is reinforced by diagonal bundles that run in both directions along every second square lattice. The minimum number of pin-jointed struts (i.e. ones that are free to rotate at the joints) per node needed in order to form a rigid two-dimensional grid has been shown to be six; this is the number present in the skeleton of the Venus’ Flower Basket. In fact, if the diagonal bundles were to run along every square lattice, the number of struts per node would be 8, which would be redundant for the stability in the skeleton.

At the early stages of the growth of the Venus’ Flower Basket the struts are not connected at the nodes. However as the sponge gets older the struts are joined by a silica cement which itself also has a lamellar structure (Figure 1e). Hence, while the younger sponges are flexible, the older ones are stiff; this also has important implications for the symbiotic relation that the sponge has with its guests, the shrimp. (This issue will be discussed in detail when the lifecycle of the shrimp is examined.) While the resulting grid is stable in two dimensions, in three dimensions it may still suffer from exterior effects, such as ovalization. This problem however is solved at the next level of hierarchy by the helical ridges that surround the grid (Figure 1b). The absence of the ridges at the base of the skeleton of the sponge where the cage diameter is small, and their increased density further up the cage where the diameter is much greater is proposed as evidence supporting this argument. Finally, this whole cage structure must be anchored to the sea floor in a way that will withstand the bending stresses caused by the currents. This is managed through the use of the fibers that have been discussed earlier; they are used as connectors between the base of the sponge that is anchored to the sea floor and the vertical struts of the skeleton, resulting in a flexible connection that enables the cage to swing freely in the currents (Figure 1a).

As a conclusion, it can be said that “The resultant structure might be regarded as a textbook sample in mechanical engineering, because the seven hierarchical levels in the sponge skeleton represent major fundamental construction strategies, such as laminated structures, fiber-reinforced composites, bundled beams, and diagonally reinforced square-grid cells to name a few.”

Now let’s concentrate more on the fibers (or spicules) that anchor the cage to the sea floor. These anchorage spicules (a term used for describing the skeletal structures of sponges which comes from the Latin word speculum, meaning the head of a spear or arrow)* are 5-15 cm in length and 40-70 um in diameter. In the above discussion we have briefly discussed the cross-sectional structure of these fibers that gives them their flexible, but resistant nature. Here we will focus on the optical properties of these spicules. But before doing so, let’s briefly explain how optical fibers work.

Optical fibers are silica fibers of a 5 to 80 um diameter that are coated with a cladding layer; light waves can travel in these for long distances by constantly bouncing off the cladding. The reason for this is the refractive index difference between the silica core and the cladding layer. Refractive index (n) is a measure of the ability of a medium to change the phase velocity of light and cause the light waves to bend while leaving one medium and entering another (refraction); in the case of fiber optics, leaving the core and entering the cladding. However, if the refractive index of the second medium is lower than that of the initial one, the incident light waves that have an incidence angle higher than a critical value or critical angle can be reflected back to the first medium and this is what happens in fiber optics (See red ray in figure 2). If the core diameter is small (5-10 um), light rays can propagate only through a single path in the fiber (which runs parallel to the fiber axis), hence these type of fibers are called single-mode fibers (See Figure 2a). If the core diameter is larger however, (60-80 um) several paths are accessible, and more paths will have incidence angles that are greater than the critical angle, hence they are called multi-mode (See Figure 2b).

Now with this information in mind, let’s have a look at the characteristics of the anchoring spicules of the Venus’ Flower Basket. First of all, as mentioned in the previous discussion, the lamellar structure of these spicules prevents crack propagation, which is the main failure mode of commercial silica fibers. This lamellar structure, however, also determines the dependence of the optical behavior of the spicules on the environment in which they are embedded. For instance if the spicules are embedded in an epoxide medium with a refractive index of 1.57, the spicule as a whole would not be able to act as an optical fiber, due to the smaller refractive index of the cladding. However, since the core region of the spicules has a slightly higher refractive index than that of the cladding, the core acts as a single mode fiber in such an environment (see Figure 2a). In sea water-the spicules’ native environment-which has a refractive index of 1.33, the whole spicule acts as a multimode fiber, since the refractive index difference between the core and the cladding is much smaller than that between the cladding and the surrounding sea water.

Another advantage of these spicules over man-made fibers is their formation/production parameters, which are ambient temperature and pressure; these enable the introduction of impurities into the silica. Though at first it may not sound as if impurities are a positive characteristic, these impurities are very important for increasing the refractive index of silica and act as dopants (impurity elements added to a semiconductor lattices in low concentrations in order to alter the optical/electrical properties of the semiconductor). The core section of the spicules, for instance, shows increased sodium concentration, which is the cause of the higher refractive index of this section. Such dopant introduction in the silica during the fabrication process, however, is not possible in the case of man-made fibers, due to the very high processing temperatures.

In addition to this, the spicules have crown-like caps at their base and thorn-like structures throughout their middle section. While the crown-like termini most probably are used to anchor the sponge to the ocean floor, it has also been shown that the waveguiding efficiency of the spicules increases when the illumination comes through the end that has the crown-like structure. Hence, it has been proposed that this structure may be acting as a light harvesting lens. The thorn-like structures, on the other hand, share the lamellar construction of the spicule body, and the light guided through the body branches out to these spines and emerges at the tip. Since sea water comes into contact with the tip at an almost perpendicular angle to the guided light, the coupling is pretty efficient. Hence the combination of crown-like ends and thorn-like structures forms optical networks that collect and distribute light. However, at the depths inhabited by the Venus’ Flower Baskets there is no accessible light source. If one accepts the fact that there is no waste in nature-whether one believes in “creation” or “evolution”-the existence of such an advanced network-like structure as a part of a sponge-the most primitive animal-is at least thought-provoking. In the case of sponges that dwell in shallower waters with similar spicules, it has been postulated that such spicules gather and provide sunlight for the sponge’s endosymbiotic algae. However, at the depths at which the Venus’ Flower Baskets live, direct sunlight is not available. However it has been suggested that if light sources, such as bioluminescent microorganisms (bioluminescence is the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy) or chemiluminescence (emission of light as the result of a chemical reaction) exist, their light may be efficiently distributed by the sponge and act as an attractant for juvenile shrimp that are searching for a host. But for now these suggestions are just speculation and merit further investigation.

Before concluding this section, we should also note that, as a natural outcome of their construction/composition, these spicules do not have as great a transparency as their industrial counterparts and light cannot be transferred over long distances with them. However, it seems this is not a problem for the Venus’ Flower Basket as, apparently, they just need fibers of 5-15 cm to survive and it is the scientists who need to figure out a way to incorporate the traits of the Venus’ Flower Basket into industrial fibers.

The love

As mentioned in the introduction, the Venus Flower Basket hosts a pair of mated shrimp. These belong to the family of Spongicolidae, the Spongicala japonica. These shrimp, which can be as “big” as 9 mm in length, spend most of their lives in their host sponge. Though studies about them are limited, it is believed that before permanently being entrapped in their host, the shrimp have two free- living periods. The first one is just after hatching when they are small enough to exit through the mesh of the sponge. During this period they exit and re-enter their cages and live in a group with their parents and other juveniles. Studies suggest that the females generally stay with their parents until sexual maturity, whereas the males tend to leave their original host and live a solitary life until they reach a length of about 4 mm.

The second free-living period comes at the time of sexual maturity, when it is believed that the male and female mate outside and then invade a host, or the female searches for a host that is already occupied by a solitary male. During this stage, the shrimp have a body length of 3.5 to 6.5 mm which is bigger than the mesh size of the host sponges. Though this seems puzzling, it is thought that the mated shrimp enter the sponge in its flexible stage-when it may be easier to penetrate through the mesh-and get trapped there “forever” as the sponge grows older and stiffer. In fact this theory is supported by the finding that several flexible sponge specimens host solitary and young mated shrimp, whereas in the stiff specimens only very few solitary and young mated shrimp have been observed.

References

1. “Biological glass fibers: Correlation between optical and structural properties.” J. Aizenberg, V. C. Sundar, A. D. Yablon, J. C. Weaver, and G. Chen, Proc. Nat. Ac. Sci. 101 3358 (2004).

2. “Skeleton of Euplectella sp.: Structural hierarchy from the nanoscale to the macroscale.” J. Aizenberg, J. C. Weaver, M. S. Thanawala, V. C. Sundar, D. E. Morse, P. Fratzl, Science, 309 275 (2005).

3. “Fibre-optical features of a glass sponge – Some superior technological secrets have come to light from a deep-sea organism.” V. C. Sundar, A. D. Yablon, J. L. Grazul, M. Ilan, J. Aizenberg, Nature 424 899 (2003).

4. “Skeletal growth of the deep-sea hexactinellid sponge Euplectella oweni, and host election by the symbiotic shrimp Spongicola japonica” (Crustacea: Decapoda: Spongicolidae). T. Saito, I. Uchida and M. Takeda J. Zool., Lond. 258 521 (2002)

5. “Pair formation in Spongicola japonica (Crustacea: Stenopodidea: Spongicolidae), a shrimp associated with deep-sea hexactinellid sponges.” T. Saito, I. Uchida and M. Takeda J. Mar. Biol. Ass. U.K. 81 789 (2001).

Note

*. Also defined as, one of the minute calcareous or siliceous bodies that support the tissue of various invertebrates (Merriam-Webster’s English dictionary)