Unusual facts about the sea sponge. Sea sponge (euplectella) is a storehouse of new technologies. What have we learned

Including about 10,000 known species living on Earth today. Members of this type of animal are calcareous sponges, ordinary sponges, six-rayed sponges. Adult sponges are sedentary animals that live by attaching themselves to rocky surfaces, shells, or other underwater objects, while the larvae are free-swimming. Most sponges live in the marine environment, but a few species can be found in freshwater.

Description

Sponges are primitive multicellular animals that do not have a digestive, circulatory or nervous system. They have no organs and the cells do not organize a well-defined structure.

There are three main classes of sponges. Glass sponges have a skeleton that is made up of brittle, glassy needles formed from silica. Ordinary sponges are often brightly colored and grow larger than other sponges. Ordinary sponges account for more than 90 percent of all modern types of sponges. Lime sponges are the only class of sponges that have spicules composed of calcium carbonate. Lime sponges are usually smaller than other members of the type.

The body of a sponge is like a bag, perforated with many small holes or pores. The walls of the body are made up of three layers:

• the outer layer of flat cells of the epidermis;
• middle layer, which consists of gelatinous substance and amoeboid cells migrating within the layer;
• the inner layer is formed from flagella and collar (choanocytes) cells.

Nutrition

Sponges feed by filtering water. They suck in water through pores located along the entire body wall in the central cavity. The central cavity is lined with collar cells, which have a ring of tentacles surrounding the flagellum. The movement of the flagellum creates a current that retains water flowing through the central cavity into a hole in the top of the sponge called the osculum. As water passes through the collar cells, food is captured by the rings of tentacles. Further, food is digested in food or amoeboid cells in the middle layer of the wall.

The water flow also provides a constant supply of oxygen and removes nitrogenous waste. Water exits the sponge through a large hole in the top of the body called the osculum.

Classification

Sponges are divided into the following major taxonomic groups:

• lime sponges (Calcarea);
• Ordinary sponges (Demospongiae);
• Six-beam sponges, or glass sponges (Hexactinellida, Hyalospongia).

These are the most primitive of multicellular animals: they do not have organs, not even tissues, only in some places their initial stages of development are outlined. Sponges have no nervous system and are completely immobile. Only the pores and the mouth can slightly and slowly narrow and expand. But inside the body of a sponge, many cells are able to crawl from one place to another.

Sponges are mainly marine animals; only a few of their species are found in fresh waters. And among them, many well-known, at least by name, bodyaga. Adult sponges sit, as already mentioned, motionless on the bottom or on some objects lying on it.

Sponge sizes range from a few millimeters to two or more meters in height. Most have a short life: from a few weeks to a year or two years (they will live to puberty, grow eggs or larvae in themselves and die). Few have solid longevity. So, a horse sponge, for example, lives up to 50 years or more.

Science knows about 3 thousand species of sponges. Tropical and subtropical waters of the World Ocean are especially rich in them.

The type of sponges taxonomists divide into three classes: calcareous, glass and ordinary sponges.

So, the sponge has no brain, no nerves, no eyes, no ears, no lungs, no stomach, no blood...

But what does she have?

There is a gelatinous body-glass and needles in it instead of a skeleton. Her body is full of holes: these are sponge mouths - pores, there are as many of them as there are stars in the sky - you can’t count them.

As we already know, the sponge can neither move nor even move. But it is a living being. Let's pour dry ink into the water of the aquarium in which she sits. The mascara grains will immediately float to the sponge and disappear in its pores. And then black streams of ink, like smoke from a pipe, will rise up from the neck of the glass - the mouth of the sponge. This means that the sponge sucks water into its pores all the time, pumping it through itself. Small organisms swim into the sponge with water. She catches and eats them.

Sponge

The sponge is very durable. Cut it into five pieces and each piece will grow into a new sponge. Cut the sponge into pieces, sift through a sieve - the sponge will disintegrate into cells. And every cell will live! She crawls, catches prey. Cell to cell is selected, grows together with it. Other cells crawl up and fold together - a new sponge is created from dust particles.

Mix two sponges rubbed through a sieve in a tank of sea water. The cells of each of them will come together (their own will crawl to their own!) and grow together into two former sponges.

This is a sponge in general terms. If we delve deeper into its structure, we will find that the walls of a living “glass” or “bag” are made up of two layers of cells - the outer (ectoderm) and the inner (endoderm). Between them lies another intermediate layer of gelatinous mass - mesoglea. All layers form, so to speak, the walls of the "glass", inside them there is a paragastric, or atrial, cavity. All of it is lined with collar cells, or choanocytes. They look like cylinders with "collars" on the side facing the inside of the paragastric cavity. Movable flagella protrude from the collars. With their vibrations, they drive water into the sponge, flowing, as mentioned above, through the pores and flowing out through the mouth.

Various sponges

This is the simplest sponge device: the axon type. Only in young and a few adult sponges does it remain, so to speak, pure. Most sponges complicate the described structure with age, mainly due to the thickening of the mesoglea and the formation of flagellar canals and flagellar chambers. But in general, they retain in their main features the “standard design” of a porous, hollow glass with an open mouth at the top.

“Some sponges are brightly colored: most often yellow, green, brown, orange, red, less often purple. In the absence of pigment, they have a whitish or gray color. V. M. Koltun).

The skeleton of a sponge - needles that fill the mesoglea in abundance - are microscopic, in shape - uniaxial (simple "rods"), triaxial ("in the form of three mutually intersecting axes at right angles"), four-axial and multiaxial. Sometimes the needles are connected at the ends, forming an openwork lattice. Sometimes a special cement holds them together into a more durable "stony skeleton". The substance from which the needles are formed: in some sponges - silicon, in others - calcite.

But there are also horny sponges, devoid of any needles. The support for their body is made up of elastic organic fibers of the so-called spongin.

“The chemical composition of spongin is close to silk, moreover, with some, sometimes quite significant (up to 14 percent) iodine content” ( V. A. Dogel).

The walnut sponge, which people washed for many centuries (even the Aegean Greeks used it for this purpose), is nothing more than the skeleton of a horny sponge. It is mined in the warm Mediterranean Sea, mainly off the coast of Greece and Egypt. People dive for it to the bottom, then dry it in the sun. The sponge rots, leaving only the skeleton. It is porous and soft, like silk, absorbs water well and lathers soap.

Scheme showing the structure of the sponges: A1 - Ascon type; A2 - Sicon type; A3 - type leukone; B1, B2, B3 - various forms of sponge skeleton needles; C1, C2 - collar cells, or choanocytes

Sponges are now hunted not only in the Mediterranean, but also off the coast of Florida, in the West Indies and in various parts of the Pacific Ocean. There were even some kind of "farms" for breeding sponges, which are cut into pieces and "seated along the bottom of the sea." It will take some time, and quite full-fledged sponges will grow out of these pieces.

“Three main varieties of sponges are mined in the Mediterranean Sea: walnut (honeycomb), Turkish izimokka. Of these, Turkish is the most delicate in structure. There is also the “elephant ear”, so called because of its shape, etc.

Florida sponges are rougher than Mediterranean sponges. These are the so-called “sheep wool”, “yellow”, “velvet”, “grass” and “glove” ”( F. S. Ressel, C. M. Yong).

In the spongy fibers of some horny sponges, there are still flint needles (although there are few of them). For example, in a freshwater bodyagi, which looks like "gray or green growths on underwater objects." For a long time, traditional medicine has appreciated bodyagi: it uses it like mustard plasters - they rub the patient's body with dried bodyaga, while its needles "irritate the skin, cause blood flow to it."

And there are sponges

Asexual reproduction of sponges is a simple division in half (along the longitudinal axis) or budding. When budding, a bulge swells on the mother's body. It grows, the paragastric cavity with the “tissues” surrounding it is drawn into it. Soon, the bud has its mouth, and it falls off from the adult sponge to start an independent life.

In bodyaga, in addition to simple budding and sexual reproduction, which occur in the summer, there are also wintering, or internal, kidneys - gemmules. They are surrounded by a complex shell with layers of air (a heat insulator!). Formed by autumn in the mesoglea. In winter, the bodyaga itself dies, disintegrates, but the gemmules remain at the bottom until spring. Spring will come - gemmules sprout, and a new young bodyaga is obtained.

freshwater sponge bodyaga

It used to be thought that all sponges were hermaphrodites. Later, heterosexuals were also found. But you can’t decide what gender the sponge is in front of you in appearance.

Sexual reproduction begins with the development of sperm and eggs in the mesoglea. Spermatozoa exit into the paragastric cavity, then out of it through the mouth. They swim into another sponge, are transferred by a complex transmission path from one cell to another into the mesoglea and fertilize the eggs there. Those soon begin to split up and develop into a larva. She leaves the sponge that has grown her and swims in the water for some time, setting herself in motion with the blows of the flagella.

Growing up, the larva experiences a number of interesting transformations, which we will not go into. Finally, she, ready to become a sponge, sinks to the bottom, grows to it (by the front end), and now the metamorphosis has already happened - the larva has turned into a young sponge.

Lips are truly versatile. They are involved in eating, talking, smiling and, of course, kissing. But many of us still did not know something interesting about this beautiful and expressive organ. Like what:

1. The thickness of the skin of the lips is four times less than the rest of the skin on the body - all 3-5 layers of the epidermis. As we age, the top layer of the skin becomes even thinner.
2. The lips are very sensitive, many times more so than the pads of the fingers. That is why lips that touched the forehead will more reliably report the temperature than, for example, an attached palm.
3. There are many reflex points on the lips. That is why a passionate kiss can increase the heart rate to 100 beats per minute.
4. Residents of African tribes deliberately stretch their lips by inserting metal plates into them. This symbolizes humility and humility before her husband.
5. Women who use decorative cosmetics for lip makeup use from 2 to 5 kg of gloss or lipstick in their entire life.
6. About 10 percent of women who decide on cosmetic plastic surgery want to change their lip shape so that they look like those of the famous Lara Croft.
7. Kissing on the lips not only gives pleasure and improves mood, but also improves blood circulation, activates the lungs, and also burns calories. Three minutes of kissing is equal to a 10-minute run or a two-hour walk.
8. A kiss on the lips stimulates the production of endorphins and oxytocin in the blood - hormones of joy and pleasure.
9. When we smile, we use 15 labial muscles.
10. The glands that are located on the border of the lips and the inner cavity of the mouth, during a kiss, begin an active release into the body of substances that cause sexual desire.
11. With age, a person's lips become slightly wider, and the upper lip stretches in height.
12. The plump lips of the Hollywood film star Marilyn Monroe are just a visual illusion. In fact, the actress spent a lot of time every day "drawing" their attractive shape on her face.
13. Lips are the first part of the female body that most men pay attention to. After that, legs, chest and other charms follow.
14. In domestic clinics of plastic surgery, 10-15 Botox injections are made daily in the lips.
15. Thin lips can mostly be inherited from the paternal line, while plump lips can be inherited from the maternal side.
16. Herpes - an unpleasant sore that appears on the lips - contrary to popular belief - is not a cold, but a real viral infection, the same as influenza and SARS.
17. In addition to humans, kissing on the lips among animals also exists in horses, chimpanzees and porcupines.

Sponges build glass structures that are marvels of engineering

When you last spoke on the phone or connected to the Internet, you most likely used optical fibers. We hear a lot about them, but what exactly are they? These are very thin fibers of glass (only twice as thick as a human hair). They consist of a stem and a shell made from a different type of glass. Light travels within the fiber and transmits signals which can reproduce information (sound, image, etc.). The light rays do not leave the fiber as the cladding completely reflects them back into the core.

The invention of optical fibers revolutionized telecommunications in its time. But here's what's interesting:sea ​​sponge Euplectella grows glass spicules, which are excellent optical fibers.

seabed decoration

Sponges are primitive invertebrates. They are firmly attached to the seabed, spending their entire lives motionless. Sponges do not have tissues, organs, respiratory or circulatory systems. They maintain their existence by pumping water through their porous bodies and extracting small nutrients and solutes from it. All sponges are characterized by numerous pores on the outer surface. Water, drawn in through these pores, flows through tubular channels and exits through one or more large holes. There are about 6,000 species of these creatures.

Many sponges form complex and beautiful shapes - colorful tubes, vases, baskets, cylinders, and the like. To maintain such structures, they have an internal skeleton built from needles (spicules). It is interesting to note that these simple creatures are able to build their spicules from minerals or protein fibers.

Fig 1. Glass sponges at a depth of 500 m.

There is a class of so-called glass sponges that build their skeleton out of silicon dioxide (see Figure 1). They grow spicules, which magically join together to form a "glass house".

The best-known species of this class is the species Euplectella, also known as the Venus Flower Basket. Her skeleton is a lattice of silicon dioxide that forms an intricate cylindrical room (see Figure 2). A couple of shrimp usually live in it. At the base of the sponge is a bundle of fibers. Researchers at Bell Labs have demonstrated that the delicate spicules of this sponge are excellent optical fibers.

Fig 2. Intricate cylindrical skeleton of a sponge Venus Flower Basket. A network of large spicules join together to form a lattice structure.

fantastic fibers

Their length is 5-15 cm, and the diameter is 40-70 microns (the thickness of a human hair). The scientists were struck by the similarity of the optical fibers of the sponges to the fibers that people have been developing for many years.

Sponge spicules have a rather complex structure - a pure quartz glass rod is surrounded by concentric layers of organics and a layered shell. The shell plays the role of a coating, as in artificial fibers, making spicules excellent conductors of light.

Sponge fibers have a number of advantages over artificial ones. First, they are produced at low temperatures in ocean waters. Commercial fibers are produced using expensive equipment at high oven temperatures.

Sponge researcher Joanna Eisenberg noted: “If we could only learn from nature, we might discover an alternative way to produce optical fibers in the future.”. Secondly, the fibers of the sponge are very durable - they do not crack or break like artificial ones, in which a small crack begins to easily spread through a fragile material.

Replacing cables or repairing them is an expensive procedure. The boundaries between thin layers of sponge spicules stop crack propagation. At the same time, sponge fibers are very flexible - you can tie them into a knot without losing their optical properties.

Sponges may seem simple and bland, but some of the deep-ocean sponges build complex glass structures that are marvels of engineering.

Thirdly, they are excellent conductors of light, as they contain a small amount of sodium ions, which improve optical properties. The sponge is able to add these ions in a controlled way using organic molecules at normal temperatures. Man-made fibers are produced at high temperatures to partially melt glass. In this case, the addition of controlled amounts of sodium ions presents a problem for manufacturers.

The secret is not easy

What is the secret of sponge fibers? And how does she make them? Researchers at Bell Labs have found that each sponge fiber is composed of separate layers with different optical properties. Concentric silicon cylinders with organic content surround the inner core, which is built from pure quartz glass (See Fig. 3). The sponge uses multiple layers of glass that are held together by an organic adhesive, making the structure extremely resistant to breakage and cracks. The sponge produces strong microscopic fibers by bonding thin layers of glass together. She then gathers the layered fibers together for even greater strength. It looks like a bunch of branches. These ligaments are then placed in the form of a lattice. However, how the sponge does this is still a mystery.

Fig 3. Structure of the spicule of the sponge Euplectella. SEM photograph of a spicule in cross section showing the organic filament (OF), the central cylinder (CC), and the layered coating (SS).

Sea sponge will teach architects

However, the wonders of design do not end there. It turned out that the sea sponge has unique structural properties that give mechanical strength and stability to its fragile material.

The Euplectella sponge uses a set of tricks to transform its fragile skeleton into sturdy structures. The spicules that make up the skeleton of the sponge are arranged in a lattice pattern according to an open criss-cross pattern reinforced with a layer of structureless gelatinous substance (mesogley) that run diagonally in both directions within alternating squares (see Figure 4).

This construction technique is often used in high-rise buildings and houses to resist earthquake stress or shear stress, which can easily collapse an unreinforced square structure.

Recent studies have found seven different levels of structural hierarchy in the sponge. Each structural level corresponds to the fundamental principles of construction and engineering, which are widely used in engineering design, but at the same time, on a scale 1000 times smaller than the building.

"The skeleton of this creature is simply a mechanical engineering textbook, offering valuable insights that will lead to new concepts in materials science and engineering design" Joanna Eisenberg said.

Fig 4. The structural details of the sea sponge Euplectella follow the engineering principles used in the construction of buildings such as the Swiss Re Tower in London, the Hotel De Las Artes in Barcelona and the Eiffel Tower in Paris.

Future technologies

The scientists hope to replicate the sponge's biological processes to produce advanced fibers and systems, while acknowledging that “modern technologies cannot yet compete with the sophisticated optical systems of organisms”.

A sea sponge could teach engineers and architects how to build remarkably strong structures out of fragile material.

“These sponges fit perfectly, with the exact amount of material needed to optimize the design. I can't imagine how a structure of this complexity could be produced by chance." Isenberg says.

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Sponges- animals, but they are more like some plants than animals. They grow on underwater objects such as rocks or plant stems. These creatures cannot move, although some species can shrink when touched. They do not have eyes, ears, brain and nerves, heart and blood. But they catch their food by filtering the water that enters them through thousands of tiny openings and exits from one large one called a mouth. Adult sponges are attached to the substrate, but their larvae are able to actively swim. The larvae find a suitable place, descend and grow into an adult colony of cells, which we call a sponge.

The small ones grow around the mouth of the sponge, the main outlet for water. Branched channels are visible inside the sponge.
Various types of cupped sponges grow in fresh and salt water.
Sponge sea loaf may be of different colors, including green. The hymenial sponge is usually blood red. Some Solenia sponges are also red in color. Columnar lips may be purple or blue. Sponge Callispongia is quite wide, with one mouth. Brain sponges are pink.

A typical formed sponge is not a single individual, more often it is a colony. Sponge cells form a flask-shaped body around the central cavity. The walls of the body are pierced by many tiny holes and channels leading from the outer holes to the inner cavity. The flagella of the cells lining the channels create a flow of water in them directed to the central cavity. Water brings with it tiny particles of food - protozoa, pieces of algae, eggs and larvae. Water and undigested residues exit through the mouth, a large opening usually located at the top of the sponge.

Purely!
In an hour, a large sponge can filter the volume of water equal to the volume of the bath. Sponges are indispensable components of aquatic ecosystems, keeping water clean.

Toilet sponges.
Nowadays, most sponges for washing are made from artificial materials. But many years ago they were collected at sea. An ordinary toilet sponge lives at the bottom of the sea in clean, warm water. It is rather slippery, yellow or purple in color. After death, its soft parts rot, and a skeleton of fibers and needles remains, which people used as a washcloth. In some areas, such as the Mediterranean, toilet sponges were collected in such quantities that they became extremely rare. But it takes about 20 years for a sponge to grow.

How do sponges reproduce?
Sponges are able to form small specific outgrowths, or buds, on the body, which then separate and develop into a new individual. But they also have sexual reproduction. Each sponge is both a male and a female, that is, it produces both spermatozoa and eggs. The spermatozoa fertilize the eggs, and they develop into tiny larvae that spread out. Two or three days they are in the open sea, then sink to the bottom and develop into a new sponge.

How do sponges survive?
Sponges have no means of protection. They don't know how to bite or sting. They cannot swim. How do they protect themselves? The body of many sponges has many tiny, sharp needles of hard minerals such as lime, chalk, or silica (the same substance that makes up glass). The needles form the sponge's skeleton, give its body strength, and keep animals that would like to feast on the sponge at a distance. In addition, many species have an unpleasant odor and a terrible taste that repels predators.

Lamellar.
lamellar includes only one species - Trichoplax adhaerens.
These small creatures, reaching the size of an ant, resemble giant amoebas, but their body consists of more than 1000 cells. Lamellar slowly flow, moving like. Only two species are known, and both live in the sea.

Sponges
About 10,000 species
Most are marine, only a few are freshwater
Many have an internal hard skeleton
Body riddled with holes
Some reach 4 m

lamellar
Just a few types
Marine life
Move like slugs or giant amoebas
About 3 mm long