The crab probably came to admire the perfect skeletal structure glass sponges View of the Basket of Venus
Sea sponges are primitive organisms. These are invertebrate animals that spend almost their entire lives attached to rocks or the bottom. Sponges are found almost everywhere, from coastal zones to the deepest places in the ocean. Approximately 8,000 species of sponges are represented. They do not have real tissues and organs; their functions are performed by individual cells and layers of cells. Sponges feed by driving water through their own body. The filtrate, where small creatures and various organic particles fall, serves as food for the sponge.
There are also predatory sponges - there are about 140 species. These predators feed on crustaceans and other small animals. Sponges of the family Cladorhizidae use long sticky threads to hunt. cellular structure. When the victim is glued to the thread, it shortens, pulling the victim towards the sponge, which gradually envelops the victim and digests it. Sponges use water filtration not only to obtain food, but also to obtain oxygen for body tissues. According to experts, every day many types of sponges pump through themselves a volume of water that is 20,000 times greater than their own body volume. One of the most unusual species sponges - Cladorhizidae. These creatures can be called living fiber optics.
This sponge belongs to the class of glass sponges (six-beam sponges), which create their base from silicon dioxide. These living organisms are very beautiful, since the threads of the “skeleton” are intertwined in the most unusual combinations. Glass sponges of the phylum Cladorhizidae usually live with shrimp, which occupy the internal cavity of the skeleton. The shrimp swim inside as larvae, and after molting they remain to live inside, since they cannot pass through the cells of the glass net. The size of glass sponges reaches 20-30 centimeters.
Experts from Bell Labs were previously interested in glass sponges. Representatives of the company, having studied the fibers of the skeleton, concluded that the material is similar in structure to optical fiber. The length of the sponge fibers is 5-15 cm, and the diameter is 40-70 microns. The structure of the fibers is complex; they are multilayer objects. The center is a rod made of, in fact, quartz glass. This rod is surrounded by layers of organic matter and shell. Moreover, the shell has a special structure that makes it possible to conduct light through artificial fibers.
Specialists from Bell Labs were surprised by the fact that sponges create their fibers in water at low temperatures. Man produces optical fiber using expensive equipment at high temperatures in special ovens. According to specialist Joanna Eisenberg, sponges can be an example alternative way fiber optic production. Moreover, a feature of the material produced by sponges is its strength and flexibility. Such fibers are much less fragile and practically do not crack. They can be tied into a knot without any problems, and the optical properties of the channel will be practically unaffected. Light passes through such fibers very well, since the sponges use sodium ions when forming their glass skeleton, which improve the optical properties of the material. Naturally, sodium is added by these organisms under conditions of the same low temperature in aquatic environment. For fiber optic manufacturers, control of sodium ions in production process still poses a problem.
Bell Labs studied the structure of sponge optical fiber, finding that it consists of several layers. The optical properties of each layer are different. As mentioned above, the center of the sponge fiber is a rod of pure quartz glass. Concentric layers of glass surround the rod as the sponge grows. It is this structure that makes the fiber formed by the sponge very resistant to breaks and cracks. The individual layers are glued together using a special organic glue. As the skeleton forms, the individual fibers intertwine together to form something like a lattice.
The skeletal structure of glass sponges has much in common with the structure of buildings and structures created by humans. True, the “buildings” that the sponge creates are 1000 times smaller than most objects of this type created by man. The photo shows the Swiss Tower from London, Hotel De Las Artes from Barcelona and a structural element of the Eiffel Tower
The lattice is reinforced by a special substance (mesoglea), and the skeleton of the sponge, under the influence of mesoglea and the sheath of fibers, becomes quite strong. According to experts, such a structure is similar to that used by architects who create buildings under seismic conditions. hazardous areas. Such material can be slightly deformed, but it is very difficult to break. Evolving, sponges learned to build the strongest possible skeletons from minimum quantity material. The researchers say the sponge uses just the amount of material needed and no more.
Interestingly, sponges of the species Euplectella aspergillum (the “Venus’s Basket” already mentioned above) are attached to the bottom using elastic glass spicule needles, the diameter of which is 50 microns. Their length can reach 10 centimeters. These spicules are very strong, so it is very difficult to break them by tearing off the sponge.
Last year, scientists studying glass sponges conducted a simulation mechanical properties artificial fibers of these creatures. The goal was to find the optimal sequence of cylinder thicknesses to achieve maximum tensile strength of the skeleton. As it turned out, the calculated parameters are very close to the real ones. Sponges use a decrease in thickness from the center to the edge.
Joanna Eisenberg argues that the glass sponge skeleton is one of the best solutions in mechanical engineering. Perhaps this material can help humans discover new possibilities in materials science and improve engineering design. This structure is very complex, this applies to both individual fibers and the entire skeleton as a whole. “This baffles me. I can’t imagine how sponges form their skeleton from individual fibers, creating almost perfect structures,” Eisenberg said. Scientists now suggest that in the center of each fiber during its formation there is a protein that plays important role in the creation of both the core and the entire optical fiber as a whole.
"It's amazing how many engineering construction techniques use sponges to create the skeleton," says James Weaver, a scientist at the University of California, Santa Barbara.
Target: study the type of sponge as the first multicellular animals.
Tasks:
- consider the history of the appearance of sponges, their diversity and significance;
- attract students' attention to a little-studied group of animals;
- introduce the variety of sponges.
Equipment: tables on the classification of sponges, presentation “Sponges”. Video fragment: “Regeneration of sponges.”
Basic terms and concepts: multicellularity, cell differentiation, choanocytes, biofilters, regeneration, symbiosis. A systematic approach to developmental training was used.
DURING THE CLASSES
I. Organizational moment
Students' mood for the lesson.
II. Check of knowledge
Instead of dots, choose the appropriate words
Option 1.
- Amoebas move using...
- The food composition of ciliates - slippers mainly includes...
- In freshwater protozoa, metabolic products and excess water are excreted through...
- The reactions of protozoa to stimuli are called...
- Green euglenas... react to light.
- When advancing unfavorable conditions Most protozoa go into a state...
- The disease is caused by malaria when it enters the blood...
Option 2.
III. Teacher's story:
1. The history of the discovery of sponges
How much do we know about sponges? And most textbooks mention sponges somewhat casually, not in great detail and, it seems, not very willingly. What is the matter, why was a whole type of animal, quite numerous and widespread, so unlucky?
Zoologists still don’t know exactly where, in what part of the animal kingdom to place sponges. Either these are colonies of protozoa, that is, unicellular organisms, or primitive, but still multicellular animals. And sponges received the status of animal organisms only in 1825, and before that they, along with some other sessile animals, were classified as zoophytes - half-animals, half-plants.
Calcareous sponges have been known since the Precambrian, glass sponges since the Devonian. Currently, most researchers, following Ivan Mechnikov, consider a hypothetical animal, the phagocytella, as the ancestor of sponges. This is evidenced by the structure of the sponge larvae, which is close to the most archaic animals from the subkingdom of phagocytelliformes - trichoplaxes.
However, Haeckel believed that sponges evolved from collared flagellates, in whose colonies anatomical and functional differences arose.
Sponges turned out to be a blind branch of evolution; no one descended from them.
2. Multicellular animals - sponges
– Guess what features sponges will have in contrast to protozoa? Use paragraph 5 of the textbook, page 22. Write down the features in your notebook.
Teacher's additions:
1. The presence of choanocyte cells or collar cells with flagella, the beating of which creates a flow of water necessary to supply the body with food and oxygen and to remove carbon dioxide and metabolic products. Choanocytes of some complex sponges are capable of “pumping” a volume of water every minute equal to the volume of the sponge itself.
Cross section through the wall of the sponge body 1 – mouth, 2 – body cavity, 3 – channels
2. The body consists mainly of a gelatinous substance, inside of which there is a skeleton of protein, calcium carbonate or silica. Sponges belong to the cellular level of organization
3. Sponges already have cell differentiation, but there is still no or almost no coordination between cells necessary for organizing them into tissues.
4. The cells form a very loose, fragile complex, and if you rub a sponge through a silk sieve, the connections between them can be completely disrupted, although the cells themselves are not damaged. The cells can then unite again into a complex similar to the original one.
5. Since sponges have a number of unique morphological features characteristic only of this type, they are usually considered a side branch of the evolutionary trunk of multicellular animals. They evolved from flagellates independently of other Metazoa and did not give rise to any other phylum.
6. Living sponges resemble a piece of raw liver; They usually have a dirty brown color, a slimy surface and an unpleasant odor.
7. Sponges are sessile organisms of various sizes from 1 cm to 2 m in height; they may form a flat growth, may be spherical, fan-shaped, or have the shape of a bowl or vase.
Three types of sponge body structure: the dark stripe indicates the choanocyte layer
8. Most sponges are hermaphrodites. Reproduction is sexual and asexual. Asexual reproduction occurs by budding, sometimes internally. The buds that form on the body, as a rule, are not separated from the mother’s body, which leads to the appearance of colonies of the most bizarre shape.
9. During the sexual process, a sperm fertilizes an egg; A larva emerges from the egg, floats in the water for some time, and then attaches itself to the bottom.
10. When the larvae transform into adult sessile forms, the germ layers of sponges are distorted: the outer flagellar cells migrate inward, and the cells of the inner layer move outward.
11. Sponges respond slowly and weakly to various irritations, since there are no nerve cells in their body.
12. The receipt of oxygen and the release of dissimilation products occurs through the internal and external surfaces of the body.
13. Digestion, like that of protozoa, is intracellular.
14. Substances decomposed as a result of digestion partially diffuse into other cells and are absorbed there, and are partially assimilated in place.
VI. Did you know?
History of sponge use
1. Toilet sponge in ancient Rome.
Toilet paper The ancient Romans did not know; instead they used a simple device - an ordinary Mediterranean sponge on a stick.
A little about the sponge. It is a marine invertebrate animal whose skeleton consists of silica, or silica and spongin, or spongin alone. This skeleton has been used by people since ancient times.
Toilet sponge
When dried, it is hard and brittle, but when wet, the sponge becomes soft and holds water well. In addition, due to the presence of antiseptic substances in tissues, the sponge has bactericidal properties
The “life” of a bath sponge in modern conditions for one owner is a couple of months. Sponges are still a commercial item, and in the markets of almost all Mediterranean countries you can see sponges lying around.
Judging by the testimony of contemporaries, sponges were in common use (it would be strange to imagine a Roman carrying a personal sponge into a public toilet). In the toilet room there was usually a vessel - a bucket or basin, often made of stone, in which there were several sponges. It is suggested that before and after use it should be washed in a small channel of running water, which was usually located in the center of the toilet. In a decent toilet, a attendant looked after the sponges.
Small private toilet in the bath complex of a Roman villa
1) Sponges provide an extremely convenient refuge for other organisms, and whole line small aquatic inhabitants use their pores as homes. Here it is necessary, first of all, to name the larva of the lacewing - Sisyra fuscata, which is 4.5 mm in length, black-brown in color. In addition, sponges provide shelter to some species of caddisflies (Hydropsyche ornatula), chironomids (Glyptotendipes), water mites (Unionicola crassipes), etc. Some species of ciliates and rotifers are permanent commensalists of sponges. Sometimes sponges live in close cohabitation with bryozoans, and these organisms even germinate each other.
2) Sponges are active biofilters; some of them are capable of passing tens and hundreds of liters of water per day through their bodies.
3) It happens that sponges, growing in water bodies, cause some, albeit small, harm.
4) It was observed that they clogged the openings of water pipes and thus disrupted the operation of waterworks.
5) The bottoms of wooden ships can become overgrown with sponges, which impedes their speed of movement.
6) In fish ponds, thistle is considered undesirable. When it develops strongly, it spoils the water, giving it bad smell and taste.
2. Bodyaga sponge is used in medicine.
A person who comes into contact with a sponge may develop severe itching and mild swelling of the fingers, possibly due to the histamine-like effect of the extract from the sponge.
Finally, let's mention the Japanese. They, as always, “ahead of the rest”, started toilet sponge plantations, and those who came up with such a good idea clearly made the right decision. They make good money.
VII. Checking your understanding of the material. Completing the crossword
1. Deep-sea forms of sponges up to 50 cm high. Skeletal spines contain silicon. Body color is white, gray, yellow or brown.
2. Natural, correct location parts of the body relative to the center in multicellular animals.
3. Sponges with a calcareous skeleton, living in the shallow waters of seas and oceans. The color is yellow-gray.
4. The way of life of the animal when it is fixedly attached to the substrate (rock bottom or large object).
5. A sponge used by humans in medicine to treat rheumatism, bruises, and bruises.
6. Sponges with a silicon skeleton. The coloring is varied. They can reach sizes up to 1 meter.
7. Unicellular algae, found in the cytoplasm of sponges and providing it with oxygen.
8. Cells that perform an individual function.
9. Skeletal formations present in the gelatinous substance of the body of sponges.
Internet resources:
Original news:
Literature:
- N. Green, W. Stout, D. Taylor. Biology, vol.1. – M.: Mir, 1996.
- V.A. Dogel. Zoology of invertebrates. – L.: graduate School, 1983.
- V.A. Dogel. Well comparative anatomy invertebrates. – L.: Leningrad University, 1967.
- V. M. Koltun. Animal life, vol. 1, M., 1968
- A.A Yakhontov. Zoology for teachers publishing house "Prosveshchenie". Moscow 1968
- Basics of paleontology. Sponges, archaeocyaths, coelenterates, worms, M., 1962;
This living organism is unique in its age. The Antarctic sponge is the longest-lived of long-livers. It is possible that sponges grow very slowly due to low temperatures. Their metabolism is slow.
Scientists have discovered that the oldest Antarctic sponge is more than one and a half thousand years old. Now imagine for a moment how many interesting things this sponge has seen in its lifetime. It is these living creatures that hold the record for longevity in the animal world.
Sponges for giants and dwarfs. Slide 11
Among the primitive marine animals - sponges - the highest is Neptune's cup.
The “height” of this sedentary, truly goblet-like creature can reach 120 centimeters. But the heaviest sponge was found in the Bahamas. She had a girth of almost two meters and weighed 41 kilograms. True, after it was dried, the weight of the sponge became much smaller - only 5 kg 440 g. Well, even Thumbelina, perhaps, could not wash herself with the smallest sponge: its diameter is only 3 mm.
Neptune cup sponge Swarczewski papyrus 1-4 mm.
The body is cylindrical, up to 30 cm long, and consists of hexagonal needles, which contain silica. Deep-sea view of the tropical Pacific and Indian oceans.
In Japan, Euplectella is associated with the wedding ceremony. When young people get married, they receive a beautiful translucent basket with a pair of dried shrimps inside as a gift. The Japanese have long noticed that in each such sponge there live two shrimp - a male and a female. They get there at the larval stage and, when they grow up, they can no longer leave it. Therefore, the gift has a symbolic meaning for the newlyweds - it serves as the personification of constant love, fidelity and long-term marital happiness. Translated from Japanese, the sponge is called “to live, grow old and die together.”
Basket of Venus
Few zoologists study sponges. This can be explained simply - big practical significance they do not have, are unattractive in appearance, not like, for example, birds, tigers or sea stars. At the same time, the name of one of the largest Russian specialists in sea sponges everyone knows. Nowadays, few people remember that the great Russian traveler, ethnographer and anthropologist Nikolai Nikolaevich Miklouho-Maclay was a zoologist by training. A student and assistant of the great Ernst Haeckel, he worked a lot on the sponges of our seas. At the end of many scientific names sponges living in northern seas, we meet the name of the author of the species description – Miclucho-Maclay.
Kalymnos. Sponge divers.
Kalymnos is a fairly small island in the Aegean Sea, part of a group of over 50 Dodecanese islands in southern Greece. Although sponge diving has been a source of income for many Greek islands in recent centuries, Kalymnos is known as the center of the Greek sponge industry. The waters around the Greek islands are favorable for their growth due to the high water temperature. The best quality sponges were in the south Mediterranean Sea. It is not known exactly when the sponge came into use. In ancient writings (Plato, Homer) a sponge is mentioned as an object for washing. In Kalymnos, sponge diving also dates back to ancient times. This is one of the oldest professions on the island. Sponge diving brought social and economic development to the island. In the past, diving was done using the skin diving method. The team went out to sea on a small boat. To search for sponges at the bottom, a cylindrical object with a glass bottom was used. As soon as there was a sponge, the diver took it out from the bottom. He usually carried a 15 kg flat stone, known as a "skandalopetra", in order to quickly reach the bottom. The cut sponge was collected in special nets. The depth and time of the dive depended on the size of the diver's lungs. Although it was quite difficult to obtain this way, a lot of sponges were obtained and sold this way. Many merchants on Kalymnos became very rich. Since 1865 there has been a boom in the sponge trade. The reason for this was the introduction of a standard diving suit or Spacesuit as the Greeks called it. A merchant from the island of Symi brought equipment, probably Sibe Gorman. The advantages were obvious. Now, divers could stay as long as they wanted and for great depths. The best sponges were found at a depth of about 70 meters. The diver could now walk along the bottom and look for them.
In 1868 the sponge diver fleet consisted of:
300 ships with divers (from 6 to 15 divers on each ship) 70 ships that caught sponges with harpoons.
With the advent of the suit, trade experienced enormous growth. From Kalymnos, ships left for the Aegean and Mediterranean seas. They went as far as Tunisia, Libya, Egypt, Syria. They were at sea for 6 months.
The profit from the extraction and sale of sponges was high. For divers, there were working conditions in the suit. However, there was great danger during diving – decompression illnesses. Soon after the introduction of the suit, the first accidents with divers occurred. The symptoms, severe pain, paralysis and death were ultimately terrifying for the divers and other crew as they had no idea what was causing it all!
Daily dives to 70 meters or more and ascents without safety stops had a devastating effect: in the first year of use of the suit, about half of the divers were paralyzed or died from decompression sickness. Between 1886 and 1910, about 10,000 divers died and 20,000 were disabled.
It had big influence for all residents of Kalymnos. Each family had fathers, children, brothers and other relatives who were paralyzed or did not return from the season. Towards the end of the 19th century this caused great unrest in Kalymnos, especially among women. At that time the island was occupied by the Turks. The women asked the Turkish Sultan to ban the spacesuit, which he did in 1882. Profits fell, divers returned to the old method of mining (skin diving). After about 4 years, the suit began to be used again and new accidents occurred.
Modern sponge mining
Most wide application from ancient times to the present day, they have toilet sponges, the skeleton of which is devoid of mineral needles. The fishery for toilet sponges is carried out in temperate, subtropical and partly tropical seas. great depth.
The diver lifts the sponge from a rock or other substrate and places it in a net, which is then lifted with a rope into the boat. Sometimes a dredge or an iron grapple is used, but with this method of extraction many sponges are damaged.
VIII. Advance homework: repeat § 5, find Interesting Facts according to the “Coelenterate” type.
So unusual and self-explanatory name the sponge deserves it appearance. Sea sponges in general are very amazing and not like anyone similar creatures.
Looking at the photo called “Venus’s basket”, you can immediately understand that this animal is the object of dreams of many collectors.
The unusual skeleton looks like a lace veil, as if enveloping this ephemeral creature. On the other hand, the sponge looks like a wicker basket. You can compare this creature with anything for a long time, one thing is for sure - this animal is unique in its kind.
The first information about this sponge appeared in 1841. In those distant times, the English naturalist Richard Owen was conducting research on the fauna of the Philippine Islands and accidentally came across an unusually beautiful sea creature. This was Euplectella aspergillum.
These living organisms, as a species, are rightfully considered one of the longest-livers of our planet, because the appearance of the ancestors of “baskets” on Earth is dated back to 420 - 440 million years ago.
Where do sponges called Venus baskets live?
These creatures can be found in western waters Pacific Ocean and in the eastern regions of the Indian Ocean.
Venus baskets prefer to settle in tropical areas. There are especially many of them near the Philippine Islands.
What is the difference between the basket of Venus and other representatives of sponges?
These animals are shaped like a vessel woven from airy threads. Externally, the sponge looks like a fragile basket. The animal's skeleton is based on a silicon composition. It consists of many ray needles, which is why the sponge belongs to the glass class - after all, its skeleton is as if invisible, and instead of it there is only “delicate lace”.
Nutrition and lifestyle of the basket of Venus
Representatives of this species prefer to lead single image life. Basket colonies are rather an exception to the rule. They settle at great depths, attaching themselves to stones and other underwater substrates. They lead a mostly sedentary lifestyle.
The basket of Venus feeds on a variety of microorganisms, as well as organic remains. The sponge pushes food through its body, thereby supplying the body with nutrients.
Beneficial properties of sponges for humans and for the world of science
Oddly enough, but such primitive, at first glance, creatures serve as an indispensable support for science, in particular physics. Scientists around the world have concluded that glass sponges (and specifically Venus baskets) are an example for creating a new generation of optical fiber.
Looking at these bottom dwellers, scientific minds are trying to adopt the ability to build a skeleton from silicon at record low temperatures(after all, at great depths the temperature ranges from 2 to 10 degrees).
The body is cylindrical, up to 30 cm long, and consists of hexagonal needles, which contain silica. Deep sea species tropical zone Pacific and Indian oceans.
In Japan, euplectella is associated with wedding ceremony. When young people get married, they receive a beautiful translucent basket with a pair of dried shrimps inside as a gift. The Japanese have long noticed that in each such sponge there live two shrimp - a male and a female. They get there at the larval stage and, when they grow up, they can no longer leave it. Therefore, the gift is for the newlyweds symbolic meaning- he serves as a personification constant love, fidelity and long marital happiness. Translated from Japanese, the sponge is called “to live, grow old and die together.”
Basket of Venus
Few zoologists study sponges. This is explained simply - they do not have much practical significance, they are unattractive in appearance, not like, for example, birds, tigers or starfish. At the same time, the name of one of the largest Russian specialists in sea sponges is known to everyone. Nowadays, few people remember that the great Russian traveler, ethnographer and anthropologist Nikolai Nikolaevich Miklouho-Maclay was a zoologist by training. A student and assistant of the great Ernst Haeckel, he worked a lot on the sponges of our seas. At the end of many scientific names of sponges living in the northern seas, we find the name of the author of the description of the species - Miclucho-Maclay.
End of work -
This topic belongs to the section:
Sponges. Classes: limestone, glass, ordinary
This lesson is carried out after studying the type of Protozoa and is a lesson according to the program V V Pasechnik's textbook V V Latyushin V A Shapkin M.. Biology lesson in the class on the topic.. Sponges Classes lime glass ordinary..
If you need additional material on this topic, or you did not find what you were looking for, we recommend using the search in our database of works:
What will we do with the received material:
If this material was useful to you, you can save it to your page on social networks:
| Tweet |
All topics in this section:
Cross section through the wall of the sponge body 1 - mouth, 2 - body cavity, 3 - channels
2. The body consists mainly of a gelatinous substance, inside of which there is a skeleton of protein, calcium carbonate or silica. Sponges belong to cellular level of organization 3.
Three types of sponge body structure: the dark stripe indicates the choanocyte layer
8. Most sponges are hermaphrodites. Reproduction is sexual and asexual. Asexual reproduction occurs through budding, sometimes internal. The buds that form on the body are usually not a part of
Where is the sponge used?
History of sponge use 1. Toilet sponge in ancient Rome. The ancient Romans did not know toilet paper; instead they used a simple device - ordinary Mediterranean paper.
Http://biouroki.ru/crossword/biologiya-7-klass-latushin/gubki.html
1. Deep-sea forms of sponges
Symbiosis of sponges with other organisms
Many animals found on the surface and inside sponges enter into harmless or mutually beneficial relationships with them. These are many crustaceans, some polychaete worms(polychaetes)
Hermit crab with cork sponge
It should be emphasized that the biological relationships between crustaceans and sponges are very diverse. There are about 500 different cases of more or less close connections, which are considered to be
Dromia crab
Some crabs playfully exploit the unattractiveness of sponges to predators. They carry pieces of sponges on their backs, supporting them with their hind limbs. Such Dromia crabs are cut with their claws according to
Sponge mining
Kalymnos. Sponge divers. Kalymnos is a fairly small island in the Aegean Sea, part of a group of over 50 Dodecanese islands in southern Greece. Although diving for sponges was the source
This group includes glass sponges, in which the microsclera are represented by various hexasters. Often the large needles of these sponges, connecting with each other, form a skeleton in the form of a spatial lattice.
Characteristic representatives of the detachment:
basket of Venus(family Euplectellidae), having a cylindrical body, large goblet-shaped
or saccular Ross sponges(family Rossellidae)
And colonial sponges from the family. Euretidae, the body of which is formed by branched and unevenly fused thin-walled tubes.
Some glass sponges have a very beautiful and graceful skeleton. Cleared of organic matter The skeleton of such sponges is used as decoration and souvenirs.
The already mentioned sponge is especially beautiful basket of Venus(Euplectella). Her skeleton looks like a delicate openwork cylinder of such an intricate and delicate structure that it seems to have been made by a skillful human hand. They say that the first copy of this sponge, brought to Europe, was bought for the fabulous sum of 600 marks. And to this day, the basket of Venus is considered a very valuable decoration.
Another glass sponge hyalonema(Hyalonema), has a rounded body sitting at the end of a rod of very long thick needles. The skeleton of this sponge is used as a whole or its individual parts are glued together into fancy artificial decorations.
The fishery for both of these sponges is concentrated mainly off the coast of Japan and the Philippine Islands. The extraction of glass sponges is fraught with great difficulties, since they live at considerable depths and have a very fragile skeleton.
Order Amphidiscophora
The sponges of this order contain microsclera in the form amphidisks, whereas hexasters are completely absent from their skeleton.
A typical representative of the squad is sponge hyalonema(family Hyalonematidae), has a goblet-shaped or oval body sitting on a long bunch of needles, with the help of which the sponge takes root in the ground.
This also includes giant sponge monoraphy(Monorhaphis chuni), having a strongly spongy cylindrical body about 1 m in height, which is pierced in the form of an axis by a needle reaching a length of 3 m with a thickness of 8.5 mm.
Loading...
