FACTOID # 30: If Alaska were its own country, it would be the 26th largest in total area, slightly larger than Iran.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Sea sponge
Wikipedia:How to read a taxobox
How to read a taxobox
Sponges
Fossil range: Neoproterozoic - Recent

Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Porifera
Grant in Todd, 1836
Classes

Calcarea
Hexactinellida
Demospongiae The Neoproterozoic is the geological era from 1000 Ma to 542 Ma (million years ago). ... Marine sponge. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Digimon, the only known animals. ... Robert Edmond Grant (1793-1874), born in Edinburgh and educated at Edinburgh University as a doctor, became one of the foremost biologists of the early 19th century at Edinburgh and subsequently a professor at London University, particularly noted for his influence on Charles Darwin. ... Robert Bentley Todd (1809-1860) was a physician who is best known for describing the condition postictal paralysis in his Lumleian Lectures in 1849 now known as Todds palsy. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Orders Subclass Calcinea Clathrinida Leucettida Murrayonida Subclass Calcaronea Baerida Leucosolenida Lithonida Sycettida The calcareous sponges of class Calcarea are members of the animal phylum Porifera, the cellular sponges. ... LOSER sponges are sponges with a skeleton made of four- and/or six-pointed silaceous spicules, often referred to as glass sponges. ... Demosponges are the largest class of Phylum Porifera. ...

The sponges or poriferans (from Latin porus "pore" and ferre "to bear") are animals of the phylum Porifera. They are primitive, sessile, mostly marine, water dwelling, and filter feeders that pump water through their bodies to filter out particles of food matter. Sponges represent the simplest of animals. With no true tissues (parazoa), they lack muscles, nerves, and internal organs. Their similarity to colonial choanoflagellates shows the probable evolutionary jump from unicellular to multicellular organisms. There are over 5,000 modern species of sponges known, and they can be found attached to surfaces anywhere from the intertidal zone to as deep as 8,500 m (29,000 feet) or further. Though the fossil record of sponges dates back to the Neoproterozoic Era, new species are still commonly discovered. Latin was the language originally spoken in the region around Rome called Latium. ... Digimon, the only known animals. ... For the linguistic term, see Phylum (linguistics). ... Look up sessile in Wiktionary, the free dictionary. ... The worlds oceans as seen from the South Pacific Ocean, before the definition of the Southern Ocean in 2000 For other uses, see Ocean (disambiguation). ... Filter feeders (also known as suspension feeders) are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized structure, such as the baleen of baleen whales. ... This article or section is in need of attention from an expert on the subject. ... This article is about the animal. ... Bold text == A top-down view of skeletal muscle Muscle (from Latin musculus little mouse[1]) is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... Nerves (yellow) Nerves redirects here. ... In biology, an organ (Latin: organum, instrument, tool) is a group of tissues that perform a specific function or group of functions. ... The choanoflagellates are a group of flagellate protozoa. ... A microorganism or microbe is an organism that is so small that it is microscopic (invisible to the naked eye). ... Multicellular organisms are those organisms containing more than one cell, and having differentiated cells that perform specialized functions. ... A rock, seen at low tide, exhibiting typical intertidal zonation. ... The metre, or meter (U.S.), is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Three small ammonite fossils, each approximately 1. ... The Neoproterozoic is the geological era from 1000 Ma to 542 Ma (million years ago). ...

Contents

Anatomy

Sponges have several cell types:

  • Choanocytes (also known as "collar cells"), flagellated cells that function as the sponge's digestive system, are remarkably similar to the protistan choanoflagellates. The collars are composed of microvilli and are used to filter particles out of the water. The beating of the choanocytes’ flagella creates the sponge’s water current.
  • Porocytes are tubular cells that make up the pores into the sponge body through the mesohyl.
  • Pinacocytes which form the pinacoderm, the outer epidermal layer of cells. This is the closest approach to true tissue in sponges
  • Myocytes are modified pinacocytes which control the size of the osculum and pore openings and thus the water flow.
  • Archaeocytes (or amoebocytes) have many functions; they are totipotent cells which can transform into sclerocytes, spongocytes, or collencytes. They also have a role in nutrient transport and sexual reproduction.
  • Sclerocytes secrete calcareous or siliceous spicules which reside in the mesohyl.
  • Spongocytes secrete spongin, collagen-like fibers which make up the mesohyl.
  • Collencytes secrete collagen.
  • Spicules are stiffened rods or spikes made of calcium carbonate or silica which are used for structure and defense.
  • Cells are arranged in a gelatinous non-cellular matrix called mesohyl.

Sponges have three body types: asconoid, syconoid, and leuconoid. Choanocytes (also known as collar cells) are cells that line the interior body walls of sponges that contain a central flagellum surrounded by a collar of microvilli. ... For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and... Typical phyla Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: ) are a diverse group of organisms, comprising those eukaryotes that are not animals... The choanoflagellates are a group of flagellate protozoa. ... A microvillus (usually not occurring alone, so usually referred to as the plural microvilli) is a small (0. ... A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ... Porocytes are tubular cells which make up the pores of a sponge. ... The mesohyl, formerly knowen as mesenchyme, is a gelatinous matrix within a sponge. ... Pinacocytes are epidermal cells which make up the pinacoderm in sponges. ... The Pinacoderm is the outer most layer of cells (pinacocytes) in the Phylum Porifera (sponges) , equivalent to the epidermis in other organisms. ... Totipotency is the ability of a single cell, usually a stem cell, to divide and produce all the differentiated cells in an organism, including extraembrionic tissues. ... Sclerocytes are spicule secreting cells, found in sponges. ... Sclerocytes are spicule secreting cells, found in sponges. ... Calcareous formed from or containing a high proportion of Calcium carbonate. ... This page is a candidate to be copied to Wiktionary. ... This article is about the skeletal structure. ... A horny, sulfur-containing protein related to keratin that forms the skeletal structure of certain classes of sponges (American Heritage Dictionary, 2006) Proteinaceous comounds of which the spicules in Demospongiae are composed (Cartage, 2006) ... Tropocollagen triple helix. ... Tropocollagen triple helix. ... Spicules are skeletal structures that appear in some types of sponges. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ... R-phrases R42 R43 R49 S-phrases S22 S36 S37 S45 S53 Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... In biology, the word matrix is used for the material between animal or plant cells, or generally the material (or tissue) in which more specialized structures are embedded, and also specifically for one part of the mitochondrion. ... Asconoid is one of three possible body plans for sponges, which form the phylum Porifera in kingdom Animalia. ...


Asconoid sponges are tubular with a central shaft called the spongocoel. The beating of choanocyte flagella forces water into the spongocoel through pores in the body wall. Choanocytes line the spongocoel and filter nutrients out of the water. A spongocoel is the large, central cavity of the animals in Phylum Porifera. ...


Syconoid sponges are similar to asconoids. They have a tubular body with a single osculum, but the body wall is thicker and more complex than that of asconoids and contains choanocyte-lined radial canals that empty into the spongocoel. Water enters through a large number of dermal ostia into incurrent canals and then filters through tiny openings called prosopyles into the radial canals. There food is ingested by the choanocytes. Syconoids do not usually form highly branched colonies as asconoids do. During their development, syconoid sponges pass through an asconoid stage. Scale model of Portus, near Ostia The Temple of the goddess Roma on the Forum of Ostia. ...


Leuconoid sponges lack a spongocoel and instead have flagellated chambers, containing choanocytes, which are led to and out of via canals.


Physiology

A marine sponge (compare color corrected version).
A marine sponge (compare color corrected version).

Sponges have no true circulatory system; however the water current is used for circulation. Dissolved gases are brought to cells and enter the cells via simple diffusion. Metabolic wastes are also transferred to the water through diffusion. Sponges pump remarkable amounts of water. Leuconia, for example, is a small leuconoid sponge about 10 cm tall and 1 cm in diameter. It is estimated that water enters through more than 80,000 incurrent canals at a speed of 6cm per minute. However, because Leuconia has more than 2 million flagellated chambers whose combined diameter is much greater than that of the canals, water flow through chambers slows to 3.6cm per hour. Such a flow rate allows easy food capture by the collar cells. All water is expelled through a single osculum at a velocity of about 8.5 cm/second: a jet force capable of carrying waste products some distance away from the sponge. Marine sponge. ... Marine sponge. ... based on Image:Sponge. ... Osculum is a large opening to the outside, in which the current of water exits after passing through the large cavity (spongocoel) of a sponge. ...


Sponges have no respiratory or excretory organs; both functions occur by diffusion in individual cells. Contractile vacuoles are found in archaeocytes and choanocytes of freshwater sponges. The only visible activities and responses in sponges, other than propulsion of water, are slight alterations in shape and closing and opening of incurrent and excurrent pores, and these movements are very slow. Schematic of typical animal cell, showing subcellular components. ... Archaeocytes or ameobocytes (from Greek archaios beginning and kytos hollow vessel) are amoeboid cells found in sponges. ... Choanocytes (also known as collar cells) are cells that line the interior body walls of sponges that contain a central flagellum surrounded by a collar of microvilli. ...


Taxonomy

Sponges are one of the most primitive multicellular animals, and as such, lack many of the typical features of animals including nerves and locomotion. Because of this they were placed in the group Parazoa, considered a sister taxon to all higher animals (Eumetazoa). However the latest DNA evidence shows that sponges are basal to all Metazoans.[1] Sponges share many characteristics with colonial protists, such as Volvox, though they have a higher degree of cell specialization and interdependence. Even so, if a sponge is placed in a blender, any surviving cells can reform a complete organism. If multiple sponges are blended together, each species will recombine independently (contrast animal chimera such as the geep). subgroups Ctenophora Cnidaria Bilateria Eumetazoa is a clade comprising all major animal groups except sponges. ... Typical phyla Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: ) are a diverse group of organisms, comprising those eukaryotes that are not animals... Species Volvox aureus Volvox carteri () Volvox globator Volvox dissipatrix Volvox tertius Volvox is one of the best-known chlorophytes and is the most developed in a series of genera that form spherical colonies. ... In zoology, a chimera is an animal which has two or more different populations of genetically distinct cells that originated in different zygotes; if the different cells emerged from the same zygote, it is called a mosaicism. ... A geep is a chimera produced by combining the embryos of a goat and a sheep; the resulting animal has cells of both sheep and goat origin. ...


Sponges are divided into classes based on the type of spicules in their skeleton. The three classes of sponges are bony (Calcarea), glass (Hexactenellida), and spongin (Demospongiae). Some taxonomists have suggested a fourth class, Sclerospongiae, of coralline sponges, but the modern consensus is that coralline sponges have arisen several times and are not closely related.[2] In addition to these four, a fifth class has been proposed: Archaeocyatha. While these ancient animals have been phylogenetically vague for years, the current general consensus is that they were a type of sponge. Orders Subclass Calcinea     Clathrinida     Murrayonida Subclass Calcaronea     Leucosoleniida     Lithonida The Calcareous sponges belong to the Class Calcarea and are characterized by spicules made out of calcium carbonate (calcite). ... LOSER sponges are sponges with a skeleton made of four- and/or six-pointed silaceous spicules, often referred to as glass sponges. ... Demosponges are the largest class of Phylum Porifera. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ... Ceratoporella nicholsoni, cut specimen from Pedro Bank, Caribbean, about 15 cm wide. ... The Archeocyatha, also called Archaeocyathids, were sessile, reef-building marine organisms that lived during the Lower Cambrian period (500-600 million years ago). ...


Although 90% of modern sponges are demosponges, fossilized remains of this type are less common than those of other types because their skeletons are composed of relatively soft spongin that does not fossilize well. The fossil Archaeocyantha may also belong here, though their skeletons are solid rather than separated into spicules. It has been suggested that the sponges are paraphyletic to the other animals. Otherwise they are sometimes treated as their own subkingdom, the Parazoa. Similar fossil animals known as Chancelloria are no longer regarded as sponges. Sponges have holes throughout their bodies in addition. Demosponges are the largest class of Phylum Porifera. ... The Archeocyatha, also called Archaeocyathids, were sessile, reef-building marine organisms that lived during the Lower Cambrian period (500-600 million years ago). ... Paraphyletic - Wikipedia /**/ @import /skins-1. ... This article is about the animal. ...


One phylogenetic hypothesis based on molecular analysis proposes that the phylum Porifera is in fact paraphyletic, and that members of Porifera should be split into two new phyla, the Calcarea and the Silicarea. Paraphyletic - Wikipedia /**/ @import /skins-1. ... For the linguistic term, see Phylum (linguistics). ... Orders Subclass Calcinea     Clathrinida     Murrayonida Subclass Calcaronea     Leucosoleniida     Lithonida The Calcareous sponges belong to the Class Calcarea and are characterized by spicules made out of calcium carbonate (calcite). ... Silicarea is a proposed new phylum based on molecular studies of the phylum Porifera. ...


Geological history

Fossil sponge Raphidonema farringdonense from the Cretaceous of England
Fossil sponge Raphidonema farringdonense from the Cretaceous of England

The fossil record of sponges is not abundant, except in a few scattered localities. Some fossil sponges have worldwide distribution, while others are restricted to certain areas. Sponge fossils such as Hydnoceras and Prismodictya are found in the Devonian rocks of New York state. In Europe the Jurassic limestone of the Swabian Alps are composed largely of sponge remains, some of which are well preserved. Many sponges are found in the Cretaceous Lower Greensand and Chalk Formations of England, and in rocks from the upper part of the Cretaceous period in France. A famous locality for fossil sponges is the Cretaceous Faringdon Sponge Gravels in Faringdon, Oxfordshire in England. An older sponge is the Cambrian Vauxia. Photograph of the fossil sponge Raphidonema taken by Dlloyd. ... Photograph of the fossil sponge Raphidonema taken by Dlloyd. ... Three small ammonite fossils, each approximately 1. ... Disambiguation: Devonian is sometimes used to refer to the Southwestern Brythonic language, and the people of the county of Devon are sometimes referred to as Devonians The Devonian is a geologic period of the Paleozoic era. ... NY redirects here. ... This article is 150 kilobytes or more in size. ... // The image above is believed to be a replaceable fair use image. ... Limey shale overlaid by limestone. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... The Chalk Formations of Europe are thick deposits of chalk, a soft porous white limestone, deposited in a marine environment during the upper Cretaceous Period. ... Motto: (French for God and my right) Anthem: God Save the King/Queen Capital London (de facto) Largest city London Official language(s) English (de facto) Unification    - by Athelstan AD 927  Area    - Total 130,395 km² (1st in UK)   50,346 sq mi  Population    - 2006 est. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... The Folly, from the A420 Faringdon market place All Saints church, Faringdon Faringdon is a picturesque market town in the Vale of White Horse, near the Thames Valley in southern England, United Kingdom. ... Oxfordshire (abbreviated Oxon, from the Latinised form Oxonia) is a county in the South East of England, bordering on Northamptonshire, Buckinghamshire, Berkshire, Wiltshire, Gloucestershire, and Warwickshire. ... Motto: (French for God and my right) Anthem: God Save the King/Queen Capital London (de facto) Largest city London Official language(s) English (de facto) Unification    - by Athelstan AD 927  Area    - Total 130,395 km² (1st in UK)   50,346 sq mi  Population    - 2006 est. ... The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ... Species  ? Vauxia is an extinct genus of large sponge. ...


Fossil sponges differ in size from 1 cm (0.4 inches) to more than 1 meter (3.3 feet). They vary greatly in shape, being commonly vase-shapes (such as Ventriculites), spherical (such as Porosphaera), saucer-shaped (such as Astraeospongia), pear-shaped (such as Siphonia), leaf-shaped (such as Elasmostoma), branching (such as Doryderma), irregular or encrusting.


Detailed identification of many fossil sponges relies on the study of thin sections.


Reproduction

Sponges reproduce sexually and asexually. They can reproduce asexually by the process of budding, internal and external. External budding occurs when the parent sponge grows a bud on the outside of its body that can either break away or stay connected. Internal budding is when archaeocytes collect in the mesophyl and become surrounded by spongin. The internal bud is called a Gemmeule. An asexually reproduced sponge has exactly the same genetic material as the parent. Sponges can also perform external sexual reproduction. Although sponges are hermaphroditic (both male and female), they do not fertilize their own eggs with their own sperm, as this would be asexual reproduction. Instead, all sponges of a certain species release their eggs and sperm on a certain night, generally the full moon, and they fertilize each other in the water, producing child sponges different from either parent.


Ecology

Natural Sponges in Tarpon Springs, Florida
Natural Sponges in Tarpon Springs, Florida

Modern sponges are predominantly marine, with some 150 species adapted to freshwater environments. Their habitats range from the inter-tidal zone to depths of 6,000 metres (19,680 feet). Certain types of sponges are limited in the range of depths at which they are found. Sponges are worldwide in their distribution, and range from waters of the polar regions to the tropical regions. Sponges are most abundant in both numbers of individuals and species in warmer waters. Download high resolution version (1024x768, 249 KB)Natural Sponges in Tarpon Springs, Florida. ... Download high resolution version (1024x768, 249 KB)Natural Sponges in Tarpon Springs, Florida. ...


Adult sponges are largely sessile, and live in an attached position. However, it has been noted that certain sponges can move slowly by directing their water current in a certain direction with myocytes. The greatest numbers of sponges are usually to be found where a firm means of fastening is provided, such as on a rocky ocean bottom. Some kinds of sponges are able to attach themselves to soft sediment by means of a root-like base. Sponges also live in quiet clear waters, because if the sediment is agitated by wave action or by currents, it tends to block the pores of the animal, lessening its ability to feed and survive.


Recent evidence [1] suggests that a new disease called Aplysina red band syndrome (ARBS) is threatening sponges in the Caribbean. Aplysina red band syndrome causes Aplysina to develop one or more rust-coloured leading edges to develop their structure, sometimes with a surrounding area of necrotic tissue so that the lesion causes a contiguous band around some or all of the sponge's branch.


Skeleton as absorbent

In common usage, the term sponge is usually applied to the skeletons of these creatures alone, from which the animal matter has been removed by maceration and washing. The material of which these sponges are composed is spongin. Calcareous and siliceous sponges are too harsh for similar use. Commercial sponges are derived from various species and come in many grades, from fine soft "lamb's wool" sponges to the coarse grades used for washing cars. The luffa sponge, also spelled "loofah," commonly sold for use in the kitchen or the shower, is not related to any animal sponge but is derived instead from the locules of a pepo fruit (Cucurbitaceae). Marine sponges come from fisheries in the Mediterranean and West Indies. The manufacture of rubber, plastic and cellulose based synthetic sponges has significantly reduced the commercial sponge fishing industry over recent years. Maceration is a bone preparation technique whereby parts of a vertebrate corpse are left to rot inside a closed container at near-constant temperature, to get a clean skeleton. ... A horny, sulfur-containing protein related to keratin that forms the skeletal structure of certain classes of sponges (American Heritage Dictionary, 2006) Proteinaceous comounds of which the spicules in Demospongiae are composed (Cartage, 2006) ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... R-phrases R42 R43 R49 S-phrases S22 S36 S37 S45 S53 Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ... Species (Angled luffa, Ridged Luffa) (Smooth luffa, Egyptian luffa) (Sponge cucumber) and others A luffa sponge whose coarse texture helps with skin polishing. ... Genera Abobra Acanthosicyos Actinostemma Alsomitra Ampelosycios Anacaona Apatzingania Apodanthera Bambekea Benincasa Biswarea Bolbostemma Brandegea Bryonia Calycophysum Cayaponia Cephalopentandra Ceratosanthes Chalema Cionosicyos Citrullus Coccinia Cogniauxia Corallocarpus Cremastopus Ctenolepis Cucumella Cucumeropsis Cucumis Cucurbita Cucurbitella Cyclanthera Dactyliandra Dendrosicyos Dicoelospermum Dieterlea Diplocyclos Doyerea Ecballium Echinocystis Echinopepon Edgaria Elateriopsis Eureiandra Fevillea Gerrardanthus Gomphogyne Gurania Guraniopsis... The Mediterranean Sea is an intercontinental sea positioned between Europe to the north, Africa to the south and Asia to the east, covering an approximate area of 2. ... The Caribbean or the West Indies is a group of islands in the Caribbean Sea. ... Latex being collected from a tapped rubber tree Rubber is an elastic hydrocarbon polymer which occurs as a milky colloidal suspension (known as latex) in the sap of several varieties of plants. ... This article or section does not adequately cite its references or sources. ... Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose (C6H10O5)n is a long-chain polymeric polysaccharide carbohydrate, of beta-glucose [1][2]. It forms the primary structural component of green plants. ... Fishing is the activity of hunting for fish by hooking, trapping, or gathering animals not classifiable as insects which breathe in water or pass their lives in water. ...


Notes

References

  1. ^ Joachim Schütze, Anatoli Krasko, Marcio Reis Custodio, Sofia M. Efremova, Isabel M. Müller and Werner E. G. Müller. "[Evolutionary relationships of Metazoa within the eukaryotes based on molecular data from Porifera". Royal Society.
  2. ^ R. C. Brusca and G. J. Brusca (2003). Invertebrates. Second Edition. Sunderland, Mass.: Sinauer Associates. 

Sources

  • C. Hickman Jr., L. Roberts and A Larson (2003). Animal Diversity, 3rd, New York: McGraw-Hill. ISBN 0-07-234903-4. 
  • New disease threatens sponges, Practical Fishkeeping

External links

Find more information on Sponge by searching Wikipedia's sister projects
 Dictionary definitions from Wiktionary
 Textbooks from Wikibooks
 Quotations from Wikiquote
 Source texts from Wikisource
 Images and media from Commons
 News stories from Wikinews
 Learning resources from Wikiversity
Wikispecies has information related to:
Wikibooks
Wikibooks Dichotomous Key has more about this subject:

  Results from FactBites:
 
Marine Sponge - Fina Dalmata - Sea Sponge - Krapanj (722 words)
For a tame sponge to grow 15 centimeters in diameter (middle commercial size) a period of 2-4 years is necessary, depending on the area of growth.
While alive the sponge is covered with a dark membrane, which consists of a great number of small holes through which the sea circulates in the inside of the sponge.
The use of the sea sponge is widely spread even today, although the modern technology, with different sintectic materials, tries to beat sponges' uncatchable natural characteristics that are: firmness, endurance, possibility of absorption, characteristic of organic substance, absence of harmful static electricity (in the process of using it) and its chemical structure.
Sponges (3696 words)
Many other sponges are useless as bath sponges because their skeletons are composed of hard silica or calcium carbonate or combinations of silicious spicules and spongin, all of which would be rigid and cause scratching when used.
Fig sponges are so common on the fishing grounds of Block Island Sound that, due to their shape and clogging of nets, local fishermen contemptuously refer to them as "elephant dung." A distinctive feature of fig sponges is that their siliceous spicules include tylostyles-spicules that are pointed at one end and knobbed at the other.
Sponges are filter feeders, so their diet in captivity may include finely ground food such as that used to feed juvenile brine shrimp.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m