Sponge reefs

Examples of Sponge reefs in the following topics:

• Sponge Communities

  • These sponge reefs are considered to be "living fossils. "
  • There are no known predators of healthy reef sponges.
  • Each living sponge on the surface of the reef can be over 1.5 m tall.
  • The growth of sponge reefs is thus analogous to that of coral reefs.
  • This chain of sponge reefs is the largest known biostructure to have ever existed on Earth.

• Marine Habitats

  • Reefs comprise some of the densest and most diverse habitats in the world.
  • The best-known types of reefs are tropical coral reefs, which exist in most tropical waters; however, reefs can also exist in cold water.
  • Reefs are built up by corals and other calcium-depositing animals, usually on top of a rocky outcrop on the ocean floor.
  • Reefs can also grow on other surfaces; this has made it possible to create artificial reefs.
  • Coral reefs provide marine habitats for tube sponges, which in turn become marine habitats for fishes.

• Marine Biomes

  • The ocean and coral reefs make up two types of marine biomes where organisms are influenced by depth and light availability.
  • Within the ocean, coral reefs are a second kind of marine biome.
  • Due to the dead organisms that fall from the upper layers of the ocean, this nutrient-rich portion of the ocean allows a diversity of life to exist, including fungi, sponges, sea anemones, marine worms, sea stars, fishes, and bacteria.
  • Other coral reef systems are fringing islands, which are directly adjacent to land, or atolls, which are circular reef systems surrounding a former landmass that is now underwater.
  • Describe coral reefs and the various zones in the ocean and the types of organisms living in each

• Coral Reefs

• Sea Coral and Sea Anemone Zooxanthellae

  • They are also harbored by various species of sponges, flatworms, mollusks (e.g. giant clams), foraminifera (soritids), and some ciliates.
  • These dinoflagellates are therefore among the most abundant eukaryotic microbes found in coral reef ecosystems.

• Physiological Processes in Sponges

  • All cell types within the sponge obtain oxygen from water through diffusion.
  • Sponges reproduce by sexual, as well as, asexual methods.
  • Gemmules are environmentally-resistant structures produced by adult sponges wherein the typical sponge morphology is inverted.
  • Sexual reproduction in sponges occurs when gametes are generated.
  • In some sponges, production of gametes may occur throughout the year, whereas other sponges may show sexual cycles depending upon water temperature.

• Morphology of Sponges

  • In addition to the osculum, sponges have multiple pores called ostia on their bodies that allow water to enter the sponge.
  • In other sponges, ostia are formed by folds in the body wall of the sponge.
  • Choanocytes ("collar cells") are present at various locations, depending on the type of sponge; however, they always line the inner portions of some space through which water flows: the spongocoel in simple sponges; canals within the body wall in more complex sponges; and chambers scattered throughout the body in the most complex sponges.
  • Whereas pinacocytes line the outside of the sponge, choanocytes tend to line certain inner portions of the sponge body that surround the mesohyl.
  • The specialized cell types in sponges (b) each perform a distinct function.

• Phylum Porifera

  • Phylum Porifera ("pori" = pores, "fera" = bearers) are popularly known as sponges.
  • The majority of sponges are marine, living in seas and oceans.
  • There is, however, one family of fresh water sponges (Family Spongillidae).
  • Sponges are classified within four classes: calcareous sponges (Calcarea), glass sponges (Hexactinellida), demosponges (Demospongiae), and the recently-recognized, encrusting sponges (Homoscleromorpha) .
  • Since water is vital to sponges for excretion, feeding, and gas exchange, their body structure facilitates the movement of water through the sponge.

• Nerve and Blood Supply

  • The synovial cartilage in the capsule acts somewhat like a sponge.
  • A sponge will absorb fluid, but it will release little of that fluid unless it is squeezed.
  • Exercising the joint, in effect, squeezes the synovial "sponge", allowing gas exchange to occur and nutrients to flow into the cartilage.
  • Flexing and extending the joint alternately squeezes the sponge and releases it to reabsorb more fluid.

• Complex Tissue Structure

  • Animals, besides Parazoa (sponges), are characterized by specialized tissues such as muscle, nerve, connective, and epithelial tissues.
  • The animal kingdom is divided into Parazoa (sponges) and Eumetazoa (all other animals).
  • Sponges, such as those in the Caribbean Sea, are classified as Parazoans because they are very simple animals that do not contain true specialized tissues.