The most significant aspect of this Convention is the development of the World Heritage List. Natural heritage encompasses physical and biological formations of outstanding universal value for aesthetic or scientific reasons; geological and physiographical formations and the habitat of threatened species of animals and plants of outstanding value for scientific or conservation reasons; and natural sites of outstanding universal value from the point of view of science, conservation or natural beauty Article 2.
Arthropods - Arthropoda Invertebrates Overview of marine invertebrates tremendously diverse, ranging from microscopic wormlike mezozoans to huge animals such as the giant squid. Invertebrates are important as parasites and are essential elements of all ecological communities.
Porifera - Sponges Porifera is an animal phylum consisting of the organisms commonly called sponges. It is the only phylum of the animal subkingdom Parazoa and represents the least evolutionarily advanced group of the animal kingdom. All adult sponges are sessile nonmotileand nearly all are marine; there are four families of freshwater sponges.
Sponges lack organs and tissue, and all the cells exhibit considerable independence. The sponge is made up of two single-cell-deep layers and an intermediate mesohyl mobile cells plus extracellular matrix.
The outer sac layer consists of flattened polygonal cells called pinacocytes. The inner layer consists of flagelled cells called collar cells, or choanocytes.
The body is permeated by numerous pores called ostia that open into inhalant canals that lead to the feeding chambers, which are made up of choanocytes; here also are large openings, termed oscules, fed by exhalant canals, that carry the water current from the choanocyte chambers to the exterior.
The concerted whipping action of the choanocyte flagella creates a current of water from ostia through the sponge body oscules.
The choanocytes filter plankton and small bits of organic detritus from the water and, like the pinacocytes, absorb oxygen. Food is digested in ameboid archaeocytes that pick up food vacuoles from the choanocytes, which ingest the mainly particulate food.
Waste products are carried out through the osculum. Sponges are limited in size by the rate at which water can flow in and out of the spongocoel, bringing in food-bearing water and oxygen and removing waste products. Because the asconoid type has the smallest surface area, sponges of this structure are among the smallest in the phylum; leuconoid sponges, with a large amount of surface area, represent some of the largest members of the phylum.
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Pieces of sponge are able to regenerate into whole new sponges. Asexual reproduction occurs by budding or by fragmentation. The buds may remain attached to the parent or separate from it, and each bud develops into a new individual. Freshwater sponges, as well as several marine species, form resistant structures called gemmules that can withstand adverse conditions such as drying or cold and later develop into new individuals.
Gemmules are aggregates of sponge tissue and food, covered by a hard coating containing spicules or spongin fibers. Sexual reproduction also occurs. Most sponges are hermaphroditic, the same individual producing eggs and sperm, but in some species the sexes are separate.
The larvae are flagellated and swim about freely for a short time. After settling and attaching to a suitable substrate, the larvae develop into young sponges. Cnidarians are radially symmetrical. The mouth, located at the center of one end of the body, opens into a gastrovascular cavity, which is used for digestion and distribution of food; an anus is lacking.
Cnidarians are further characterized by having a body wall composed of three layers:In global assessments of freshwater invertebrates and marine invertebrates, 30–34% were considered Data Deficient highlighting the paucity of information for making such assessments.
Marine natural products have attracted the attention to biologists and chemists all over the world for the last five decades. Approximately 16, marine natural products have been isolated from marine organisms and reported in approximately 6, publications as of date.
Marine invertebrates comprise many groups of different organisms and occur from the sea surface to the seafloor and into the substrate. They represent the vast majority of marine biodiversity and include, for example, sponges, corals, bluebottles, worms, shells, sea urchins, starfish, crustaceans, sea cucumbers and nudibranchs.
The Mn assay has featured significantly in marine invertebrate studies and has been applied mainly to different species of bivalve exposed under both field and laboratory conditions (Majone et al., Summary of SCGE results obtained using cells from a marine bivalve and two mammalian species.
Overview of the Conservation of Australian Marine Invertebrates - Report for Environment Australia - Australian Museum, Sydney, Australia. Current Page: caninariojana.com | Invertebrates | Overview ** Andrew Rader Studios does not monitor or review the content available at external web sites.
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