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Dicathais Orbita
''Dicathais'' is a genus of predatory sea snails, marine gastropod molluscs in the family Muricidae, the rock snails. This genus is monotypic; the only species in it is ''Dicathais orbita'', common name the white rock shell or cart-rut shell, found round the coasts of Australia and New Zealand. Description The white rock shell is large with a strong shell usually about long, but occasionally growing to twice this size. It shows great variation in its shell sculpture across its range. In eastern Australia there are seven to nine deeply indented ribs in each whorl with clefts of a similar width between them, sculptured with further fine riblets. This gives a fluted edge to the lip and the grooves can also be seen on the interior surface of the shell. The central column or columella is smooth and the interior of the shell is white. The western Australian form has a row of well marked nodules rather than ridges and an unindented lip while the southern Australian form has much le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island country by area, covering . New Zealand is about east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga. The country's varied topography and sharp mountain peaks, including the Southern Alps, owe much to tectonic uplift and volcanic eruptions. New Zealand's capital city is Wellington, and its most populous city is Auckland. The islands of New Zealand were the last large habitable land to be settled by humans. Between about 1280 and 1350, Polynesians began to settle in the islands and then developed a distinctive Māori culture. In 1642, the Dutch explorer Abel Tasman became the first European to sight and record New Zealand. In 1840, representatives of the United Kingdom and Māori chiefs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veliger
A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxonomic classes. It is produced following either the embryonic or trochophore larval stage of development. In bivalves the veliger is sometimes referred to as a D-stage (early in its development) or pediveliger (late in its development) larva. This stage in the life history of these groups is a free-living planktonic organism; this mode of life potentially enhances dispersal to new regions far removed from the adult mollusks that produced the larvae. The general structure of the veliger includes a shell that surrounds the visceral organs of the larva (e.g., digestive tract, much of the nervous system, excretory organs) and a ciliated velum that extends beyond the shell as a single or multi-lobed structure used for swimming and particula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrian Purple
Tyrian purple ( grc, πορφύρα ''porphúra''; la, purpura), also known as Phoenician red, Phoenician purple, royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon. It is secreted by several species of predatory sea snails in the family Muricidae, rock snails originally known by the name 'Murex'. In ancient times, extracting this dye involved tens of thousands of snails and substantial labor, and as a result, the dye was highly valued. The colored compound is 6,6′-dibromoindigo. History Biological pigments were often difficult to acquire, and the details of their production were kept secret by the manufacturers. Tyrian purple is a pigment made from the mucus of several species of Murex snail. Production of Tyrian purple for use as a fabric dye began as early as 1200 BCE by the Phoenicians, and was continued by the Greeks and Romans until 1453 CE, with the fall of Constantinople. The pigment was expensiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morula Marginalba
''Tenguella marginalba'' is a species of sea snail, a marine gastropod mollusc in the family Muricidae, the murex snails or rock snails. It is commonly known as the mulberry whelk and is found in shallow waters in the Indo-Pacific and around the north and east coasts of Australia. Description The mulberry whelk has a strong, robust shell and can grow to about but a more normal adult size is . Each body whorl has five rows of purple or blackish, roughly square, nodules separated by pale grey areas with fine sculptured vertical and horizontal lines. The lip is curved with four similar-sized ridges or teeth on its inner surface. The columella, or central axis, is white and is stout with a smooth surface. The interior of the shell is purple-grey, contrasting with the cream teeth and lip. Distribution and habitat The mulberry whelk is found on the north and east coasts of Australia and on islands in the central Indo-Pacific Ocean. In Australia, its range extends from the north wes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septifer Bilocularis
''Septifer bilocularis'' is a marine bivalve species in the family Mytilidae, the mussels. Right and left valve of the same specimen: File:Septifer bilocularis 01.jpg, Right valve File:Septifer bilocularis 02.jpg, Left valve Distribution Tropical Indo-Pacific.; also in Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma .... References * Turton W.H. (1932). Marine Shells of Port Alfred, S. Africa. Humphrey Milford, London, xvi + 331 pp., 70 pls. * Drivas, J. & Jay, M. (1987). Coquillages de La Réunion et de l'Île Maurice. Collection Les Beautés de la Nature. Delachaux et Niestlé: Neuchâtel. ISBN 2-603-00654-1. 159 pp * Kilburn, R.N. & Rippey, E. (1982) Sea Shells of Southern Africa. Macmillan South Africa, Johannesburg, xi + 249 pp. * Steyn, D.G. & Lussi, M. (1998) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mussel
Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval. The word "mussel" is frequently used to mean the bivalves of the marine family Mytilidae, most of which live on exposed shores in the intertidal zone, attached by means of their strong Byssus, byssal threads ("beard") to a firm substrate. A few species (in the genus ''Bathymodiolus'') have colonised hydrothermal vents associated with deep ocean ridges. In most marine mussels the shell is longer than it is wide, being wedge-shaped or asymmetrical. The external colour of the shell is often dark blue, blackish, or brown, while the interior is silvery and somewhat nacreous. The common name "mussel" is also used for many freshwater bivalves, including the freshwater pearl mussels. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrene Bidentata
Pyrene is a polycyclic aromatic hydrocarbon (PAH) consisting of four fused benzene rings, resulting in a flat aromatic system. The chemical formula is . This yellow solid is the smallest peri-fused PAH (one where the rings are fused through more than one face). Pyrene forms during incomplete combustion of organic compounds. Occurrence and properties Pyrene was first isolated from coal tar, where it occurs up to 2% by weight. As a peri-fused PAH, pyrene is much more resonance-stabilized than its five-member-ring containing isomer fluoranthene. Therefore, it is produced in a wide range of combustion conditions. For example, automobiles produce about 1 μg/km.Senkan, Selim and Castaldi, Marco (2003) "Combustion" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim. Reactions Oxidation with chromate affords perinaphthenone and then naphthalene-1,4,5,8-tetracarboxylic acid. Pyrene undergoes a series of hydrogenation reactions and is susceptible to halog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cronia Avellana
''Cronia avellana'' is a species of sea snail, a marine gastropod mollusk in the family Muricidae Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With about 1,600 living species, the Muricidae represent almost 10% of the Neogas ..., the murex snails or rock snails. Description Distribution References Muricidae Gastropods described in 1846 {{Muricidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunella Torquata
''Lunella torquata'', common name the twisted necklace, is a species of sea snail, a marine gastropod mollusk in the family Turbinidae, the turban snails. Description The length of the shell varies between 35 mm and 110 mm. The large, solid, umbilicate shell has an orbiculate, conic shape. It is whitish, mottled and strigate with dark brown. This species varies much in degree of elevation and carination. The six whorls show dense lamellose incremental striae and coarse spiral lirae. The upper ones are carinated, the carina becoming obsolete on the body whorl. The sutures are canaliculate, bordered below by a row of nodules. The round aperture is oblique and white within. The white columella is perforated by the wide and deep umbilicus, and with a spiral groove extending to the base. The oval operculum is flat within, with four whorls. Its nucleus is situated one-third the distance across the face. Its outside is white, excavated at the center, with two strong spira ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
