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Respiratory System Of Gastropods
The respiratory system of gastropods varies greatly in form. These variations were once used as a basis for dividing the group into subclasses. The majority of marine gastropods breathe through a single gill, supplied with oxygen by a current of water through the mantle cavity. This current is U-shaped, so that it also flushes waste products away from the anus, which is located above the animal's head, and would otherwise cause a problem with fouling. In the pulmonate gastropods, which are found on both land and in freshwater, the gill has been replaced by a simple lung. With gills With filamentous gills In gastropods in many ancient lineages, the gills are bipectinate, having an overall shape that is similar to a bird's feather, with narrow filaments projecting either side of a central stalk. Gastropods such as abalone and keyhole limpets have two gills, which is believed to be the arrangement in the earliest fossil gastropods. The water current to supply these gills is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory System
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it lives and its evolutionary history. In land animals the respiratory surface is internalized as linings of the lungs. Gas exchange in the lungs occurs in millions of small air sacs; in mammals and reptiles these are called alveoli, and in birds they are known as atria. These microscopic air sacs have a very rich blood supply, thus bringing the air into close contact with the blood. These air sacs communicate with the external environment via a system of airways, or hollow tubes, of which the largest is the trachea, which branches in the middle of the chest into the two main bronchi. These enter the lungs where they branch into progressively narrower secondary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mantle (mollusc)
The mantle (also known by the Latin word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself. In many species of molluscs the epidermis of the mantle secretes calcium carbonate and conchiolin, and creates a shell. In sea slugs there is a progressive loss of the shell and the mantle becomes the dorsal surface of the animal. The words mantle and pallium both originally meant cloak or cape, see mantle (vesture). This anatomical structure in molluscs often resembles a cloak because in many groups the edges of the mantle, usually referred to as the ''mantle margin'', extend far beyond the main part of the body, forming flaps, double-layered structures which have been adapted for many different uses, including for example, the siphon. Mantle cavity The ''mantle cavity'' is a central fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclophoridae
Cyclophoridae is a taxonomic family of small to large tropical land snails with an operculum, terrestrial gastropod mollusks in the order Architaenioglossa belonging to the subclass Caenogastropoda (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). This diverse family with many species is now limited to the representatives in the tropics and subtropics of the Old and New World. Their fossil history dates back through the Early Tertiary to the Cenomanian age of the Cretaceous. Description The dextral shells are mostly of small and rarely medium size. The form of the shell varies from discoidal to turbinate. The round aperture is often modified, sometimes with an incision or a constriction. The last whorl can sometimes be disconnected and then extends strongly from the winding plane. The operculum is generally circular, which can be retracted deeply into the shell. Its form is multispiral and can be calcified or lacking calcareous overlay. The outer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Butterfly
Sea butterflies, scientific name Thecosomata (thecosomes, "case / shell-body"), are a taxonomic suborder of small pelagic swimming sea snails. They are holoplanktonic opisthobranch gastropod mollusks. Most Thecosomata have some form of calcified shell, although it is often very light and / or transparent. The sea butterflies include some of the world's most abundant gastropod species, and because of their large numbers are an essential part of the food chain, and a significant contributor to the oceanic carbon cycle. The sea butterflies are included in the Pteropoda order, and are also included in the informal group Opisthobranchia. Morphology Sea butterflies float and swim freely in the water, and are carried along with the currents. This has led to a number of adaptations in their bodies. The shell and the gill have disappeared in several families. Their gastropodal foot has taken the form of two wing-like lobes, or ''parapodia'', which propel the animal through the sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepeta
''Lepeta'' is a genus of sea snails, the true limpets, marine gastropod mollusks in the family Lepetidae. Species Species within the genus ''Lepeta'' include: * ''Lepeta caeca'' (Müller O.F., 1776) * '' Lepeta depressa'' Hedley, 1916 ;Species brought into synonymy: * ''Lepeta albescens'' (Philippi, 1846): synonym of '' Iothia albescens'' (Philippi, 1846) * ''Lepeta antarctica'' E. A. Smith, 1907: synonym of ''Iothia antarctica'' (E. A. Smith, 1907): synonym of ''Iothia emarginuloides'' (Philippi, 1868) (original combination) * ''Lepeta caecoides'' Carpenter, 1864: synonym of ''Lepeta caeca'' (O. F. Müller, 1776) * ''Lepeta coppingeri'' (E. A. Smith, 1881): synonym of ''Iothia emarginuloides ''Iothia emarginuloides'' is a species of sea snail, a true limpet, a marine gastropod mollusk in the family Lepetidae, one of the families of true limpets. This species was previously known as ''Iothia coppingeri''. Taxonomy The type specimens ...'' (Philippi, 1868) * ''Lepeta costulata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patella (gastropod)
''Patella'' is a genus of sea snails with gills, typical true limpets, marine gastropod mollusks in the family Patellidae, the true limpets. ''Patella'' is the type genus of the family Patellidae. Species Species within the genus ''Patella'' include: * † '' Patella alessiae'' Forli, Dell'Angelo, Montagna & Taviani, 2004 * † '' Patella alternicostata'' Sandberger, 1859 * † '' Patella ambroggii'' Lecointre, 1952 * †'' Patella amuritica'' Wilckens, 1922 * '' Patella argentaurum'' Lesson, 1831 (status in recent literature not researched by editor) * '' Patella aspera'' Röding, 1798 * '' Patella caerulea'' Linnaeus, 1758 * '' Patella candei'' d'Orbigny, 1839 * '' Patella crocata'' R.P. Lesson, 1831 * '' Patella cyanea'' R.P. Lesson, 1831 * '' Patella depressa'' Pennant, 1777 - ''Patella depressa'' is a nomen dubium according to Christiaens (1973, 1983); '' Patella intermedia'' gets priority. Nevertheless the name ''Patella depressa'' is in usage among British authors (e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerata
:''The tortrix moth genus ''Cerata'' is considered a junior synonym of ''Cydia. Cerata, singular ceras, are anatomical structures found externally in nudibranch sea slugs, especially in aeolid nudibranchs, marine opisthobranch gastropod mollusks in the clade Aeolidida. The word ceras comes from the Greek word "κέρας", meaning "horn", a reference to the shape of these structures. Cerata are dorsal and lateral outgrowths on the upper surfaces of the body of these nudibranchs. Function Cerata greatly extend the surface area of nudibranchs and aid in respiration, the process of gas exchange for metabolic use. Cerata are also used, in some cases, for attack and defense. In many aeolid nudibranchs, the digestive system extends into the cerata. These nudibranchs eat stinging celled animals (Cnidarians) such as anemones, hydroids and sea fans or Portuguese men o' war. The stinging cells or nematocysts are passed unharmed through the digestive system to cnidosacs at the tips of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nudibranch
Nudibranchs () are a group of soft-bodied marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", "dragon", or "sea rabbit". Currently, about 3,000 valid species of nudibranchs are known.Ocean Portal (2017)A Collage of Nudibranch Colors Smithsonian National Museum of Natural History. Retrieved 17 April 2018. The word "nudibranch" comes from the Latin "naked" and the Ancient Greek () "gills". Nudibranchs are often casually called sea slugs, as they are a family of opistobranchs (sea slugs), within the phylum Mollusca (molluscs), but many sea slugs belong to several taxonomic groups which are not closely related to nudibranchs. A number of these other sea slugs, such as the photosynthetic '' Sacoglossa'' and the colourful Aglajidae, are often confused with nudibranchs. Distributi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Hare
The clade Anaspidea, commonly known as sea hares ('' Aplysia'' species and related genera), are medium-sized to very large opisthobranch gastropod molluscs with a soft internal shell made of protein. These are marine gastropod molluscs in the superfamilies Aplysioidea and Akeroidea. The common name "sea hare" is a direct translation from la, lepus marinus, as the animal's existence was known in Roman times. The name derives from their rounded shape and from the two long rhinophores that project upward from their heads and that somewhat resemble the ears of a hare. Taxonomy Many older textbooks and websites refer to this suborder as "Anaspidea". The original author Paul Henri Fischer described the taxon Anaspidea at unspecified rank above family. In 1925 Johannes Thiele established the taxon Anaspidea as a suborder. 2005 taxonomy Since the taxon Anaspidea was not based on an existing genus, this name is no longer available according to the rules of the ICZN. Anaspidea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalaspidea
The order Cephalaspidea, also known as the headshield slugs and bubble snails, is a major taxon of sea slugs and bubble snails, marine gastropod mollusks within the larger clade Euopisthobranchia.Jörger K. M., Stöger I., Kano Y., Fukuda H., Knebelsberger T. & Schrödl M. (2010). "On the origin of Acochlidia and other enigmatic euthyneuran gastropods, with implications for the systematics of Heterobranchia". ''BMC Evolutionary Biology'' 10: 323. . Bubble shells is another common name for these families of marine gastropods, some of which have thin bubble-like shells. This clade contains more than 600 species. Members of this worldwide clade used to be considered the most primitive of the opisthobranchs, but now they are considered as derived and specialized members of the Euthyneura Spengel, 1881. Headshield slugs are the most morphologically diverse group of all the opisthobranchs. Anatomy The vast majority possess a shell, although it may be reduced or internal. They have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torsion (gastropod)
Torsion is a gastropod synapomorphy which occurs in all gastropods during larval development. Torsion is the rotation of the visceral mass, mantle, and shell 180˚ with respect to the head and foot of the gastropod. This rotation brings the mantle cavity and the anus to an anterior position above the head. In some groups of gastropods (Opisthobranchia) there is a degree of secondary detorsion or rotation towards the original position; this may be only partial detorsion or full detorsion. The torsion or twisting of the visceral mass of larval gastropods is not the same thing as the spiral coiling of the shell, which is also present in many shelled gastropods. Development There are two different developmental stages which cause torsion. The first stage is caused by the development of the asymmetrical velar/foot muscle which has one end attached to the left side of the shell and the other end has fibres attached to the left side of the foot and head. At a certain point in larva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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