Phylum mollusca caracteristicas pdf

Today well be looking at a wellknown, large phylum of invertebrate animals, called mollusca whose members are most often referred to as molluscs, of which around 85,000 extant species are recognised. Animales protostomos celomados, con simetria bilateral o secundariamente asimetricos y no. Mollusk, also spelled mollusc, any softbodied invertebrate of the phylum mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body. Hosted by the usgs core science analytics and synthesis. The phylum mollusca consists of over 100,000 marine, freshwater, and terrestrial species. Phylum mollusca bio 2215 oklahoma city community college dennis anderson phylum mollusca numbers of species molluscs 50,000 100,000 living species 35,000 extinct species largest pounds 80% less than 5 cm soft body most have a shell most marine snails terrestrial most habitat phylum mollusca ventral foot locomotion mantle encloses mantle cavity shell radula coelom eucoelomate. Molluscs are found in nearly all freshwater and marine. You will be amazed to know that the size of the molluscans can range from 20 metres to one millimetre, with a few microscopic animals too.

Gastropods are the most diverse class of the phylum mollusca, comprising almost three quarters of the 110,000 or so species of molluscs known. Mollusca medical definition merriamwebster medical. Synopsis of phylum mollusca molluscs identifying characteristics of phylum. To view subspecies, varieties and populations select the species. Wormlike marine surface dwellers class polyplacophora950 sp. Most gastropod shells, especially from the paleozoic, are preserved as internal. Mollusks better known as snails,clams, and other relatives all mollusks have soft bodies their name is derived from the latin word mollus meaning soft. Nov 14, 2016 zoology phylum mollusca hillary wilson. Caracteristicas generales del phylum mollusca moluscos branquia. Along with the insects and vertebrates, it is one of the most diverse groups in the animal kingdom, with nearly 100,000 possibly. Spiny skinned greek marine animals with 5 point radial pentaradial symmetry as adults. There are six classes of which three are more prominent.

Currently there are an estimated 75 thousand species, plus 35 thousand species in the fossil record. Phylum mollusca and biological diversity and evolution through time. Many organisms belonging to this phylum have a calciferous shell. Zhiqiang 2011 estima 117 358 especies descritas en una clasificacion evolutivadescriptiva. The molluscs include many familiar animals, including clams, snails, slugs, and squid, as well as some less familiar animals, like tusk shells and chitons fig. Some also serve as intermediate hosts for parasitic trematodes, and. Structure soft bodied animals name from latin word mollus meaning soft most are protected by a hard shell made of calcium carbonate have a reduced internal cell or have lost the shell completely during evolution. The latter, because it is more like the spelling of the formal name of the phylum, is easier to remember.

Many, however, occur in fresh water and some even in damp soil. Phylum mollusca has been classified differently by different authors depending upon the characters of foot, mantle, shell, muscles, radula, nervous system and respiratory organs. It includes such familiar organisms as snails, octopuses, squid, clams, scallops, oysters, and chitons. Mollusca is the secondlargest phylum of invertebrate animals after the arthropoda. Mollusca is the second largest phylum of invertebrate animals. In any case, both terms are pronounced the same way. They can be found in terrestrial regions as well as in the depths of the seas. Mollusks have a dramatic variety of form, ranging from large predatory squids and octopus, some of which show a high degree of intelligence, to grazing forms with elaborately sculpted and colored shells. In this article we will discuss about the general characters and classification of phylum mollusca. The body is divided into head, muscular foot and visceral mass.

Mollusk, any softbodied invertebrate of the phylum mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body. The number of fossil species is estimated between 60,000 and 100,000 additional species. Cuttlefish meaning of the name unique characteristics the meaning of phyllum mollusca comes from the latin word mollusk which means soft of body. Some also serve as intermediate hosts for parasitic trematodes, and others e.

Morphological hypotheses generally placed the caudofoveata and solenogastres as plesiomorphic based on their simple wormlike body plan and lack of a shell kocot et al. The proportion of undescribed species is very high. Caracteristicas generales del phylum mollusca moluscos. Wormlike marine burrowers class solenogastres250 sp. Over 50,000 of these species belong to the mostly marine and freshwater caenogastropoda while another 20,000 species belong to the subclass pulmonata, of which most are terrestrial. Itis taxonomy is based on the latest scientific consensus available, and is provided as a general reference source for interested parties. Along with the insects and vertebrates, it is one of the most diverse groups in the animal kingdom, with nearly 100,000 possibly as many as 150,000 described species. Consist of three basic parts, a foot, a visceral mass, and a mantle bilaterally symmetrical. The phylum mollusca is divided into seven distinct extant classes, three of which gastropoda, bivalvia, and cephalopoda are of major significance in terms both of species numbers and of ecological bioenergetics, and one extinct class. What are the four most common and diverse classes of molluscs. Mollusks live in marine, freshwater and terrestrial. Flattened with dorsal complete shell class gastropoda35 000 sp. Mollusca caudofoveates, solanogastres, chitons, monoplacophorans, scaphopods, bivalves, gastropods, cephalopods common name.

While every effort has been made to provide the most reliable and uptodate information available, ultimate legal requirements with respect to species are contained in. Brusca and others published phylum mollusca find, read and cite all the research you need on researchgate. Mollusks are the second largest phylum in the animal kingdom after the phylum arthropoda. Mollusks are the largest marine phylum, comprising about 23% of all the named marine organisms. They possess osphradia to test the chemical nature of water. The word mollusc comes from the latin word mollis, which means soft. However, it is not a legal authority for statutory or regulatory purposes.

The bodies are generally very soft and are covered by the hard exoskeleton. Hours to centuriesthe oldest is known to have lived over 500 years diet. Mollusca is one of the most diverse groups of animals on the planet, with at least 50,000 living species and more likely around 200,000. The body of molluscs is unsegmented with a distinct head, muscular foot and visceral hump. Other than worm like classes, all descended from ham. Jun 11, 2017 the body is divided into head, muscular foot and visceral mass. Ruppert and barnes 1994, meglitsch and schram 1991 divided molusca into 7 classes, while parker and haswell 1972, morton and yonge 1964 have clubbed class. The phylum mollusca is the secondlargest animal phylum, with over 100,000 species. Around 85,000 extant species of molluscs are recognized. Flattened with dorsal segmented shell class monoplacophora25 sp. Introductionmollusca is the latinfor softincludes snails, squids,nautilus, octopus,clams, etc. Phylum mollusca bio 2215 oklahoma city community college dennis anderson phylum mollusca numbers of species molluscs 50,000 100,000 living species 35,000 extinct species largest pounds 80% less than 5 cm soft body most have a shell most marine snails terrestrial most habitat phylum mollusca ventral foot locomotion mantle encloses mantle cavity shell radula coelom. Some people use the term mollusk for a member of phylum mollusca, whereas others use the term mollusc.