The animals belonging to the phylum mollusca have softbodies, triploblastic and bilaterally symmetrical. Phylum mollusca is a very diverse 85,000 species group of mostly marine species. Covers details of the phylum mollusca learn with flashcards, games, and more for free. External fertilization occurs when there are two separate sexes and a. A free powerpoint ppt presentation displayed as a flash slide show on id. Either the giant squid or the colossal squid is the largest known invertebrate.
Organized into 11 chapters, this volume begins with an overview of the phylum mollusca. Both classes consist of free living and parasitic roundworms that live in. The structure and classification of the arthropoda. They are sluggish invertebrates, with a thin fleshy envelope known a the mantle. List of animal phyla simple english wikipedia, the free. This book has informations about phylum mollusca which has great potential in aquatic resources. Media in category mollusca the following 200 files are in this category, out of 972 total. A list of this type may be arranged alphabetically. It will also be used to setup a comparison between the major classes gastropoda, bivalvia, cephalopoda, and polyplacophora and to introduce. Phylum mollusca characteristics, classification and examples. The phylum mollusca consists of over 100,000 marine, freshwater, and terrestrial. Phylum mollusca it is estimated that 23 percent of all known marine species are mollusks.
List of animal phyla is a list of the major groups of animals usually classified as a phylum. Synopsis of phylum mollusca molluscs identifying characteristics of phylum. Most are marine, but many are freshwater and some live on the land. This text then provides information about the general features of the main classes and their evolution, the anatomical organization of mollusks, and a classification of the primary taxonomic groups of mollusks. Phylum mollusca reproduction most mollusks are dioecious, with external fertilization most mollusks have a larval stage depending on species, fertilization may. Molluscs are soft bodied animals, often with hard shells for protection. Molluscs are found in nearly all freshwater and marine.
Williams and others published phylum mollusca, class bivalvia. They can be found in terrestrial regions as well as in the depths of the seas. Phylum mollusca article about phylum mollusca by the free. Many organisms belonging to this phylum have a calciferous shell. Phylum mollusca mollis, soft over 90,000 living species 70,000 fossil species some are herbivorous grazers some are predaceous carnivores many are filter feeders some are parasites mostly marine but some terrestrial and freshwater. This then is the plan of a basic unevolved mollusc. Body does not have 8 dorsal shell plates, may or may not be flattened. Some also serve as intermediate hosts for parasitic trematodes, and others e. The phylum is usually divided into 9 or 10 taxonomic classes, of which two are entirely extinct. 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. The bodies are generally very soft and are covered by the hard exoskeleton. Its fun if you can understand the need for it and how its done. To value these shall animals their classification anatomy and physiological aspects of various classgenus are described with important biological systems like digestive, respiratory, circulatory, excretory, sense organs and reproductive etc. Freshwater molluscs are classified into gastropods snails and freshwater limpets and several groups of.
Classification can be great fun and not as utterly boring as it sometimes turns out to be. Despite the diversity of form and function among the molluscs, all members of this group have the same basic body plan. Classification of phylum mollusca biology libretexts. These warm ups cover the characteristics of each phylum, the classes of each phylum, the mollusk and annelid body plan, the clam, the earthworm, and more. Two of these are class enoplea and class chromadorea, each having at least one subclass. Hopefully i will get something written about each class in the not too distant future. Species in the mollusca phylum reproduce either through external or internal fertilization. Phylum annelida contains earthworms and wormlike creatures that have segmented bodies.
Phylum mollusca is a very diverse 85,000 species group of mostly marine species, with a dramatic variety of form. Classification of mollusca april, 97 1 victor millard a classification of the living mollusca which was compiled by kay cunningham vaught and published by american malacologists, inc melbourne, florida 32902, usa in 1989 was used as the basis for this compilation. They are selective predators of microinvertebrates living within the sediment. The phylum mollusca is the secondlargest animal phylum, with over 100,000 species. 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. Mollusc simple english wikipedia, the free encyclopedia. Zoology mollusks block 1 nabinger purpose this lesson is intended to introduce the phylum mollusca and to go over its general physical characteristics.
The phylum mollusca consists of over 100,000 marine, freshwater, and terrestrial species. Includes animals such as squids, snails, oysters, clams and slugs. 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. They use the phylum mollusca to undersand three major macroevolutionary patterns. Class polyplacophora better known as chitons or coatofmail shells, these. Ppt phylum mollusca powerpoint presentation free to. Scavengers along beach and coast lines, their body is in a hol. Differentiate among the classes in the phylum mollusca. Flattened body has 8 dorsal shell plates, usually visible dorsally.
The rotifera are characterised by the retention of what appears in molluscs and chaatopods as an embryonic organ, the velum or ciliated prasoral girdle, as a locomotor and foodseizing apparatus, and by the reduction of the muscular. It is estimated that 23 percent of all known marine species are mollusks. Phylum mollusca mollis, soft over 90,000 living species 70,000 fossil species. 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. Mantle and cavity mantle is a sheath of skin on side of body. Mnemonic classes and subclasses of phylum mollusca in. Internal fertilization occurs when the species functions as both sexes and is thus a hermaphrodite.
Mollusc a lab dissection of a representative of class bivalvia. Differentiate among the classes in the phylum mollusca key points mollusks can be segregated into seven classes. This basic plan is changed and adapted, for the requirements of different lifestyles, almost beyond recognition in some of the 6 classes of mollusca. Cephalopod molluscs, such as squid, cuttlefish and octopus, are among the most neurologically advanced of all invertebrates. Characteristic features of phylum mollusca they are bilaterally symmetrical. The original form was bilaterally symmetrical, and this symmetry is retained in all the classes except the gastropoda. Some grownups cant see magic ponies but children can explanation. 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. Chitons or sea cradles elongated, dorsoventrally flattened marine, on rocky intertidal substrates head reduced in size shell consists of 8 dorsal plates chitons are common inhabitants of hard. Gastropods are the most diverse class of the phylum mollusca, comprising almost three quarters of the 110,000 or so species of molluscs known. A study of the type series of nautilus pompilius linnaeus, 1758 mollusca, cephalopoda, nautilida svetlana v. Mnemonic classes and subclasses of phylum mollusca in taxonomy. The references in that work have not been transferred to this one. The term mollusca was first given by aristotle to cuttlefish.
Mollusca 251 class scaphopoda the appropriately named tusk shells are a distinctive group of molluscs found in association with soft and unconsolidated substrata into which they burrow. Class aplacophora forms no hard parts and has no fossil. Brusca and others published phylum mollusca find, read and cite all the research you need on researchgate. The characteristic organs of mollusca are the mantle and shell, the foot, the ctenidia and the radula, of which all but the last are external. Aplacophora, monoplacophora, polyplacophora, bivalvia, gastropoda, cephalopoda, and scaphopoda. Introduction to mollusca and the class gastropoda chapter pdf available. Mollusca is the secondlargest phylum of invertebrate animals after the arthropoda. Mollusca is a phylum of species that range from the cuttlefish to the sea snail. Origin, phylogeny and classification of the phylum mollusca. Around 85,000 extant species of molluscs are recognized. Phyla mollusca and annelida no prep warm ups, bell ringers, or inserts for interactive notebooks.
662 1194 71 690 120 27 1038 307 148 1100 416 606 872 1002 1052 959 1043 1500 1537 867 365 1392 454 1123 605 896 836 637 629 604 933 1031 166 106 1324 1338 1223 202