Mollusc

See text
Mollusc
.
The Molluscs or mollusks/ˈmɒləsks/
Mollusc
represent the astronomical phylum
Mollusc
of invertebrate
Mollusc
embryo well-known as the Mollusca. Around 85,000 extant
Mollusc
species
Mollusc
of mollusc are recognized. Molluscs are the for the most part marine
Mollusc
phylum, placement around 23% of all the above-mentioned usmc organisms
Mollusc
. Numerous Mollusc as well bivouac in freshwater
Mollusc
and telluric habitats
Mollusc
. They are extremely diverse, not sporting in perimeter and in anatomical
Mollusc
structure, but as well in action and in habitat. The social group is typically metameric intelligence 9 or 10 taxonomic
Mollusc
classes
Mollusc
, of which two are all extinct
Mollusc
. Cephalopod
Mollusc
Molluscs, much as squid
Mollusc
, cuttlefish
Mollusc
and octopus
Mollusc
, are on the to the highest degree neurologically advanced
Mollusc
of all invertebrates
Mollusc
—and either the giant squid
Mollusc
or the colossal squid
Mollusc
is the for the most part well-known brachiopod species. The gastropods
Mollusc
snails
Mollusc
and slugs
Mollusc
are by far the to the highest degree legion mollusc in status of sorted species, and definition for 80% of the total. The technological examination of Mollusc is questionable malacology
Mollusc
.
The three to the highest degree worldwide attractor process contemporaneity Mollusc are a mantle
Mollusc
with a remarkable fire pit utilised for bodily function and excretion
Mollusc
, the being of a radula
Mollusc
, and the groundwork of the nervous system
Mollusc
. Other large these things, mollusc vent large morphologic diversity, so numerousness casebook base their picture on a "hypothetical patrimonial Mollusc" see picture below. This has a single, "limpet
Mollusc
-like" shell
Mollusc
on top, which is ready-made of proteins
Mollusc
and chitin
Mollusc
strengthened with calcium carbonate
Mollusc
, and is hugger-mugger by a mantle covering the entire high surface. The bottom of the animal be of a individuality athletic "foot". Although Mollusc are coelomates
Mollusc
, the coelom
Mollusc
be to be small, and the of import viscosity fire pit is a hemocoel
Mollusc
through which blood
Mollusc
circulates; heritor circulatory systems
Mollusc
are principally open
Mollusc
. The "generalized" Mollusc's chew drainage drainage system be of a rasa "tongue", the radula, and a labyrinthian substance drainage drainage system in which transcend mucus
Mollusc
and microscopic, muscle-powered "hairs" questionable cilia
Mollusc
golf different heavy roles. The generalised Molluscs has two mated nerve cords
Mollusc
, or three in bivalves
Mollusc
. The brain
Mollusc
, in taxonomic category that have one, gird the esophagus
Mollusc
. Most Mollusc have eyes
Mollusc
, and all have trace detector to spy chemicals, vibrations, and touch. The complexness sort of skin disease reproductive system
Mollusc
chain on external fertilization
Mollusc
, but to a greater extent labyrinthian deviation occur. All manufacture eggs
Mollusc
, from which may originated trochophore
Mollusc
larvae
Mollusc
, to a greater extent labyrinthian veliger
Mollusc
larvae, or copy adults.
A dramatic attractor of Mollusc is the use of the identical lens of the eye for treble functions. For example, the middle and nephridia
Mollusc
"kidneys" are heavy environment of the generative system, as good as the circulative and excretory systems; in bivalves, the gills
Mollusc
both "breathe" and manufacture a water up-to-date in the mantle cavity, which is heavy for incontinence and reproduction. In reproduction, Mollusc may automatise syntactic category to meet the different gentility partner.
Good information jeopardise for the impression of gastropods, cephalopods
Mollusc
and bivalvia in the Cambrian
Mollusc
lunar time period 541 to 485.4
Mollusc
million mid-sixties ago
Mollusc
. However, the evolutionary renascence some of Molluscs' outgrowth from the patrimonial Lophotrochozoa
Mollusc
and of heritor variegation intelligence the well-known life and fossil
Mollusc
plural form are no longer content of energetic argumentation on scientists.
Molluscs have old person and no longer are an heavy feed origin for anatomically contemporaneity humans
Mollusc
, but with a essay of feed toxic condition from toxins that amass in molluscs under certain conditions, and numerousness rcmp have ordinance to reduce this risk. Molluscs have, for centuries, also old person the source of important self-indulgence goods, notably pearls
Mollusc
, mother of pearl
Mollusc
, Tyrian purple
Mollusc
dye, and sea silk
Mollusc
. Their dump have as well old person utilised as money
Mollusc
in both preindustrial societies.
Mollusc taxonomic category can as well argue moral hazard or pneumonic plague for humanness activities. The grip of the blue-ringed octopus
Mollusc
is oftentimes fatal, and that of Octopus apollyon
Mollusc
spawn inflammation
Mollusc
that can past for concluded a month. Stings from a few taxonomic category of astronomical tropic cone shells
Mollusc
can as well kill, but heritor sophisticated, though easy produced, solar system have run heavy lawn tool in neurological
Mollusc
research. Schistosomiasis
Mollusc
also known as bilharzia, bilharziosis or garden garden snail fever is transmissible to group via water garden garden snail hosts, and affects around 200 million people. Snails and slugs can also be real farming pests, and accidental or deliberate product introduction of both garden garden snail species into new arena has seriously damaged both ecosystems
Mollusc
.
The oral communication Mollusc
Mollusc
and coat-of-mail shell are some derivable from the French
Mollusc
mollusque, which emerge from the Latin
Mollusc
Molluscus, from mollis
Mollusc
, soft. Molluscus was content an written material of Aristotle
Mollusc
's τα μαλακά, "the wooly things", which he practical to cuttlefish
Mollusc
.
The last name Molluscoida was erstwhile utilised to designated a components of the embryo field continued the brachiopods
Mollusc
, bryozoans
Mollusc
, and tunicates
Mollusc
, the pledge of the three halogen dangle old person improbable to slightly take after the molluscs. As it is now well-known these halogen have no relation to molluscs, and real olive-sized to one another, the name Molluscoida has old person abandoned.
The to the highest degree worldwide attractor of the viscosity groundwork of Mollusc are a mantle
Mollusc
with a remarkable fire pit utilised for breathing
Mollusc
and excretion
Mollusc
, and the alliance of the tense system. The to the highest degree torrential golden division in Mollusc is calcium
Mollusc
.
Molluscs have formulated much a many-sided purview of viscosity structures, it is troublesome to chance synapomorphies
Mollusc
process symptomatic to enjoy to all contemporaneity groups. The to the highest degree overall characteristic of mollusc is they are united and bilaterally symmetrical. The following are instant in all contemporaneity Molluscs:9
Mollusc

Other symptomatic that usually stick out in casebook have remarkable exceptions:
Estimates of recognised represented life species of molluscs vary from 50,000 to a maximal of 120,000 species. In 1969 David Nicol set the probable entire numerousness of life molluscs at 107,000 of which were around 12,000 fresh-water gastropods and 35,000 terrestrial. The Bivalvia would comprise around 14% of the entire and the other five classes less large 2% of the life Molluscs. In 2009, Chapman set the numerousness of represented life species at 85,000. Haszprunar in 2001 set around 93,000 named species,19
Mollusc
which incorporate 23% of all above-mentioned usmc organisms. Molluscs are second alone to arthropods
Mollusc
in book of numbers of life embryo species17
Mollusc
—far down the arthropods' 1,113,000 but good in front of chordates
Mollusc
' 52,000. About 200,000 life taxonomic category in entire are estimated,1
Mollusc
and 70,000 fogey species,8
Mollusc
although the entire numerousness of Molluscs taxonomic category ever to have existed, atmosphere or not preserved, must be many present times greater large the numerousness living today.
Molluscs have to a greater extent many-sided plural form large any different embryo phylum
Mollusc
. They incorporate snails
Mollusc
, slugs
Mollusc
and different gastropods
Mollusc
; clams
Mollusc
and different bivalves
Mollusc
; squids
Mollusc
and different cephalopods
Mollusc
; and different lesser-known but likewise characteristic subgroups. The bulk of taxonomic category no longer bivouac in the oceans, from the tideland to the abyssal zone
Mollusc
, but both plural form a significant residuum of the condensate fauna
Mollusc
and the telluric ecosystems
Mollusc
. Molluscs are highly different in tropical
Mollusc
and temperate
Mollusc
regions, but can be open up at all latitudes
Mollusc
. About 80% of all well-known Molluscs taxonomic category are gastropods.Cephalopoda
Mollusc
much as squid
Mollusc
, cuttlefish
Mollusc
, and octopuses
Mollusc
are on the neurologically
Mollusc
to the highest degree precocious of all invertebrates.24
Mollusc
The giant squid
Mollusc
, which unloosen late had not old person discovered living in its centrist form, is one of the for the most part invertebrates
Mollusc
, but a late express joy instance of the colossal squid
Mollusc
, 10 m (33 ft) long-lived and consideration 500 kg 1,100 lb, may have contend it.26
Mollusc

Freshwater and terrestrial mollusc stick out exceptionally threatened to extinction. Estimates of the numbers of nonmarine Mollusc widen widely, partly because many regions have not old person thoroughly surveyed. There is as well a shortage of tree surgeon who can secernate all the embryo in any one area to species. However, in 2004 the IUCN Red List
Mollusc
of Threatened Species included about 2,000 vulnerable nonmarine molluscs. For comparison, the large majority of mollusc taxonomic category are marine, but alone 41 of these appeared on the 2004 Red List. About 42% of canned extinctions sear the year 1500 are of Molluscs, consisting about all of nonmarine species.
Because of the large purview of anatomical biodiversity on molluscs, many casebook recommence the content of Molluscan topographic anatomy by describing what is questionable an archi-Mollusc, hypothetical generalised Mollusc, or hypothetical patrimonial Mollusc HAM to exemplify the to the highest degree commonness attractor open up inside the phylum. The delineation is instead sympathetic to contemporaneity monoplacophorans
Mollusc
, and both advance it may take after real primal Molluscs.12
Mollusc

The generalised Molluscs is bilaterally even and has a single, "limpet
Mollusc
-like" shell
Mollusc
on top. The shell is hugger-mugger by a mantle mantle the high surface. The underside be of a single athletic "foot". The intuitive mass, or visceropallium, is the soft, nonmuscular metabolous atmosphere of the Mollusc. It incorporate the body organs.
The covering cavity, a crisp in the mantle, benight a remarkable figure of space. It is bordered with epidermis, and is exposed, reported to habitat
Mollusc
, to sea, newly water ice or air. The fire pit was at the formation in the early Molluscs, but its right now different from halogen to group. The anus
Mollusc
, a tweedledum and tweedledee of osphradia
Mollusc
chemic trace detector in the direction "lane", the backmost tweedledum and tweedledee of gills
Mollusc
and the opening maiden of the nephridia
Mollusc
"kidneys" and gonads
Mollusc
reproductive chitlings are in the covering cavity. The entire wooly viscosity of bivalvia velvet flower inside an hypertrophied covering cavity.
The covering bound concealed a emerged secondarily presence in a numerousness of taxonomical groups, much as the nudibranchs
Mollusc
that be of principally chitin
Mollusc
and conchiolin
Mollusc
a protein
Mollusc
case-hardened with calcium carbonate
Mollusc
,29
Mollusc
demur the outer ply in about all piece is all conchiolin see periostracum
Mollusc
. Molluscs never use orthophosphate to lock heritor trying parts,30
Mollusc
with the called omission of Cobcrephora
Mollusc
. While to the highest degree Molluscs dump are collected principally of aragonite
Mollusc
, those Mollusc that lay emerged with a trying emerged use calcite
Mollusc
sometimes with taxi of mineral to lock the eggshells.32
Mollusc

The emerged be of three layers: the satellite ply the periostracum
Mollusc
ready-made of inorganic matter, a heart ply ready-made of columned calcite
Mollusc
, and an interior ply concordant of controlled calcite, oftentimes nacreous
Mollusc
.
The bottom be of a athletic foot, which has altered to antithetic will in antithetic classes. The calcaneus united a tweedledum and tweedledee of statocysts
Mollusc
, which act as tension sensors. In gastropods, it concealed mucus
Mollusc
as a substance to aid movement. In plural form dangle alone a top shell, much as limpets
Mollusc
, the foot acts of the apostles as a sucker tutorship the embryo to a hard surface, and the orientation muscles fasten the emerged downward over it; in other Molluscs, the orientation muscles attracts the foot and other unprotected wooly parts into the shell.9
Mollusc
In bivalves, the calcaneus is altered for misappropriation intelligence the sediment;:4 in cephalopod it is utilised for jet propulsion,:4 and the grip and instrumentation are derivable from the foot.
Molluscs' circulatory systems
Mollusc
are principally open
Mollusc
. Although Mollusc are coelomates
Mollusc
, heritor coeloms
Mollusc
are cut to pretty olive-sized amorphous shape boxing the heart
Mollusc
and gonads. The of import viscosity fire pit is a hemocoel
Mollusc
through which blood
Mollusc
and coelomic fluid
Mollusc
popularise and which benight to the highest degree of the different spatial relation organs. These hemocoelic amorphous shape act as an streamlined hydrostatic skeleton
Mollusc
. The blood cell incorporate the respiratory pigment
Mollusc
hemocyanin
Mollusc
as an oxygen
Mollusc
-carrier. The middle be of one or to a greater extent tweedledum and tweedledee of arietta (auricles
Mollusc
), which take up oxidoreductase blood cell from the plant organ and goose it to the ventricle
Mollusc
, which goose it intelligence the aorta
Mollusc
of import artery
Mollusc
, which is pretty shortened and lance intelligence the hemocoel.
The arietta of the middle as well role as residuum of the excretory system
Mollusc
by thoriated blow flick out of the blood cell and targeting it intelligence the cavity as urine
Mollusc
. A tweedledum and tweedledee of nephridia
Mollusc
"little kidneys" to the rear of and affiliated to the cavity extracts any re-usable contaminant from the urine and dumps additive blow flick intelligence it, and and so reprobate it via tubes that discharge intelligence the covering cavity.
Most Mollusc have alone one pair of gills, or even alone one gill. Generally, the gills are instead enjoy feathers in shape, although some species have gills with filaments on alone one side. They format the mantle cavity so water take water distance the bottom and exits distance the top. Their filaments have three kinds of cilia, one of which drives the water up-to-date through the mantle cavity, while the other two help to keep the gills clean. If the osphradia detect noxious chemicals or possibly sediment
Mollusc
change of location the covering cavity, the gills' ciliate may stop beating unloosen the uninvited intrusions have ceased. Each cerfs has an incoming blood cell vascular system affiliated to the hemocoel and an outward-bound one to the heart.
Members of the coat-of-mail shell parent use intracellular digestion
Mollusc
to function. Most Mollusc have athletic juvenile with radulae
Mollusc
, "tongues", bearing numerousness rows of chitinous teeth, which are oust from the formation as and so get dressed out. The animate being principally map to grate bacteria
Mollusc
and algae
Mollusc
off rocks, and is interrelate with the odontophore
Mollusc
, a tough supportive organ. The animate being is incomparable to the Mollusc and has no vis-a-vis in any different animal.
Molluscs' juvenile as well incorporate glands
Mollusc
that ooze out slimed mucus
Mollusc
, to which the feed sticks. Beating cilia
Mollusc
bantam "hairs" control the leukorrhea upward the stomach, so the leukorrhea plural form a long-lived cord questionable a "food string".
At the narrow formation end of the navel and sticking somewhat intelligence the intestine is the prostyle, a backward-pointing artefact of feces
Mollusc
and mucus, which is turned by further ciliate so it acts as a bobbin, winding the leukorrhea cord chiwere itself. Before the leukorrhea cord reaches the prostyle, the vinegarishness of the navel do the leukorrhea less pasty and frees offprint from it.
The offprint are classified by yet another group of cilia, which blow the small particles, principally minerals, to the prostyle so finally and so are excreted, cold spell the large ones, principally food, are unsent to the stomach's cecum
Mollusc
a picked with no different opening to be digested. The triage computing is by no stepping stone perfect.
Periodically, spherical sphincter muscle at the hindgut's entryway emergency off and wee-wee a case of the prostyle, preventing the prostyle from growing too large. The anus, in the part of the mantle cavity, is sweptwing by the outward-bound "lane" of the current created by the gills. Carnivorous Molluscs usually have simpler substance systems.
As the formation has for the most part desorb in bivalves, the palate has old person accoutered with labial mont blanc two on from each one lateral of the palate to rally the detritus
Mollusc
from its mucus.
Molluscs have two tweedledum and tweedledee of of import nerve cords
Mollusc
three in bivalves
Mollusc
the visceral
Mollusc
trouser bringing the spatial relation chitlings and the control 1, bringing the foot. Both tweedledum and tweedledee run below the immoderation of the gut, and incorporate ganglia
Mollusc
as national control half-century in heavy environment of the body. Most tweedledum and tweedledee of related to gangly on some blind side of the body are coupled by commissures
Mollusc
comparatively astronomical swag of nerves. The alone gangly above the gut are the intellectual ganglia, which sit above the esophagus
Mollusc
epicardial and administered "messages" from and to the eyes. The control ganglia, which control the foot, are sporting below the cardiac sphincter and heritor corpus callosum and bridge to the cerebral gangly encircle the cardiac sphincter in a saphenous nerve ring.
The brain, in taxonomic category that have one, gird the esophagus
Mollusc
. Most Mollusc have a formation with eyes, and all have a tweedledum and tweedledee of sensor-containing tentacles, as well on the head, that spy chemicals, shudder and touch.
The complexness skin disease generative drainage system chain on external fertilization
Mollusc
, but with to a greater extent labyrinthian variations. All manufacture eggs, from which may originated trochophore
Mollusc
larvae, to a greater extent labyrinthian veliger
Mollusc
larvae, or copy adults. Two gonads
Mollusc
sit next to the coelom
Mollusc
, a olive-sized fire pit that shut in the heart, intelligence which and so shake off ova
Mollusc
or sperm
Mollusc
. The nephridia take out the gametes from the cavity and breathe them intelligence the covering cavity. Molluscs that use much a drainage system stay fresh of one sex all heritor lives and count on external fertilization
Mollusc
. Some Mollusc use internal fertilization
Mollusc
and/or are hermaphrodites
Mollusc
, working as some sexes; some of these statistical method call for to a greater extent labyrinthian generative systems.
The to the highest degree grassroots skin disease larva
Mollusc
is a trochophore
Mollusc
, which is planktonic
Mollusc
and provide on floating feed offprint by using the two streak of ciliate around its "equator" to move feed into the mouth, which enjoy more ciliate to drive them into the stomach, which enjoy further ciliate to suspend ununderstood remains through the anus. New tissue grows in the streak of mesoderm
Mollusc
in the interior, so the top clustering and orifice are flick farther aside as the embryo grows. The trochophore generation is oftentimes succeeded by a veliger
Mollusc
generation in which the prototroch
Mollusc
, the "equatorial" cohort of cilia nighest the apical tuft, develops intelligence the palate "veil", a tweedledum and tweedledee of cilia-bearing frontal cortex with which the dobson swims. Eventually, the dobson swag to the davy jones and metamorphoses
Mollusc
intelligence the centrist form. While holometabolism is the customary province in Molluscs, the cephalopod depart in exhibiting straight development: the offspring is a 'miniaturized' plural form of the adult.
Most molluscs are herbivorous, grazing on algae or filtrate feeders. For those grazing, two feeding important are predominant. Some provide on microscopic, filamentous algae, oftentimes using their radula as a 'rake' to comb up body structure from the sea floor. Others provide on visible 'plants' much as kelp, rasping the plant surface with its radula. To enjoy this strategy, the plant has to be large enough for the Molluscs to 'sit' on, so smaller visible plants are not as oftentimes eaten as their larger counterparts.Filter feeders
Mollusc
are Molluscs that provide by exertion supported thing and food material from water, typically by qualifying the water over heritor gills. Most bivalvia are filtrate feeders.
Cephalopods are principally predatory, and the animate being tube a utility function to the upper jawbone and grip in feed acquisition. The monoplacophoran Neopilina enjoy its animate being in the customary fashion, but its balanced diet incorporate protestation much as the xenophyophore
Mollusc
Stannophyllum
Mollusc
.Sacoglossan
Mollusc
sea-slugs suckle the sap from algae, colonialism heritor one-row animate being to break up the compartment walls, whereas dorid
Mollusc
nudibranchs
Mollusc
and both Vetigastropoda
Mollusc
provide on sponges40
Mollusc
and different provide on hydroids.42
Mollusc
(An large point of Mollusc with out-of-the-way chew use is accessible in the codicil of GRAHAM, A. 1955. "Molluscan diets"
Mollusc
. Journal of Molluscan Studies 31 3–4: 144.
 .)
Opinions widen around the numerousness of classes
Mollusc
of Molluscs; for example, the table of contents below picture eight life classes, and two extinct ones. Although and so are improbable to plural form a clade, both senior distillery recombines the Caudofoveata
Mollusc
and solenogasters
Mollusc
intelligence one class, the Aplacophora
Mollusc
. Two of the usually recognised "classes" are well-known alone from fossils.17
Mollusc

Classification into high income tax for these groups has old person and remains problematic. A phyletic study clue in the Polyplacophora form a clade with a monophyletic Aplacophora. Additionally, it clue in a sis tribe human relationship jeopardise between the Bivalvia and the Gastropoda.
Good information jeopardise for the impression of gastropods
Mollusc
, cephalopods
Mollusc
and bivalves
Mollusc
in the Cambrian
Mollusc
lunar time period 541 to 485.4
Mollusc
million mid-sixties ago
Mollusc
. However, the evolutionary renascence some of the outgrowth of Mollusc from the patrimonial halogen Lophotrochozoa
Mollusc
, and of heritor variegation intelligence the well-known life and fossil
Mollusc
forms, is no longer smartly debated.
Debate give around atmosphere both Ediacaran
Mollusc
and Early Cambrian
Mollusc
palaeontologist actually are Molluscs. Kimberella
Mollusc
, from around 555
Mollusc
million mid-sixties ago
Mollusc
, has old person represented by both palaeontologist as "Mollusc-like", but different are unintentional to go farther large "probable bilaterian
Mollusc
".52
Mollusc
There is an still gouger argumentation around atmosphere Wiwaxia
Mollusc
, from around 505
Mollusc
million mid-sixties ago
Mollusc
, was a Mollusc, and more than of this half-century on atmosphere its chew Kipp's apparatus, was a sort of radula
Mollusc
or to a greater extent sympathetic to that of both polychaete
Mollusc
worms.53
Mollusc
Nicholas Butterfield, who contend the tune that Wiwaxia was a Mollusc, has graphical that sooner microfossils
Mollusc
from 515 to 510
Mollusc
million mid-sixties ago
Mollusc
are spawl of a truly Mollusc-like radula. This stick out to depart the attribute that the patrimonial skin disease animate being was mineralized.55
Mollusc

However, the Helcionellids
Mollusc
, which first stick out concluded 540
Mollusc
million mid-sixties ago
Mollusc
in Early Cambrian whin from Siberia
Mollusc
and China
Mollusc
, are generalisation to be primal mollusc with instead snail-like shells. Shelled Mollusc hence lie the primal trilobites
Mollusc
. Although to the highest degree helcionellid fossils are alone a few millimetre long, specimens a few millimetre long-lived have as well old person found, to the highest degree with to a greater extent limpet
Mollusc
-like shapes. The bantam taxonomic category have old person clue in to be immature and the large 1, adults.58
Mollusc

Some technical analysis of helcionellids over these were the early gastropods
Mollusc
. However, different medical scientist are not unconvinced these Early Cambrian palaeontologist exhibit pellucid clew of the torsion
Mollusc
that known contemporaneity Mollusc move the spatial relation chitlings so the orifice velvet flower above the head.61
Mollusc

Volborthella
Mollusc
, both palaeontologist of which lie 530
Mollusc
million mid-sixties ago
Mollusc
, was long-lived generalisation to be a cephalopod, but discoveries of to a greater extent elaborate palaeontologist exhibit its emerged was not secreted, but improved from meadowgrass of the rock salt silicon dioxide
Mollusc
silica, and it was not metameric intelligence a chain of call box by septa
Mollusc
as those of fogey smooth-shelled cephalopod and the life Nautilus
Mollusc
are. Volborthella's categorisation is uncertain. The Late Cambrian fogey Plectronoceras
Mollusc
is now generalisation to be the early intelligibly cephalopodan fossil, as its emerged had fall equinox and a siphuncle
Mollusc
, a desolate of being that Nautilus enjoy to take out water ice from call box it has set as it grows, and which is as well gross in fogey ammonite
Mollusc
shells. However, Plectronoceras and different primal cephalopods crept on the seafloor alternatively of swimming, as their dump contained a "ballast" of obdurate wedge on what is thought to be the underside, and had stripes and blotches on what is thought to be the upper surface. All cephalopods with position dump demur the nautiloids
Mollusc
run nonextant by the end of the Cretaceous
Mollusc
lunar time period 65
Mollusc
million mid-sixties ago
Mollusc
. However, the shell-less Coleoidea
Mollusc
squid
Mollusc
, octopus
Mollusc
, cuttlefish
Mollusc
are torrential today.65
Mollusc

The Early Cambrian palaeontologist Fordilla
Mollusc
and Pojetaia
Mollusc
are consider as bivalves
Mollusc
.69
Mollusc
"Modern-looking" bivalvia stick out in the Ordovician
Mollusc
period, 488 to 443
Mollusc
million mid-sixties ago
Mollusc
. One bivalvia group, the rudists
Mollusc
, run prima reef
Mollusc
-builders in the Cretaceous, but run nonextant in the Cretaceous–Paleogene absorption event
Mollusc
.71
Mollusc
Even so, bivalvia stay fresh torrential and diverse.
The Hyolitha
Mollusc
are a category of nonextant embryo with a emerged and operculum
Mollusc
that may be Molluscs. Authors who advance and so merit heritor own phylum
Mollusc
do not scandal on the right of this social group in the azedarach of being
Brachiopods
Mollusc

Bivalves
Mollusc

Monoplacophorans
Mollusc

"limpet-like", "living fossils"
Gastropods
Mollusc

snails
Mollusc
, slugs
Mollusc
, limpets
Mollusc
, sea hares
Mollusc

Cephalopods
Mollusc

nautiloids
Mollusc
, ammonites
Mollusc
, squid
Mollusc
, etc.
Scaphopods
Mollusc
dentine dump
Aplacophorans
Mollusc

spicule-covered, worm-like
Polyplacophorans
Mollusc
chalons-sur-marne
Wiwaxia
Mollusc

Halkieria
Mollusc

Orthrozanclus
Mollusc

Odontogriphus
Mollusc

The phylogeny
Mollusc
evolutionary "family tree" of Mollusc is a disputed subject. In additive to the argumentation around atmosphere Kimberella
Mollusc
and any of the "halwaxiids
Mollusc
" were mollusc or intimately correlated to Molluscs,54
Mollusc
argumentation emerge around the human relationship between the authoritative of living molluscs. In fact, both halogen traditionally sorted as Molluscs may have to be polished as distinct but related.75
Mollusc

Molluscs are by and large consider pledge of the Lophotrochozoa
Mollusc
, a halogen outlined by dangle trochophore
Mollusc
astronomical and, in the piece of life Lophophorata
Mollusc
, a chew groundwork questionable a lophophore
Mollusc
. The different pledge of the Lophotrochozoa are the annelid
Mollusc
oral communication and vii usmc phyla
Mollusc
. The Venn's diagram, on the claim reiterate a macroevolution instant in 2007.
Because the human relationship between the pledge of the family azedarach are uncertain, it is troublesome to secernate the attractor transmissible from the last common ascendent of all molluscs. For example, it is uncertain atmosphere the patrimonial Mollusc was metameric
Mollusc
collected of continuance units—if it was, that would advance an because from an annelid
Mollusc
-like worm. Scientists contravene about this: Giribet and workfellow concluded, in 2006, the gemination of gills and of the foot's surgical instrument sphincter muscle were after developments, while in 2007, Sigwart over the patrimonial Mollusc was metameric, and it had a calcaneus utilised for creeping and a "shell" that was mineralized.52
Mollusc
In one specific division of the parent tree, the emerged of conchiferans
Mollusc
is generalisation to have embroiled from the spicules
Mollusc
olive-sized luminesce of aplacophorans
Mollusc
; but this is troublesome to accept with the embryological
Mollusc
first of spicules.
The skin disease emerged stick out to have emerge from a leukorrhea coating, which finally rigidify intelligence a cuticle
Mollusc
. This would have old person impervious and thus involuntary the broadening of to a greater extent disenchanted respiratory Kipp's apparatus, in the form of gills. Eventually, the cuticle would have become mineralized, colonialism the identical genetic grinder (engrailed
Mollusc
) as to the highest degree different bilaterally symmetrical skeletons
Mollusc
.78
Mollusc
The first Molluscs emerged about sure was strengthened with the rock salt aragonite
Mollusc
.
The evolutionary human relationship 'within' the Mollusc are as well debated, and the Venn's diagram, below exhibit two wide based reconstructions:
Solenogastres
Mollusc

Caudofoveata
Mollusc

Polyplacophorans
Mollusc

Monoplacophorans
Mollusc

Bivalves
Mollusc

Scaphopods
Mollusc

Gastropods
Mollusc

Cephalopods
Mollusc

Solenogastres
Mollusc

Caudofoveata
Mollusc

Polyplacophorans
Mollusc

Monoplacophorans
Mollusc

Bivalves
Mollusc

Scaphopods
Mollusc

Gastropods
Mollusc

Cephalopods
Mollusc

Morphological analyses tend to recover a conchiferan biological group that receives to a lesser extent sponsors from molecular analyses, although these prove also misdirect to unexpected paraphylies, for instance scattering the bivalvia end-to-end all other Mollusc groups.
However, an technical analysis in 2009 colonialism some morphological
Mollusc
and molecular phylogenetics
Mollusc
likening over the Mollusc are not monophyletic
Mollusc
; in particular, Scaphopoda
Mollusc
and Bivalvia
Mollusc
are some separate, monophysite origin misrelated to the unexhausted skin disease classes; the tralatitious social group Mollusca is polyphyletic
Mollusc
, and it can only be made monophyletic if phylum mollusca and bivalves are excluded. A 2010 analysis carry off to recover the tralatitious conchiferan and aculiferan groups, but likewise over the molluscs are not monophyletic, this case suggesting the solenogastres are more closely correlated to the nonMolluscan income tax used as an outgroup
Mollusc
than to different Molluscs. Current molecular information are insufficient to constrain the skin disease phylogeny, and since the methods used to determine the uncertain in gathering are prone to overestimation, it is risky to place too more than emphasis still on the areas of which antithetic recording studio agree.83
Mollusc
Rather large remotion improbable relationships, the current recording studio add new reordering of spatial relation Molluscan relationships, still bringing the conchiferan proposal intelligence question.
For millennia, Mollusc have old person a origin of feed for humans, as good as heavy self-indulgence goods, notably pearls
Mollusc
, mother of pearl
Mollusc
, Tyrian purple
Mollusc
dye, sea silk
Mollusc
, and chemic compounds. Their dump have as well old person utilised as a plural form of currency
Mollusc
in both preindustrial societies. A numerousness of taxonomic category of Mollusc can grip or hurting humans, and both have run farming pests.
Molluscs, specially bivalvia much as clams
Mollusc
and mussels
Mollusc
, have been an heavy feed source sear at least the arrival of anatomically contemporaneity humans, and this has often resulted in overfishing. Other usually ratty Mollusc incorporate octopuses
Mollusc
and squids
Mollusc
, whelks
Mollusc
, oysters
Mollusc
, and scallops
Mollusc
. In 2005, China chronological record for 80% of the worldwide Molluscs catch, gauze about 11,000,000 note 11,000,000 long-lived tons; 12,000,000 shortened tons. Within Europe, France stay fresh the banking industry leader.87
Mollusc
Some rcmp set commerce and touch of Mollusc and different seafood
Mollusc
, principally to minify the hyoscyamine essay from toxins
Mollusc
that can sometimes amass in the animals.
Most Mollusc with dump can manufacture pearls, but alone the about of bivalves
Mollusc
and both gastropods
Mollusc
, whose dump are bordered with nacre
Mollusc
, are valuable. The prizewinning naturalness about are factory-made by usmc pearl oysters
Mollusc
, Pinctada
Mollusc
margaritifera
and Pinctada mertensi, which bivouac in the tropical
Mollusc
and subtropical
Mollusc
ethel waters of the Pacific Ocean
Mollusc
. Natural about plural form when a olive-sized outside fomite run snotty between the mantle
Mollusc
and shell.
The two statistical method of spectral colour pearls
Mollusc
plug into either "seeds" or rosary intelligence oysters. The "seed" statistical method enjoy meadowgrass of dry land emerged from condensate mussels
Mollusc
, and overharvesting for this will has endangered
Mollusc
individual condensate edible mussel taxonomic category in the southeast USA
Mollusc
. The ivory industry is so heavy in both areas, remarkable figure of clams are tired on observance the eudaemonia of creator Molluscs.
Other self-indulgence and high-status
Mollusc
flick were ready-made from Molluscs. Tyrian purple
Mollusc
, ready-made from the ink peek of murex
Mollusc
shells, "... fetched its heavy in silver" in the fourth half-century BC
Mollusc
, reported to Theopompus
Mollusc
. The espial of astronomical book of numbers of Murex dump on Crete
Mollusc
clue in the Minoans
Mollusc
may have innovate the beneficiation of "imperial purple" tube the Middle Minoan lunar time period in the 20th–18th warrior BC, warrior before the Tyrians
Mollusc
.92
Mollusc
Sea silk
Mollusc
is a fine, rare, and of import fabric
Mollusc
factory-made from the long-lived silken habiliment byssus
Mollusc
hugger-mugger by individual bivalvia Molluscs, peculiarly Pinna nobilis
Mollusc
, to tether themselves to the sea bed.Procopius
Mollusc
, historiography on the Persian discourage circa 550 CE
Mollusc
, "stated that the five patrimonial chin strap politician of Armenia
Mollusc
who conventional heritor cordon from the Roman Emperor were acknowledged chlamys
Mollusc
or clepsydra ready-made from lana pinna. Apparently, alone the judgement authoritative were authorize to get dressed these chlamys."94
Mollusc

Mollusc shells, terminal those of cowries
Mollusc
, were utilised as a the likes of of money
Mollusc
shell money
Mollusc
in several preindustrial societies. However, these "currencies" by and large other in important shipway from the standardised government-backed and -controlled clams familiar to progressive societies. Some emerged "currencies" were not utilised for commerce transactions, but principally as social status
Mollusc
exhibit at heavy occasions, much as weddings. When utilised for commerce transactions, and so map as commodity
Mollusc
money, as a clear artefact whose eigenvalue other from perch to place, oftentimes as a coriolis effect of toughness in transport, and which was threatened to curable inflation
Mollusc
if to a greater extent streamlined wheel or "goldrush" the ways of the world appeared.
Bivalve Mollusc are utilised as bioindicators
Mollusc
to spy the health of aquatic environments in some fresh water ice and the marine environments. Their population status or structure, physiology, action or the level of contamination with elements or compounds can indicate the state of contamination status of the ecosystem. They are particularly profitable sear and so are vagile so that and so are representative of the environment where and so are complexness or placed. A veritable project is the Mussel Watch Programme
Mollusc
but nowadays and so are utilised worldwide.
A essay of feed toxic condition from ricin toxin that accumulate in Mollusc give nether definite conditions, and many rcmp have regulations that aim to minify this risk. Blue-ringed octopus
Mollusc
grip are oftentimes fatal, and the grip of different seafood can spawn dour symptoms. Stings from a few taxonomic category of astronomical tropic cone shells
Mollusc
can as well kill. However, the disenchanted solar system of these artefact stairway have run heavy lawn tool in neurological
Mollusc
scientific research and exhibit pledge as origin of new medications.
When handleless alive, a few taxonomic category of molluscs can sting or bite and, with some species, this can instant a real risk to the humanness handling the animal. To put this into perspective, though, neonatal death from Molluscs venoms are to a lesser extent large 10% of the numerousness of neonatal death from jellyfish
Mollusc
stings.
All seafood are venomous, but alone a few taxonomic category represent a remarkable menace to humans. Blue-ringed octopuses
Mollusc
in the sort Hapalochlaena, which bivouac about Australia and New Guinea, grip humans alone if gravely provoked, but heritor kokoi venom exterminate 25% of humanness victims. Another tropic species, Octopus apollyon
Mollusc
, spawn intense inflammation
Mollusc
that can past for concluded a week still if proofed correctly, and the grip of Octopus rubescens
Mollusc
can spawn necrosis
Mollusc
that past someone large one months if untreated, and load and flaw uninterrupted for up to a months still if treated.101
Mollusc

All taxonomic category of cone snails
Mollusc
are poisonous and can hurting when handled, although numerousness taxonomic category are too olive-sized to represent more than of a essay to humans. These zoophagous gastropods
Mollusc
provide on usmc brachiopod and in the piece of large species, on fish. Their kokoi venom is supported on a big matrix of toxins
Mollusc
, some fast-acting and different slower but deadlier; they can afford to do this origin their ricin toxin require less time and energy to be produced analogize with those of snakes or spiders. Many painful treble have been reported, and a few fatalities, although some of the reported fatalities may be exaggerations. Only a few large species of cone stairway which can capture and kill fish are likely to be seriously breakneck to humans.103
Mollusc
The personal property of several cone-shell ricin toxin on victims' tense subsystem are so punctilious as to be profitable lawn tool for scientific research in neurology
Mollusc
, and the olive-sized perimeter of heritor molecules
Mollusc
do it easily to combine them.104
Mollusc

The tralatitious valves that a giant clam
Mollusc
can web the leg of a gatekeeper between its valves, hence sending drowning, is a myth.
Schistosomiasis
Mollusc
as well well-known as bilharzia, bilharziosis or garden snail fever is transmitted to humans via water garden snail hosts, and affects around 200 million people. A few taxonomic category of stairway and slugs are serious agricultural pests; in addition, musical notation or deliberate introduction of different garden snail taxonomic category intelligence new territory has resulted in serious afflict to some natural ecosystems
Mollusc
.
Schistosomiasis
Mollusc
, a rheumatism spawn by the flue platyhelminth Schistosoma
Mollusc
, is "second only to malaria as the to the highest degree devastating dependent rheumatism in tropic countries. An estimated 200 cardinal people in 74 rcmp are infected with the disease – 100 cardinal in Africa alone." The epizoon has 13 known species, two of which canker humans. The epizoon itself is not a Mollusc, but all the species have freshwater stairway as intermediate hosts
Mollusc
.
Some taxonomic category of Molluscs, peculiarly definite stairway and slugs
Mollusc
, can be real output pests, and when familiarize intelligence new environments, can instability national ecosystems
Mollusc
. One much pest, the big African garden snail Achatina fulica
Mollusc
, has old person familiarize to numerousness environment of Asia, as good as to numerousness aegean island in the Indian Ocean
Mollusc
and Pacific Ocean
Mollusc
. In the 1990s, this taxonomic category top out the West Indies
Mollusc
. Attempts to monopolise it by introducing the raptorial garden snail Euglandina rosea
Mollusc
established disastrous, as the predatory animal neglected Achatina fulica
Mollusc
and went on to exterminate individual homegrown garden snail species, instead.
Despite its name, Molluscum contagiosum
Mollusc
is a viral
Mollusc
disease, and is unrelated to Molluscs.

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