Nonc hordate evolution

7/23/2019 Nonc hordate evolution

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PA PER III

(Non-chordates, Evolution andEconomic Zoology)

Unit-I: - Introduction to classifcation:General study o Non-hordate !hylas

u" to #u$class %ith e&am"les: -'rthro"oda, ollusca, Echinodermata

and emichordata*


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ARTHROPODA

Largest Phylum - 900,000species

bilaterally Symmetrical,

Triploblastic(tube within a tube plan) Coelomates

Organization with Organ system grade

Body -metamerically segmented - a pair of appendages on eachsegment

Body co!ered by chitinous cuticle - e&os+eleton Head- se!eral fused segments with appendages which are modi"ed

to ser!e as'ntennae, mouth"artsor"incers(chelicerae) #ue to!aried en!ironment, the mouthparts are also of di$erent !arieties

%rthropods ha!e !ariety of Respiratory Organs

&arine forms ha!e ' gills' ighly !ascularized, con!oluted, thin

walled tissue suited for gas echange*errestrial forms ha!e ' $oo+ lungsseen in spiders, or air tubescalled as tracheaewhich help ion rapid transport of oygen directlyto the cells of the body

*hey possess o"en circulatory systemwith a dorsal heart, blood

!essels widening into blood "lled spaces called as sinuses+


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Arthropoda *he ecretion taes place with special tubules called as al"ighian

tu$ules

*hey possess sense organsof !arious types 'ntennaeor feelers woring as tactile organs

Eyes with photoreceptors in insects the eyes are compound in nature withmany units called as ommatidia

#tatocystsorgans of balance

aste rece"tors in insets are present in legs

#ound rece"tors in cricets !heromoneswhich help ion chemical communication

%rthropods are Unise&ual generally fertilization is internalbut insome a.uatic members it is external &ale deposits sperm in thefemale se organ Land arthropods show internal fertilizationOiparo!s' lay eggs /n #cor"ion the eggs hatch inside female

body *herefore, they appear to gi!e birth to young ones "olting0 &a1or character of arthropods2 success is metamor"hosis

' big changes in form and physiology that occur in immature stage,larvaand con!erts it into'dult Lar!a and adult di$er in not onlyappearance but also their diet and en!ironment where they li!e, thusreducing competition and enhances chances of sur!i!al along with

others3


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Arthropoda

CL#$$%&%C#T%O' Based on the body di!isions and

presence or absence of certainspeci"c appendages Phylum

%rthropoda has been classi"ed into"!e classes

4lass 5 4rustacea0

4lass + Branchiopoda 4lass 3 4ephalocarida

4lass 6 &aillopoda

4lass 7 8emipedia 6


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Arthropoda

$!bphyl!m )Trilobitomorpha

Class Trilobita* trilobites +extinct *rilobites are earliest nown groups of

arthropods *he "rst appearance of trilobites isaround -.)million years ago, and they

9ourished throughout the lower /aleozoicerabut during the eonian, all trilobite ordersecept /roetidadied out *rilobites "nallydisappeared in the massextinctionat the endof the /ermianabout .-0million years ago

*he trilobites were among the most successfulof all early animals, roaming the oceans foro!er .10 million years2

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http://en.wikipedia.org/wiki/Trilobitomorphahttp://en.wikipedia.org/wiki/Trilobitahttp://tools.wmflabs.org/timescale/?Ma=521http://en.wikipedia.org/wiki/Myrhttp://en.wikipedia.org/wiki/Paleozoichttp://en.wikipedia.org/wiki/Devonianhttp://en.wikipedia.org/wiki/Proetidahttp://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_eventhttp://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_eventhttp://en.wikipedia.org/wiki/Permianhttp://tools.wmflabs.org/timescale/?Ma=250http://en.wikipedia.org/wiki/Myrhttp://en.wikipedia.org/wiki/Myrhttp://tools.wmflabs.org/timescale/?Ma=250http://en.wikipedia.org/wiki/Permianhttp://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_eventhttp://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_eventhttp://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_eventhttp://en.wikipedia.org/wiki/Proetidahttp://en.wikipedia.org/wiki/Devonianhttp://en.wikipedia.org/wiki/Paleozoichttp://en.wikipedia.org/wiki/Myrhttp://tools.wmflabs.org/timescale/?Ma=521http://en.wikipedia.org/wiki/Trilobitahttp://en.wikipedia.org/wiki/Trilobitomorpha


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Arthropoda

;


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Arthropoda

8xamples horseshoe crabs, scorpions, spiders, mites,harestmen, tic4s, and $olif!gae
http://en.wikipedia.org/wiki/Horseshoe_crabhttp://en.wikipedia.org/wiki/Scorpionhttp://en.wikipedia.org/wiki/Spiderhttp://en.wikipedia.org/wiki/Mitehttp://en.wikipedia.org/wiki/Harvestmenhttp://en.wikipedia.org/wiki/Tickhttp://en.wikipedia.org/wiki/Solifugaehttp://en.wikipedia.org/wiki/Solifugaehttp://en.wikipedia.org/wiki/Tickhttp://en.wikipedia.org/wiki/Harvestmenhttp://en.wikipedia.org/wiki/Mitehttp://en.wikipedia.org/wiki/Spiderhttp://en.wikipedia.org/wiki/Scorpionhttp://en.wikipedia.org/wiki/Horseshoe_crab


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Class 1M erostom atahorseshoe crabs,eurypterids(eti!ct" "erostomatais the name gi!en to a

grouping of theetinct ?urypterida (sea scorpions) andthe @iphosura (horseshoe crabs)

5A
http://en.wikipedia.org/wiki/Merostomatahttp://en.wikipedia.org/wiki/Merostomatahttp://en.wikipedia.org/wiki/Horseshoe_crabhttp://en.wikipedia.org/wiki/Horseshoe_crabhttp://en.wikipedia.org/wiki/Eurypteridhttp://en.wikipedia.org/wiki/Eurypteridhttp://en.wikipedia.org/wiki/Eurypteridhttp://en.wikipedia.org/wiki/Horseshoe_crabhttp://en.wikipedia.org/wiki/Merostomata


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CL#$$ . /:C'O;O'%# * $8# $/%8R$

Sea spiders, also calledPantopodaorpycnogonids,

are marine arthropods of class Pycnogonida. They arecosmopolitan, found especially in theMediterraneanandCaribbean Seas, also in theArcticandAntarctic Oceans.There are over 1300 no!n species, ran"in" in si#e from 1to 10 millimeters $0.03% to 0.3%&in' to over %0cm $3(in'in some deep !ater species.

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http://en.wikipedia.org/wiki/Arthropodhttp://en.wikipedia.org/wiki/Class_(biology)http://en.wikipedia.org/wiki/Cosmopolitan_distributionhttp://en.wikipedia.org/wiki/Mediterranean_Seahttp://en.wikipedia.org/wiki/Caribbean_Seahttp://en.wikipedia.org/wiki/Arctic_Oceanhttp://en.wikipedia.org/wiki/Antarctic_Oceanhttp://en.wikipedia.org/wiki/Antarctic_Oceanhttp://en.wikipedia.org/wiki/Arctic_Oceanhttp://en.wikipedia.org/wiki/Caribbean_Seahttp://en.wikipedia.org/wiki/Mediterranean_Seahttp://en.wikipedia.org/wiki/Cosmopolitan_distributionhttp://en.wikipedia.org/wiki/Class_(biology)http://en.wikipedia.org/wiki/Arthropod


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Subphylum #M yriapodaClassChilopodace!tipedes

Centipedes belong to class Chilopoda of the

s!bphyl!m "yriapoda2 They are elongated

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Nonc hordate evolution