Download - Phylum: Arthropods Arthropods are segmented coelomates with exoskeletons and jointed appendages Arthropods are segmented coelomates with exoskeletons and.

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PhyPhylum: Arthropodslum: ArthropodsArthropods are segmented coelomates with Arthropods are segmented coelomates with

exoskeletonsexoskeletons and and jointed appendagesjointed appendagesThis phylum This phylum is is represented in nearly all represented in nearly all

habitats in the biosphere.habitats in the biosphere.Arthropods are regarded as the most successful Arthropods are regarded as the most successful

animal phylum.animal phylum.The diversity The diversity التنوعالتنوع and successand successوالنجتحوالنجتح of of

arthropods is largely due to three features:arthropods is largely due to three features: - body segmentation - body segmentation الجسم الجسم تعقل ,,تعقل - a hard exoskeleton - a hard exoskeleton صلب خارجي صلب جليج خارجي , ,جليج - and jointed appendages - and jointed appendages مفصلية مفصلية زوائد ..زوائد

Lecture 17: Animal ClassificationLecture 17: Animal Classification

The body of an arthropod is completely The body of an arthropod is completely covered by the covered by the cuticlecuticle, an , an exoskeletonexoskeleton constructed from layers of protein and chitin.constructed from layers of protein and chitin.

The The exoskeletonexoskeleton of arthropods is strong and of arthropods is strong and relatively impermeable to water.relatively impermeable to water.

Arthropods have well-developed sense organs, Arthropods have well-developed sense organs, including including eyeseyes for vision, for vision, olfactoryolfactory receptors receptors for smell, and for smell, and antennaeantennae for touch and smell. for touch and smell.

Arthropods have an Arthropods have an open circulatory system open circulatory system in which hemolymph fluid is propelled by a in which hemolymph fluid is propelled by a heart through short arteries into sinuses (the heart through short arteries into sinuses (the hemocoelhemocoel) surrounding tissues and organs.) surrounding tissues and organs.

Arthropods have evolved a variety of Arthropods have evolved a variety of specialized organs for gas exchange.specialized organs for gas exchange.

PhyPhylum: Arthropodslum: Arthropods

PhyPhylum: Arthropodslum: Arthropods

• They have clawlike feeding appendages, cheliceraechelicerae, crustaceans have jawlike mandiblesmandiblesفكوكفكوك .

• Have sensory antennaeantennae قرون قرون and usually a pair of استشعاراستشعارcompoundcompound eyeseyes مركبة inأعينaddition to simple eyes.

• Arthropods have been grouped into the phylum Arthropoda.

1-Class Arachnida1-Class Arachnida طائفة طائفة العنكبياتالعنكبيات

These include These include scorpionsscorpionsالعقاربالعقارب , , spidersspidersالعناكبالعناكب , , ticksticksالقرادالقراد , and , and mitesmitesالحلمالحلم ..

Nearly all ticks are blood-Nearly all ticks are blood-suckingsucking للدماء للدماء ماص parasites on the parasites on the ماصbody surfaces of most animals.body surfaces of most animals.

In most spiders, respirationIn most spiders, respirationالتنفسالتنفس is carried out by book lungsis carried out by book lungs الرئة الرئة . . الكتابيةالكتابية

2-class Insecta2-class Insecta الحشرات الحشرات طائفة طائفة

They live in almost every terrestrial habitat and in They live in almost every terrestrial habitat and in fresh water, and flying insects fill the air.fresh water, and flying insects fill the air.

The study of insect, (The study of insect, (EntomologyEntomology)) is a vast field with is a vast field with many subspecialties, including many subspecialties, including physiologyphysiology, , ecologyecology, , and and taxonomytaxonomy….etc.….etc.

Class InsectaClass Insecta is divided into about 26 orders. is divided into about 26 orders.

•Many insects have Many insects have one or two pairs of one or two pairs of wingswings that emerge that emerge from the from the dorsal side dorsal side of the thoraxof the thorax..

The Insects750,000 + species insects

described, but may be 30 million species undescribed.

Many adaptations make insects one of the most successful terrestrial animals.Exoskeleton for water

conservationTracheal System for gas exchangeMetamorphosisMany types of mouth partsFlight

Fig. 33.33

رأرأسس

صدصدرر

بطبطنن

قرون قرون استشعاراستشعار

مركبة مركبة عين عين

Modified mouthparts have allowed insects to diversify and take advantage of many different food sources.

Modify generic structures for various food sources.

Generalized Insect Mouthparts

Specialized Mouthparts

The internal anatomy of an insect includes The internal anatomy of an insect includes

several complex organ systems.several complex organ systems.

In the In the complete digestive systemcomplete digestive system, there are , there are

regionally specialized organs with discrete regionally specialized organs with discrete

functions.functions.

Metabolic wastes are removed from the Metabolic wastes are removed from the

hemolymphhemolymphالدمالدم by by MalpighianMalpighian tubulestubules ملبيجي ملبيجي أنابيب , , أنابيب

outpockets of the digestive tract.outpockets of the digestive tract.

Respiration is accomplished by a branched, chitin-Respiration is accomplished by a branched, chitin-

lined lined tracheal systemtracheal system القصبي القصبي الجهاز that carries Othat carries O22 from from الجهاز

the spiracles directly to the cells.the spiracles directly to the cells.

The insect The insect nervous systemnervous system consists of a pair of consists of a pair of

ventral nerve cordsventral nerve cords بطنيين عصبيين بطنيين حبلين عصبيين with several with several حبلين

segmental ganglia. segmental ganglia.

3 Kinds of Insect MetamorphosisAmetabolous Metamorphosis – only

difference between larvae and adult are size; both are wingless. Silverfish, Order Thysanura.

After Flight…Hemimetabolous Metamorphosis –

develop from egg to adult has several stages (instars) with smaller versions of adults called nymphs. Immature nymphs have no wings or genitalia until adult.

Incomplete or Hemimetabolous Metamorphosis

Holometabolous Metamorphosis – after hatching from egg, immatures are called larvae (very different body form than adult). After several instars, the last larval molt forms a pupa – undergoes radical body form change.Protective case may enclose pupal stage:

Moths use silk to make a cocoon. Butterflies use the larval exoskeleton to make a

chrysalis.

Adult emerges from case very different in body form – eclosion.

Complete or Holometabolous Metamorphosis

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