arthropods & echinoderms. phylum arthropoda well-known subdivisions of phylum arthropoda class...

ArthropodArthropods s & &

EchinoderEchinodermsms

Phylum Phylum ArthropodaArthropoda

Well-Known Subdivisions of Well-Known Subdivisions of Phylum ArthropodaPhylum Arthropoda

Class ArachnidaClass Arachnida Order Scorpiones (scorpions)Order Scorpiones (scorpions) Order Opiliones (daddy-longlegs)Order Opiliones (daddy-longlegs) Order Acari (mites & ticks)Order Acari (mites & ticks) Order Araneae (spiders)Order Araneae (spiders)

Class Chilopoda (centipedes)Class Chilopoda (centipedes) Class Diplopoda (millipedes)Class Diplopoda (millipedes) Class InsectaClass Insecta (insects)(insects)

EvolutionEvolution

Precambrian seas over 600 million Precambrian seas over 600 million years agoyears ago

well established by 500 million years well established by 500 million years agoago

Constantly evolvingConstantly evolving very diverse phylumvery diverse phylum

SymmetrySymmetry

Bilaterally symmetricalBilaterally symmetrical Advantages:Advantages:

Specialization of body organs Specialization of body organs CephalizationCephalization Efficient movementEfficient movement

Defined direction of movementDefined direction of movement Less resistance to water and substancesLess resistance to water and substances Finding food, mating, avoiding predatorsFinding food, mating, avoiding predators

Body CavityBody Cavity

CoelomateCoelomate mesoderm lines body cavity and mesoderm lines body cavity and

surrounds and supports the endodermic surrounds and supports the endodermic gutgut

mesoderm forms tissues of attachment mesoderm forms tissues of attachment for organs located in coelom (liver, for organs located in coelom (liver, lungs, etc.)lungs, etc.)

Structural SupportStructural Support ExoskeletonExoskeleton

3 Layers: 3 Layers: Waxy outer layer made up of proteins and Waxy outer layer made up of proteins and

lipids; repels water; helps prevent drying lipids; repels water; helps prevent drying outout

Middle layer provides primary protection; Middle layer provides primary protection; made of protein and chitin; sometimes made of protein and chitin; sometimes calcium carbonatecalcium carbonate

Inner layer contains protein and chitin; Inner layer contains protein and chitin; flexible at joints- allows arthropod to move flexible at joints- allows arthropod to move freely;freely;

Muscles attached to inner layer at joints Muscles attached to inner layer at joints move body segments move body segments

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Parts of a CrayfishParts of a Crayfish SensorySensory- antennules, - antennules,

antennaeantennae DefenseDefense- chelipeds- chelipeds FeedingFeeding- mandible, - mandible,

mouth, maxillipeds, mouth, maxillipeds, maxillamaxilla

WalkingWalking- walking - walking legslegs

SwimmingSwimming- - swimmerets, uropodsswimmerets, uropods



AppendageAppendage FunctionFunction

AntennuleAntennule Touch, taste, equilibriiumTouch, taste, equilibriium

AntennaAntenna Touch, tasteTouch, taste

MandibleMandible Chew foodChew food

MaxillaMaxilla Manipulate food, draw water Manipulate food, draw water currents over gillscurrents over gills

MaxillipedMaxilliped Touch, taste, manipulate Touch, taste, manipulate foodfood

ChelipedCheliped Capture food, defenseCapture food, defense

Walking legWalking leg Locomotion over solid Locomotion over solid surfacessurfaces

SwimmeretSwimmeret Create water currents, Create water currents, transfer sperm (males), carry transfer sperm (males), carry

eggs and young (females)eggs and young (females)

UropodUropod Propulsion during tailflipsPropulsion during tailflips

Nutrition & DigestionNutrition & Digestion Crayfish (crustacean):Crayfish (crustacean):

DIET: omnivores; they eat plants, animals, and decaying DIET: omnivores; they eat plants, animals, and decaying organismsorganisms

Ex: shrimp, fish, water plants, plankton, insectsEx: shrimp, fish, water plants, plankton, insects food passes through esophagus to stomachfood passes through esophagus to stomach teeth made of chitin and calcium carbonate grind food teeth made of chitin and calcium carbonate grind food

into fine pasteinto fine paste enzymes secreted by digestive gland mix pasteenzymes secreted by digestive gland mix paste Paste enters intestine and digestive gland for further Paste enters intestine and digestive gland for further

digestion and absorptiondigestion and absorption indigestible material leaves through anusindigestible material leaves through anus

Nutrition and Digestion Nutrition and Digestion (cont.)(cont.)

Scorpions:Scorpions: DIET: mainly insects and spidersDIET: mainly insects and spiders

Spiders:Spiders: DIET: mainly insects; some can eat fish, frogs, or birds; DIET: mainly insects; some can eat fish, frogs, or birds;

consume body fluids of preyconsume body fluids of prey Similar digestive system to crustaceans (like crayfish)Similar digestive system to crustaceans (like crayfish)

Parasitic mites: suck fluids from leaves of fruit trees; feed Parasitic mites: suck fluids from leaves of fruit trees; feed on blood, dead skin, hair, and feathers of vertebrates, like on blood, dead skin, hair, and feathers of vertebrates, like humans, cattle, and dogshumans, cattle, and dogs

Parasitic ticks: feed on blood of hostParasitic ticks: feed on blood of host Millipedes: use mandibles and maxillae to chew on plants Millipedes: use mandibles and maxillae to chew on plants

and decaying plant matterand decaying plant matter Centipedes: use poisonous claws to kill prey (earthworms, Centipedes: use poisonous claws to kill prey (earthworms,

insects, etc.) and use mandibles and maxillae to tear apart insects, etc.) and use mandibles and maxillae to tear apart foodfood

TransportationTransportation

Some are sessile as adultsSome are sessile as adults Ex: BarnaclesEx: Barnacles

Isopods: “equal legs”Isopods: “equal legs” Have 7 pairs of identical legsHave 7 pairs of identical legs Ex: sow bugs, pill bugsEx: sow bugs, pill bugs

Decapods: “ten feet”Decapods: “ten feet” 5 pairs of legs5 pairs of legs Ex: crayfish, lobsters, shrimps, crabsEx: crayfish, lobsters, shrimps, crabs

Transportation (cont.)Transportation (cont.) Tailflip: muscles of a crustacean (such as a Tailflip: muscles of a crustacean (such as a

crayfish) can bend the abdomen and propel it crayfish) can bend the abdomen and propel it backwards very rapidlybackwards very rapidly Uropods on the abdomen of a crayfish help propel Uropods on the abdomen of a crayfish help propel

crayfish during tailflipscrayfish during tailflips Arachnids: have 4 pairs of walking legsArachnids: have 4 pairs of walking legs

Ex: spiders, scorpions, mites, ticksEx: spiders, scorpions, mites, ticks Mites and ticks can also be parasiticMites and ticks can also be parasitic

Myriapods: Myriapods: Millipedes have 2 pairs of legs on each body segment Millipedes have 2 pairs of legs on each body segment

except the last two; move slowlyexcept the last two; move slowly Centipedes have anywhere from 15 to 175 pairs of Centipedes have anywhere from 15 to 175 pairs of

legs; can move quicklylegs; can move quickly

CirculationCirculation All have open circulatory systemsAll have open circulatory systems Crustaeans:Crustaeans:

Dorsal heart pumps hemolymph into blood vesselsDorsal heart pumps hemolymph into blood vessels Vessels carry it to different parts of bodyVessels carry it to different parts of body Hemolymph leaves vessels, enters hemocoel and surrounds Hemolymph leaves vessels, enters hemocoel and surrounds

tissuestissues Passes through the gills, where it exchanges COPasses through the gills, where it exchanges CO2 2 and Oand O22 with with

HH2200 Hemolymph returns from gills to dorsal heartHemolymph returns from gills to dorsal heart

Spider’s and scorpion’s circulatory systems are Spider’s and scorpion’s circulatory systems are similar to crustaceanssimilar to crustaceans

Respiration/Gas Respiration/Gas ExchangeExchange

Crustaceans:Crustaceans: All except smallest crustaceans use gillsAll except smallest crustaceans use gills

Small crustaceans- COSmall crustaceans- CO2 2 and Oand O2 2 diffuse through thin parts diffuse through thin parts of the exoskeletonof the exoskeleton

Gills extend from base of each walking leg into a Gills extend from base of each walking leg into a chamber under carapacechamber under carapace

Legs circulate water across gills as the crustacean Legs circulate water across gills as the crustacean walks walks

Feathery branches on maxillae also help direct water Feathery branches on maxillae also help direct water over gillsover gills

A thin extension of the exoskeleton covers each A thin extension of the exoskeleton covers each gill and permits gases to diffuse across gill surfacegill and permits gases to diffuse across gill surface

Respiration/Gas Exchange Respiration/Gas Exchange (cont.)(cont.)

Spiders:Spiders: Book lungs- paired sacs in abdomen with Book lungs- paired sacs in abdomen with

several parallel foldsseveral parallel folds Like pages in a bookLike pages in a book Allow for large surface area for efficient gas Allow for large surface area for efficient gas

exchangeexchange Tracheae- tubes that carry air from Tracheae- tubes that carry air from

openings in the exoskeleton to tissues in openings in the exoskeleton to tissues in the bodythe body

Openings- spiraclesOpenings- spiracles Some spiders have either book lungs or Some spiders have either book lungs or

tracheae, and some have bothtracheae, and some have both

Water Balance/ExcretionWater Balance/Excretion Crayfish:Crayfish:

Hypertonic to environmentHypertonic to environment Excess water eliminated by Excess water eliminated by green glands-green glands-

excretory organsexcretory organs Water and other fluids leave crayfish Water and other fluids leave crayfish

through a pore at the base of the antennae through a pore at the base of the antennae Spiders: Spiders:

Malphighian tubules-Malphighian tubules- hollow projections hollow projections of the digestive tract that carry body fluids of the digestive tract that carry body fluids and wastes to the intestineand wastes to the intestine

Help spiders conserve waterHelp spiders conserve water Some spiders have coxal glandsSome spiders have coxal glands

Remove wastes through openings at the base of Remove wastes through openings at the base of the spider’s legsthe spider’s legs

Reproduction/Reproduction/DevelopmentDevelopment

Crustaceans:Crustaceans: Mate in fallMate in fall Male transfers sperm to female using first and second Male transfers sperm to female using first and second

swimmeretsswimmerets Sperm fertilize eggs and are released in spring; eggs stay Sperm fertilize eggs and are released in spring; eggs stay

on the female’s swimmeretson the female’s swimmerets Eggs hatch after 6 weeksEggs hatch after 6 weeks Have several larval stagesHave several larval stages

Naupilus- free-swimming larva; has one eye and three Naupilus- free-swimming larva; has one eye and three pairs of appendagespairs of appendages

Emerge from larval stages as a smaller version of adult Emerge from larval stages as a smaller version of adult firmfirm

Molt 7 times first year; molte 2 times in their remaining lifeMolt 7 times first year; molte 2 times in their remaining life

Reproduction/Development Reproduction/Development (cont.)(cont.)

Spiders:Spiders: Mature male transfers sperm to pedipalp sacsMature male transfers sperm to pedipalp sacs Male places sperm in female’s seminal Male places sperm in female’s seminal

receptaclereceptacle Male must leave as soon as mating is finished- female Male must leave as soon as mating is finished- female

might eat him otherwisemight eat him otherwise Female fertilizes eggs and passes them into a Female fertilizes eggs and passes them into a

cocoon which she spins herselfcocoon which she spins herself She will either carry the case around or attach it to a She will either carry the case around or attach it to a

plant or webplant or web Spiders undergo their first molt within two Spiders undergo their first molt within two

weeks of entering the cocoon; they leave the weeks of entering the cocoon; they leave the cocoon after those two weekscocoon after those two weeks

Can grow to as large as 9 cm longCan grow to as large as 9 cm long

Unique CharacteristicsUnique Characteristics & Interesting Facts& Interesting Facts

Arthropods make up 75% of all animals!Arthropods make up 75% of all animals! Centipedes can have anywhere from 15 to 175 pairs of legs!Centipedes can have anywhere from 15 to 175 pairs of legs! Arthropods go through a process called moltingArthropods go through a process called molting

Their exoskeleton cannot grow, so they have to Their exoskeleton cannot grow, so they have to periodically shred it in order to get largerperiodically shred it in order to get larger

Copepods, crustaceans that are less than a centimeter long, Copepods, crustaceans that are less than a centimeter long, are the most abundant animals in the ocean. There are so are the most abundant animals in the ocean. There are so many of them that they outweigh all the whales on Earth!many of them that they outweigh all the whales on Earth!





Unique CharacteristicsUnique Characteristics& Interesting Facts& Interesting Facts



Only arthropods have all five characteristics!

Subphylum CrustaceaSubphylum Crustacea

Procambarus fallaxProcambarus fallax

Pond crayfishPond crayfish



Class ArachnidaClass Arachnida

Nephila clavipesNephila clavipes

Golden Silk Banana Golden Silk Banana SpiderSpider





Pandinus imperator

Black Emperor Scorpion

Class DiplopodaClass Diplopoda

Deseret MillipedeDeseret Millipede

Orthoporus ornatusOrthoporus ornatus





Class Chilopoda

Desert Millipede

Scolopendra

SubphyluSubphylumm

InsectaInsecta

Symmetry/Body Cavity/Symmetry/Body Cavity/Structural SupportStructural Support

All insects have bilateral symmetryAll insects have bilateral symmetry Insects are coelomate arthopodsInsects are coelomate arthopods hard exoskeleton of insects allows hard exoskeleton of insects allows

for structural support of musclesfor structural support of muscles thorax provides structural support thorax provides structural support

for the legs and, if present, wings. for the legs and, if present, wings.

Nutrition/DigestionNutrition/Digestion

Insects obtain nutrients from the food Insects obtain nutrients from the food they eatthey eat

three regions in the digestive systemthree regions in the digestive system foregut foregut (stomodeum)(stomodeum) midgut midgut (mesenteron)(mesenteron) hindgut hindgut (proctodeum)(proctodeum)

All insects have a All insects have a complete digestive complete digestive systemsystem food processing occurs within the food processing occurs within the

alimentary canal,alimentary canal, a tube-like enclosure, a tube-like enclosure, which runs lengthwise through the bodywhich runs lengthwise through the body

Ingested food travels in only one directionIngested food travels in only one direction

Nutrition/Digestion Nutrition/Digestion (cont.)(cont.)

An Insect’s An Insect’s mouth mouth is specializedis specialized Grasshopper’s mouths are used for Grasshopper’s mouths are used for

cutting and chewing leaves and blades of cutting and chewing leaves and blades of grassgrass

Labrum & Labium:Labrum & Labium: mouth parts that mouth parts that function and upper and lower lipsfunction and upper and lower lips

Mosquitoes have long, thin mouth parts Mosquitoes have long, thin mouth parts used for piercing flesh and sucking bloodused for piercing flesh and sucking blood

Flies have soft, sponge-like mouths used Flies have soft, sponge-like mouths used for soaking up liquids, such as fruit juicesfor soaking up liquids, such as fruit juices

Digestion/ExcretionDigestion/Excretion food enters the mouth and passes through the food enters the mouth and passes through the

esophagus to the cropesophagus to the crop Moistened by saliva from salivary glandsMoistened by saliva from salivary glands

Food then travels to the gizzard where it is Food then travels to the gizzard where it is shreddedshredded

Shredded food moves to the midgut where Shredded food moves to the midgut where nutrients are absorbed through the wall and nutrients are absorbed through the wall and into the coelom into the coelom Gastric ceca:Gastric ceca: pockets that branch from the pockets that branch from the

digestive track which secrete enzymesdigestive track which secrete enzymes Any undigested material travels to the Any undigested material travels to the

hindgut and exits the body through the anus hindgut and exits the body through the anus

StomodaeuStomodaeumm

Mesenteron

Proctodeum

CirculationCirculation All insects have an open circulatory All insects have an open circulatory

system system responsible for movement of nutrients, responsible for movement of nutrients,

salts, hormones, and metabolic wastes salts, hormones, and metabolic wastes Large dorsal vessel (aorta) carries Large dorsal vessel (aorta) carries

hemolymph through the insect’s body hemolymph through the insect’s body The heart, located in the abdomen and The heart, located in the abdomen and

thorax, pumps hemolymph to the “head” thorax, pumps hemolymph to the “head” of the insectof the insect

The hemolymph then moves back The hemolymph then moves back through the coelom and reenters the through the coelom and reenters the heart through small poresheart through small pores

TransportationTransportation

Insects have three pairs of jointed Insects have three pairs of jointed legs legs

Most have one or two pairs of wingsMost have one or two pairs of wings Grasshopper:Grasshopper:

Two pairs of walking legs Two pairs of walking legs One pair of hind legsOne pair of hind legs

Used for jumpingUsed for jumping Two pairs of wingsTwo pairs of wings

Gas Gas Exchange/RespirationExchange/Respiration

All insects are aerobic organismsAll insects are aerobic organisms respiratory system transports respiratory system transports

carbon dioxide and oxygen carbon dioxide and oxygen separate from the circulatory separate from the circulatory

system system Insects use aInsects use a tracheal system tracheal system, ,

complex network of tubes that complex network of tubes that brings oxygen-containing air all brings oxygen-containing air all around the bodyaround the body

Gas Exchange/Respiration Gas Exchange/Respiration (cont.)(cont.)

Air enters the body through Air enters the body through spiraclesspiracles, , valve-like openings in the exoskeleton valve-like openings in the exoskeleton located along the thorax and abdomen of located along the thorax and abdomen of most insectsmost insects

Air travels through the tracheae which Air travels through the tracheae which have ends filled with fluidhave ends filled with fluid

Oxygen diffuses through the fluid and Oxygen diffuses through the fluid and into the cellsinto the cells

Carbon dioxide diffuses the opposite wayCarbon dioxide diffuses the opposite way

Water BalanceWater Balance The exoskeleton contains a waxy covering The exoskeleton contains a waxy covering

which helps to keep moisture in which helps to keep moisture in Insects can lose water in 3 ways by evaporationInsects can lose water in 3 ways by evaporation

general surface of the body wallgeneral surface of the body wall spiracular systemspiracular system bothboth

Some insects keep their spiracles closed to Some insects keep their spiracles closed to conserve water only opening them to receive conserve water only opening them to receive enough oxygenenough oxygen

Malphighian Tubes:Malphighian Tubes: collect water and collect water and cellular wastes from the hemolymph as well as cellular wastes from the hemolymph as well as return water to the hemolymphreturn water to the hemolymph

ReproductionReproduction All insects have separate sexesAll insects have separate sexes Male places sperm in female’s seminal Male places sperm in female’s seminal

receptacle, and they are stored there receptacle, and they are stored there until eggs are released by the ovariesuntil eggs are released by the ovaries

Eggs are fertilized internallyEggs are fertilized internally In grasshoppers, the female has an In grasshoppers, the female has an

ovipositor on the last segment of her ovipositor on the last segment of her abdomenabdomen Ovipositor:Ovipositor: organ which the female organ which the female

grasshopper uses to dig a hole in the grasshopper uses to dig a hole in the ground to lay the fertilized eggsground to lay the fertilized eggs

DevelopmentDevelopment

After hatching, a young insect After hatching, a young insect must molt several times before must molt several times before becoming fully maturebecoming fully mature

Most insects go through Most insects go through metamorphosis, metamorphosis, a a developmental change in formdevelopmental change in form

Two main kinds: incomplete Two main kinds: incomplete and completeand complete

Development (cont.)Development (cont.) incompleteincomplete

A A nymphnymph, an immature version of the adult, is hatched , an immature version of the adult, is hatched from the egg, gradually develops into an adultfrom the egg, gradually develops into an adult

Grasshoppers, mayflies, dragonflies, and termites undergo Grasshoppers, mayflies, dragonflies, and termites undergo incomplete metamorphosisincomplete metamorphosis

CompleteComplete Worm-like larvae hatches from the eggWorm-like larvae hatches from the egg Exoskeleton falls off and larvae develops into a Exoskeleton falls off and larvae develops into a pupapupa, ,

stage of development where the larvae becomes an adultstage of development where the larvae becomes an adult After metamorphosis is complete, the pupa molts into a After metamorphosis is complete, the pupa molts into a

mature adultmature adult Butterflies, moths, and bees undergo complete Butterflies, moths, and bees undergo complete

metamorphosismetamorphosis

Unique CharacteristicsUnique Characteristics& Interesting Facts& Interesting Facts

95% of all the animal species on the earth 95% of all the animal species on the earth are insects are insects

one out of every four animals on earth is a one out of every four animals on earth is a beetle beetle

Scientists estimate that 10% of the animal Scientists estimate that 10% of the animal biomass of the world is ants, and another biomass of the world is ants, and another 10% is termites10% is termites

About About 1,000,000,000,000,000,000 (1,000,000,000,000,000,000 (a a billion billion) insects are alive at any time. billion billion) insects are alive at any time. This is about 160 million insects for each This is about 160 million insects for each person on Earth! person on Earth!

Monarch Monarch ButterflyButterfly

Order: Order: LepidopteraLepidoptera

Scientific Name:Scientific Name:Danaus plexippusDanaus plexippus

Honey BeeHoney Bee

Order:Order:

HymenopteraHymenoptera

Scientific Scientific Name:Name:

Apis melliferaApis mellifera

Common House Common House MosquitoMosquito

Order: dipteraOrder: diptera

Scientific Scientific Name:Name:

Culex pipiens Culex pipiens pallenspallens

arthropods & echinoderms. phylum arthropoda well-known subdivisions of phylum arthropoda class...

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pairs of walking legsex

pairs of identical legsex

feet5 pairs of legsex

water plants

body segments parts

digestive gland

calcium carbonateinner

crayfishparasitic mites