Transcript Phylum Arthropoda - Moore Public Schools

Phylum Arthropoda
Zoology 2015-2016
Mrs. Wyatt
Why have Arthropods Achieved such great
Diversity and Abundance?
• A versatile exoskeleton
• formed by a cuticle secreted by the underlying epidermis
• impregnated with calcium salts which reduces flexibility but increases
strength
• to grow an Arthropod must shed its exoskeleton in a process called
ecdysis
• Segmentation and Appendages provide for more efficient locomotion
– Many times, segments are fused into functional groups called
tagmata
• Air piped directly to cells
– Terrestrial arthropods have a tracheal system of air tubes
– Aquatic arthropods have some type of gills
Why have Arthropods Achieved such great
Diversity and Abundance?
• Highly developed sensory organs
– Compound (mosaic) eye
– Organs of smell, hearing, balancing, and chemical receptors
• Complex behavior patterns
– innate behavior controls much of their lives
– Some insects show learning behavior
Why have Arthropods Achieved such great
Diversity and Abundance?
• Use of diverse resourses through metamorphosis
– Larval forms often are adapted to eating different foods than the
adult
– And adults often occupy a different space or niche.
General Characteristics
• Largest and most diverse phylum with
approximately 1.1million species classified
and possible 100 million more to classify
• All representatives of the Arthropod phylum
possess an exoskeleton containing proteins
and chitin which is a complex polysaccharide.
This structure supports and protects internal
structures. Arthropods show metamerism
(segmentation) but most metameres are
arranged into functional groups called
tagmata. The exoskeleton is molted
periodically to allow growth to occur, this is
called ecdysis. This shedding of the cuticle
occurs between 2 and 10 times before
reaching adulthood
General Characteristics
• Arthropods have an open circulatory system with a dorsal heart that
pumps blood and lymph to a hemocoel body cavity
General Characteristics
• Most arthropods are dioecious with internal fertilization.
Many arthropods undergo various types of metamorphosis
that convert juvenile forms to adult forms, this limits
interspecies competition because juveniles usually occupy a
different niche than adults
Complete Metamorphosis
General Characteristics
• Arthropod appendages are jointed with hinge-like
connections that make complex limb movements possible.
Some appendages are modified for special functions:
– Examples:
Swimmerets of Crayfish
Chelicerae of Spiders
General Characteristics
• Respiration is conducted by gills, book gills, book lungs, or
trachea (air tubes)
Respiratory System of
Grasshopper
Comparative Diagram of
Aquatic vs. Terrestrial
Reparatory System of
Arthropods
General Characteristics
• Excretion is by gills, antennal glands , malphighian tubules
• Or trachae
Antennal Glands in Crustacea
Malpighian Tubules in Grasshopper
General Characteristics
• Nervous system is a dorsal brain connected to ventral
ganglia. Well developed sense organs for sight, smell, touch,
taste, chemoreceptors and direction. Some species have a
compound mosaic eye
Compound mosaic eye of
arthropod
General Characteristics
• Complete digestive system with special mouthparts
modified for different methods of feeding
Comparative Diagram
Insecta Mouth Parts
General Characteristics
• Complex behavior in organization and
activity. Innate behavior controls much of
their lives but learning also plays in
important role in the lives of many
Representative Arthropoda
Subphyla & Classes
• Subphylum Trilobita – 4000 species identified, all are now extinct for
200 million years. Left a rich fossil record.
Trilobite Fossils
Representative Arthropoda
Subphyla & Classes
• Subphylum Chelicerata
– Class Merostomata – (horseshoe
crabs – 6 species)
• Horseshoe shaped carapace
(exoskeleton or shell)
• Tail spine called a telson
• Respiration by book gills on
abdomen
• Five pairs of walking legs and
one pair of chelicerae (mouth
parts)
• Widely used in research over
circulation
Horseshoe Crab
HORSESHOE CRAB IMAGES
Representative Arthropoda
Subphyla & Classes
• Subphylum Chelicerata
– Class Arachnida – (five orders including spiders, ticks, scorpions ,
camel spiders and daddy long legs) – 82, 000 species
• Mostly free-living and found mainly in dry, sunny areas
• Body parts made of two tagamata (body sections), the
cephalothorax and abdomen. The cephalothorax usually bears
one pair of chelicerae, four pair of walking legs, and a pair of
pedipalps
• Most arachnids are predators and have fangs, claws, poison
glands or stingers
Representative Arthropoda
Subphyla & Classes
• Subphylum Chelicerata
– Class Arachnida
Orders of Arachnida
• Order Araneae (spiders) 40,000 species
– Body made of two tagmata: prosoma and opisthosoma; both unsegmented and joined by a narrow waist joined by a pedicel.
Anterior appendage called chelicerae hold the fangs.
Pedicel
Orders of Arachnida
• Order Araneae –
– All spiders are predators.
After a spider seizes a prey
with its pedipalps and
injects poison with its fangs,
it liquefies the tissues with a
digestive fluid and sucks the
broth. Some spiders have
teeth that crush or chew
prey mixing the venom.
Spider eating wasp
Orders of Arachnida
• Order Araneae –
– Spiders have 8 simple eyes and sensory setae which are sensitive
hairs that cover its body surface and act as triggers to signal the
location of its prey
– Spiders breathe by means of tracheal tubes or book lungs or
both
Orders of Arachnida
• Order Araneae –
– Spiders and insects have unique excretory systems of malpighian
tubules which collect urinary waste and drain into the intestine
Orders of Arachnida
• Order Araneae –
– Production of silk in silk
glands produces the webs
of spiders. The silk is
formed from a
schleroprotein which
hardens when it hits the
air. Spider silk is stronger
than steel threads of the
same diameter. They will
stretch one-fifth (1/5) of
its length before breaking
Orders of Arachnida
• Order Araneae –
– The most dangerous
spiders in the US are the
black widow which uses a
neurotoxin and the brown
recluse (fiddleback) which
uses a hemotoxin
Black
Widow
Spider
Brown
Recluse
Spider
Brown Recluse Spider Bite
Orders of Arachnida
• Order Scorpionida(Scorpions) 1400 species
– A. Scorpion tagmata are a short cephlathorax which holds all the
appendages and a long slender abdomen which ends in a stinging
apparatus.
– B. The stinger consists of a bulbous base which houses the poison and a
curved barb.that injects the poison. Venom of most species is not fatal
to humans but may be very painful, however the stings of certain species
in Africa and Mexico can be fatal.
– C. Scorpions feed mainly on insects and spiders.
– D. They have from 1 to 100 offspring
which the mother broods inside her
reproductive track until the egg hatches
and then carries the young on her back
till their first molt.
• E. Scorpions can live for up to 15 years.
•
Orders of Arachnida
Order Solpugida
(camel spiders)
a. non venomous
arachnids that shred
prey with their large
chelicerae or
pinchers
b. Range in size from
1-15 cm
– Common in
middle east , Asia
and Africa
Orders of Arachnida
• Order Opiliones (Harvest Men) – 5000 species
– Commonly known as Daddy Long-Legs
– Different than spiders, cephalothorax and abdomen are one broad
region without the narrow waisted pedicel
– Have four long spindly legs that end in claws, they can loose these
legs without ill effect and can regrow them.
– They are not venomous or harmful to humans.
– They are the only Arachnids that have a penis for sperm transfer.
– They feed as scavengers
Orders of Arachnida
• Order Acari (ticks and mites) 40,000 species identified but it is thought
that over 500,000 species exist.
– The most medically and economically important arachnid class
– Adult ticks and mites possess 4 pair of legs and the larva possess 3
pair of legs
– Chiggers are larval Trombicula mites, they feed on human dermal
tissue and cause irritation of the skin
– There are several tick species that carry serious illnesses,
ex. Ixodes carries Lyme disease
Tick
Mite
Chigger Life Cycle
And
Chigger Infestation of Human Skin
SUBPHYLUM MYRAPODA
•
•
means many footed
Respiration is by tracheal tubes and spiracles
Excretion is by Malpighian tubules
Class Chilopoda
• Class Chilopoda (centipedes) means margin-foot
– 3000 species worldwide
– These are land forms with somewhat flattened bodies
– One pair of legs per body segment
– Fast-moving carnivore that feeds on insects, earthworms, snails and
even lizards and small toads
– Poisonous claws on the first segment
paralyze prey
– May have up to as many as 177 segments
Class Diplopoda
Class Diplopoda (millipedes) means 1000 footed
a. Up to 10,000 species worldwide
b. Presence of diplosegments which is derived from
the fusion of 2 body segments and has 2 pair of
legs per segmen
c. Have 25 to 100 segments depending on the
species
d. Non-venomous but may spray an toxic or
irritating fluid from special
glands on the sides of their
bodies.
e. After millipedes copulate the
female lays eggs in a nest that
she guards carefully.
Subphylum Crustacea
(Shrimp, Lobster, Crab, Crayfish)
• Only arthropods with 2 pair of antennae
• One pair of appendages on each body segment
• All appendages are biramous (have two main branches)
Biramous appendage –
two main branches
Subphylum Crustacea
(Shrimp, Lobster, Crab, Crayfish)
Banded Coral Shrimp
Crab
Lobster
Crayfish
Subphylum Crustacea
(Shrimp, Lobster, Crab, Crayfish)
• Body sections are usually the cephalothorax and abdomen
• Dorsal covering is called the carapace
• Last part of the tail region bears the anus and is called the telson
– (Sides of the tail are called the uropods)
Subphylum Crustacea
(Shrimp, Lobster, Crab, Crayfish)
– Have gills for respiration. Special maxillary appendages called gill
rakers wave continuously to draw water over the gills.
– Most crustaceans brood eggs in chambers or sacs attached to the
abdomen or attached to abdominal appendages
– Most crustaceans have a larvae unlike the adult form and is called
the naupilus; it must undergo metamorphosis
Fairy Shrimp Naupilus
Classes of Subphylum Crustacea
• Class Branchiopoda (fairy shrimp and water fleas) – very small
– Flattened leaf-like legs function in respiration
– Mostly freshwater – swim with jerky flea-like motions
Fairy Shrimp
Water Flea
Classes of Subphylum Crustacea
•
Class Copepoda
• Most abundant organism in
aquatic ecosystems
• Some free living copepods are
intermediate hosts of
human parasites such
as tapeworms and
nematode worms.
Classes of Subphylum Crustacea
– Class Theocostraca (barnacles)
• Originally classified as molluscs because of heavy shell
which is really a highly modified carapace
• Are filter feeders and remain attached to a substrate for
their entire lives.
• Frequently foul ship bottoms and can
reduce the speed of ships by
30 to 40 %.
They also attach to wharves .
Barnacle
SUBPHYLUM CRUSTACEA
CLASS MALACOSTRACA
• Large class – accounts for 70% of crustaceans 20,000 species
– (only focus on a few of the most important Orders for study)
Class Malacostraca
• Order Isopoda – pill bugs, only truly terrestrial crustaceans
• Many have the ability to roll into a tight ball for protection
• Locally referred to as roly-polys
Pill Bugs
Class Malacostraca
• Order Amphipoda – similar to pill bugs, some marine and some
freshwater of terrestrial, commonly called sand fleas or beach hoppers
Class Malacostraca
Order Euphausiacea
( krill)
Most are bioluminescent
Travel in enormous swarms
Form the major part of the diet of
the largest animals on earth
such as the whale shark and
manta rays
Class Malacostraca
• Order Decapoda (10 legged) 18,000
species
– (Lobster, Shrimp, Crab, Crayfish)
• Most are marine; some
freshwater, a few crabs can
live on land
• First three appendages are
modified as maxillipeds –
for food handling
• One or more walking legs
are chelate
• may be very large (largest is
the Japanese Crab with a
chelae span of over 10 feet
(4 meters)
Japanese Spider Crab
Class Malacostraca
• Order Decapoda
– The head and thorax is fused
into a cephalothorax which is
covered by a carapace that
encloses gill chambers
– Most are either predators or
scavengers
– This is a very important order
both commercially and
environmentally
_ many have unusual symbiotic
relationships such as decorating
their carapaces with sponges or
sea anemones for camouoflage
Japanese Spider Crab
SUBPHYLUM HEXAPODA
HEXAPOD MEANS “SIX FOOTED”
• Terrestrial or aquatic animals with uniramous appendages.
One enormous class that is the most diverse and abundant
of all Arthropods. There are more species of insects than all
other species of animals combined
• The study of insects
is called entomology
SUBPHYLUM HEXAPODA
Class Insecta
• Class Insecta (largest class in animal kingdom - # of
species estimated @ 1 million
– Fundamental features of all insects:
• Have 3 tagmata
– Body consists of head, thorax and abdom
• Adults insets have three pairs of legs and on
two pairs of wings
• Insects are found in all environments except
marine
• Insects play a major medical and economic
and are critical to the environment
SUBPHYLUM HEXAPODA
Class Insecta
• They can feel, taste, and hear with antenna
• They usually have one pair of compound
eyes
• The thorax is divided into the prothorax,
mesothorax and metathorax , each with one
pair of walking legs
SUBPHYLUM HEXAPODA
Class Insecta
• All insects except fleas, lice and termites
have wings, most have two sets except for
true flies which have one set of wings and
one set of halteres – used for stability
SUBPHYLUM HEXAPODA
Class Insecta
• Divided into Orders on the basis of wings
and mouth part structure
• There are about 30 Orders in this class but
we will study only 14
Class Insecta
• Order Ephemeroptera
(Mayfiles)
– Adults only live one day
– Adults have no gut and do
not feed – only reproduce
– Larvae live for a year or
more underwater
– Have four membranous
wings
Mayfly
Class Insecta
• Order Odonata (dragonflies and damselflies)
– Are found near water
– Larvae are aquatic and carnivorous
– As adults, are flying predators
Dragonfly
(Notice wing structure)
Class Insecta
• Order Orthoptera (grasshoppers, crickets)
– Most are herbivorous with mouthparts adapted for chewing
– Wings are folded under leathery forewings, in some species wings
are reduced or absent in adults
– Undergo incomplete metamorphosis
Cricket
Grasshopper
Class Insecta
• Order Mantodea ( Mantis)
• Body elongated with Raptoral front legs
• Lifestyle Predatory
• May reach 10 cm in length
Class Insecta
• Order Isoptera (termites)
– Live on cellulose from wood and depend on microbes in their gut
to digest this indigestible product
– Are social insects living in damp tunnels
– Shed their tiny membranous wings @ maturity
Immature
Termite with
Wings
Adult Termite
Class Insecta
• Order Phthraptera (sucking lice and chewing lice)
–
–
–
–
All are blood-sucking ectoparasites
of mammals
Two species attach humans;
head and pubic lice (crabs)
Serious pests of birds and other
livestock
Eat bits of skin scraped from the
host
Sucking Louse
Chewing Louse
Class Insecta
• Order Thysanoptera (thrips)
– Primarily plant feeders that suck sap from leaves and flowers
– Serious pest of cultivated plants and can transmit plant diseases
Onion Thrip
Class Insecta
• Order Hemiptera (true bugs such as stinkbugs, water striders,
aphids , cicadas and bedbugs)
– Some, such as the bedbug, have piercing mouthparts to suck blood
or ingest plant sap
– Have leathery front half of wing and membranous back half
– Wings are held flat over abdomen
– Many have odorous scent glands
Stink Bug
Bedbug
Bedbug Bites
Bedbug
Class Insecta
• Order Neuroptera (lacewing)
– Weak fliers
– Lacewing larvae are
predators of aphids and are
valuable to gardeners
– Wings are lacy looking and
held roof-like over body
when at rest
Common Lacewings
Class Insecta
• Order Coleoptera (beetles)
– Fore-wings are hardened and thickened as protective covers
called elytra for the membranous hind wings
– 300,000 species found all over the world
– **Largest Order in animal kingdom **
– Beetles are herbivorous, carnivorous, predators, some eat
fungus and some are scavengers
Class Insecta
• Order Lepidoptera (butterflies and moths)
– Two pairs of membranous wings
– Wings and body are covered by scales
– Mouthparts of adults form a drinking tube that is coiled under
the head when not being used
– Caterpillars are plant-eaters that form silk cocoons in which they
transform into adults through complete metamorphosis
Moth
Butterfly
Differences in Butterflies & Moths
•Most butterflies fly during the day, and most moths fly during the night.
•A butterfly's antenna have knobs at the ends of their feelers, and the
ends of the moth's antenna is either feather like or plain.
•Most butterflies rest with their wings held up above their bodies and
most moths rest with their wings spread out flat.
•Typically butterflies have brightly colored wings and moths have dull
colored wings.
•Most butterflies have slender, hairless bodies, while most moths have a
fat abdomen and furry bodies.
•Most moths have tiny hook or bristle hooking the forewings and hind
wings together. Butterflies do not have this hook.
Class Insecta
• Order Diptera (true flies)
– This order contains house flies, fruit flies, mosquitoes and horse
flies
– Have only 1 pair of wings, the hind-wing has evolved into a club
shaped balancing organ called a haltere
– Some dipterans feed on nectar or sponge up digested food
– Many human diseases are transmitted by dipterans
Green bottle fly
Fruit
Fruit
Flies
fly
Class Insecta
• Order Siphonaptera (fleas)
–
–
–
–
Small and wingless insects
Piercing and sucking mouthparts
Can jump from one host to another
Fleas transmit a number of diseases
such as plague or tapeworms
Flea
Class Insecta
• Order Hymenoptera
• (bees, wasps, and ants)
– Two pairs of membranous wings but
wings behave as a unit
– Thorax and abdomen are separated
by a narrow waist
– Most display complex social
organization
Honey Bee
Wasp
Ant