Transcript Arthropods and Echinoderms

 What
is an arthropod?
 In
the Phylum Arthropoda there are
crabs,
spiders, and insects.
 They
have segmented bodies, tough
exoskeletons, and jointed appendages
(antennae or legs with joints) ....places
that bend
 The
evolution of Arthropods led to fewer
body segments and highly specialized
appendages used for feeding, movement,
and other stuff (functions)
 Most
living arthropods have only 2 or 3
segments (sections)
 They
have specialized appendages
(antennae, walking legs, wings,
mouthparts)
 Arthropods
can be herbivores,
carnivores, and omnivores.
 They

have an open circulatory system
They are classified based on the
number and structure of their body
segments and
appendages......especially their
mouthparts
 Most
terrestrial (land) arthropods
breathe through network of branching
tracheal tubes that extend throughout the
body.
 They
dispose of wastes that has
(contains) nitrogen using Malpighian
tubules (saclike organs)
 They
use internal fertilization
 Most
aquatic Arthropods have gills and
use external fertilization.
 Molting
is when arthropods outgrow their
exoskeleton they start molting (get rid of
exoskeleton so they can grow and make
(manufacture) a new one that is bigger.
 Crustaceans
are in the subphylum
Crustacea and include crabs, shrimp,
lobster, crayfishes, barnacles.
 Crustaceans
have 2 pairs of antennae, 2
or 3 body sections , chewing mouthparts
(mandibles)
 Crustaceans
with 3 body sections have a
head, thorax, and an abdomen
 The
thorax lies just behind the head and
houses (keeps) most of the internal
organs
 The
Crustaceans with 2 sections have a
head and thorax that are together
(fused).
 Together, the
fused section is called a
cephalothorax
 The
Chelicerates are in the subphylum
Chelicerata and include horseshoe crabs,
spiders, ticks, and scorpions.
 The
Chelicerates have many mouthparts
(chelicerae), 2 body sections, and most
have 4 pairs of walking legs
 Horseshoe
crabs are one of the oldest
living arthropods
 Arachnids
 They
are in the class Arachnidia.
include spiders, mites, ticks, and
scorpions.
 Spiders
are the largest group of
arachnids.
 Spiders
spin strong webs (by forcing
liquid silk through spinnerets.
 Uniramians
are in the subphylum
Uniramia
 They
include centipedes, millipedes, and
insects.
 They
have jaws, 1 pair of antennae, and
unbranched appendages.
 Millipedes
have 2 pairs of legs per
segment

 Millipedes
feed on dead or decaying
plant matter
 Centipedes
have a few to more than 100
pairs of legs.
 Most
of their body segments have 1 pair
of legs each (per segment).
 Centipedes
are carnivores
 Insects, (Bees, Moths, Beetles)
have a bodies
that have 3 parts (head, thorax, abdomen)
and:

 3 pairs of legs are attached to thorax
 1pair of antenna
 1 pair of compound eyes
 2 pairs of wings
 3 pairs of appendages used as mouthparts
(including pair of mandibles)
 Also
have a variety of different mouth types
 Compound
A
eyes have many lenses.
compound eye can detect minute
changes in color /movement.
 Metamorphosis
is the process of
changing shape/form.
 Metamorphosis
/ development.
happens during growth
 Incomplete
Metamorphosis results in
 immature forms of insects that look like
adults but aren’t adults.
 Nymphs
gradually acquire (get) adult
structures
 Complete
Metamorphosis is the process
of insects hatching into larvae, that look
like adults, then the larvae changing into
pupa (stage of time) as it changes to an
adult.
 Insects
are thought by many to be
destructive
 Insects
like termites (Destroy wood).
 Insects
like mosquitoes (Bite) and can
infect humans and animals with West Nile
and Malaria
 Bees
though, are actually beneficial
(pollinate crops)
 Insects
communicate though sound,
chemicals, and other types of signals
(like ants).
 Pheromones
are specific chemical
messengers that affect behavior /
development.
 Societies
are complex associations
(group) of animals that work together to
benefit all of them (not just the
individual)

 Animals
that form societies are ants,
bees, and termites.