Transcript Dr. P`s Arthropods Notes

Athropods
“arthros” “pod”
“jointed” “foot”
Reigners and rulers of the world
 make up over three quarters of
the animal kingdom
Exoskeleton
 chitinous exoskeleton (a cuticle
secreted by underlying epidermis
that contains chitin) chitin is a
polysacchride also found in the
cell walls of fungi
 the exoskeleton serves as an
armor to protect the soft body of
the insect, as well as to aid in
mobility
 this outside skeleton must be
shed periodically as the athropod
grow the shedding is called
“ecdysis”
Paired Jointed Appendages
 Jointed appendanges
 well developed sense organs
Metamorphosis
 growth accompanied by
Incomplete Metamorphosis
ecdysis (molting) of the
exoskeleton, can become
33% larger than before the
shed
 Can grow by complete or
incomplete metamorphosis
Complete Metamorphosis
Open Circulatory System
 open circulatory system that contains the blood
(hemolymph)
Reproduction
 sexes are separate
(dioecious)
 parthenogenesis occurs in
some species (such as
bees, wasps and termites)
Crustaceans
 two pairs of antennae
 pair of mandibles,
 pair of compound eyes (usually on
stalks)
 two pair of maxillae on their heads,
followed by a pair of appendages
on each body segment The
appendages are primitively
branched (biramous), and although
this condition is modified in many
species, adults always have at least
some biramous appendages.
 Crustaceans respire via gills.
Arachnids
 4 pairs of walking legs
 “pedipalps” or “foot
feelers”
 feeding appendages
called chelicerae
 mostly predators and
parasites
Diplopods
 2 pairs of legs per
segment
 Round
 superficially
segmented body
 herbivore/scavenger
 secretes acid at
posterior end
Chilopods
 1 pair of legs per
segment
 Flat
 segmented body
 Has posterior poison
gland and anterior
jaws
 carnivores
Merostomata
 large shield that covers the
cephalothorax.
 compound eyes are reduced.
 second pair of appendages, the
pedipalps, resemble walking legs.
 They have a long, spike-like
appendage called a telson that
projects from the rear of their
bodies.
 Respiration is via book gills.
Entomology--> the study of Insects
 Insects are the most
numerous form of animal
life on the planet. Close to
80% of all animal species
humans have described are
insects. There are over
300,000 known species of
beetles -- just one type of
insect
 Body Plan
head (antennae, compound
eyes, feeding appendages)
thorax (wings, 6 legs)
abdomen (ovipositor)
Insect Classification
 Odonata (dragonflies and damselflies)
 Orthoptera (grasshoppers, crickets, katydids)
 Isoptera (termites)
 Hemiptera (true bugs,cicadas, aphids, scale insects)
 Dictyoptera (roaches, mantids)
 Coleoptera (beetles)
 Lepidoptera (butterflies and moths)
 Diptera (flies)
 Siphonaptera (fleas)
 Hymenoptera (ants, bees, wasps)
Harmful Insects
 Pests, vectors of pathogens, crop eaters, sting, bite
Beneficial Insects
 Pollination, honey, silk, food (entomophagy), biological
control, designer genes
References
 The Wonderful World of Insects :
http://www.earthlife.net/insects/six01.html
 University of Kentucky “Bug Food”
http://www.uky.edu/Agriculture/Entomology/ythfacts/bugfo
od/bugfood.htm
 MiniBeast Museum:
http://members.aol.com/YESedu/mainmenu.html
 Arthropoda Lesson: www.kent.wednet.edu/.../sci_class/
chap14/arthropod.html