23 Flashcards
what animals are in phylum anthropoda
jointed legged animals
what is the largest phylum
anthropoda
anthropoda habitat
marine freshwater and terrestrial
what is the most economically important phylum
anthropoda
anthropoda diet
herbivores, predators, detrivores, parasites
subphyla of anthropoda
pancrustacea
myriapoda
chelicerata
trilobita
are crustaceans hexapods and myriapods all seperate phylum
-hexapo0ds and myriapods were previously sister phylums
-molecular data suggests crustacea and hexapods part of pancrustacea
-myriapoda sister to pancrustacea
myriapoda and pancrustacea part of what clade
mandibulata
what is sister clade of mandibulata
chelicerata
what do all mandibulata have
mandibles
anthropoda body and limbs
jointed limbs and jointed exoskeleton
-lack of motile body cilia
what are exoskeleton functions
-protection and structural support
-muscle attachment points
why are anthropoda so diverse
tagmatization
how many antenae do arthropods genereally have
1
what tagmata do all anthropoda have
head 2-5 segments
myriapoda tagmata
a head and a homonomous trunk
pancrustacean tagmata
head thorax and abdomen
what are head and thorax combined as
cephalothorax
most chelicerates tagmata
cephalothorax and abdomen
what is the exoskeleton composed of
dorsal tergite, ventral sternite, and lateral pleurites
what must happen for the animal to grow
exoskeleton must be moulted
3 layers of cuticle
epicuticle
exoculticle
endoculticle
epicuticle
protine only and thin, moulted
exocuticle
chitin and protein and minerals, moulted and schlerilized
endocuticle
chitin, proteins and minerals, resorbed before moulting
what hormone controls moulting
ecdysone
what parts of anthropoda are shed
gills, lining of foregut, hindgut and tracheae
stages between moults called
instars
steps of moulting
-apolysis
-inactice moulting fluid
-protective layer
-endocuticle digested
-new undifferentiated layer of cuticle with greater surfface area, starts out wrinkled
…
-ecdysis, and animal swallows shit to help
-new cuticle expands
-new cuticle sclerotized
apolysis
epidermis separates from endocuticle
ecdysis
old exocuticle and epicuticle moulted
what are the segments of arthropod limbs called
articles
whjat is the most basal (closest to body) article called
coxa
what arises from basal articles
side branches
what are side branches that project medially called
endites
medially
tawards body
what are side branches that project laterally called
exites
biramous vs uniramous
biramous: two terminal branches
uniramous: one terminal branch
what controls limb movement in anthropoda
muscles
where do muscles attach
apodemes
what are two type4s of limbs
phyllopodous
stenopodous
phyllopodous limb
flattened
stenopodous
tubular
what limb joints do stenopodous limbs have
ball and socket hinges
intrinsic vs extrinsic articles
intrinsic: articles moved by muscles attached in previous article
extrinsic: articles moved by muscles attached in body
stops
overhangs that prevent overflexion or overextention
what cleavage do many anthropoda have
intralecithal cleavage
what is cleavage similar to anthropoda
velvet worms
coelom of anthropoda and how does it arise
reduced, haemocoel
arises via schizocoely
how do juveniles grow
addition of segments jsut anterior to terminal segment
is gas exchange a problem in anthropoda
yes becayse of thick exoskeleton
gas exchange needs thin cuticle
aquatic anthropoda respiration
limb branch gills
or book gills
terrestrial anthropoda respiration
-spiracles/ tracheae/ tracheoles
-book lungs
spiracles
openings to outside
tracheae
largetubes
tracheoiles
smaller tubes deliver oxygen to cells
anthropoda nervouse syst
ventral nerve cord
dorsal brain and circumesophageal connectives
brain of anthropoda
2-3 lobes
segmentally arranged ganglion
what are anthropoda eyes called
compound eyes
what are compound eyes composed of
ommatidia
ommatidia what is it composed of
cuticulular lens, light sensitive cells, and nerve
what is the image made of
many seperate spots of light
compound eyes and light. what can they be
apposition
superposition
superposition eyes
are dark adapted
have pigments concentrated in upper part of ommatidium allowing leakage of light to lower parts
where do superposition eyes work best
-low light
-low-resolution images produced
apposition
light-adapted
pigment that screens most of ommatidium, so light doesnt leak into others
apposition eyes work best in
bright light
high-resolution images
what eyes do chelicerates and myriapods have
ocelli
ocelli
simple eyes w single lens
jumping
spiders eyes
ocelli produce very sharp images
