24 Flashcards
tagmata consisted of
head
thorax
pygidium
Trilobita
all extinct
Trilobita spp
25,000 all extinct
when were Trilobita present
Cambrian
wiped out in
end-Permian extinction event
Trilobita body plan
3 lobed body
1 pair antennae
1 pair compound eyes
what type of limbs
biramous
coxal endites of trilobita
spiny
what did the mouthpart of trilobita occupy
length of underbody
limbs varied in morphology, showing
most trilobites were detrivorous or predatory mfs
Crustaceans
non hexapod pancrustacea
Crustaceans spp
70000
Crustaceans habitat
mostly marine, many freshwater, some terrestrial
what phylum includes heaviest land invertebrate
Crustaceans
Crustaceans head
5 pairs of appendages
covered by a shield
compound eyes of Crustaceans
stalked (mobile) or sessile (flat on head)
what does the head-shield extend backwards as
carapace
feeding appendages
maxillipeds
walking legs
pereopods
sexes of crustaceans
separate sexes
reproduce sexually
exceptions sexes of crustaceans
hermaphroditic barnacles
cyclically parthenogenetic cladocerans
sexual reproduction
direct transfer of sperm
no free-spawning
modified limbs for
transferring sperm
gonopods
female crustaceans do what with eggs
frequently brood
their eggs
cleavage
intralecithal, spiral or radial
unique larval stage Crustaceans
nauplius
nauplius characteristics
three pairs of appendages
naupliar eye
Crustaceans egg characteristics
very yolky eggs
where is naupliar stage
passed inside
the eggshell
what kind of development
direct development
groups with free-living nauplii undergo what?
several other larval stages
Remipedia
taxa of Crustaceans
sister to the Hexapoda
tagmata Remipedia
head
and trunk
segmentation Remipedia
homonomous segments
Branchiopoda
taxa of custaceans
cyclic parthenogens
what type of limbs Branchiopoda
phyllopodous
limbs function Branchiopoda
swimming, filter-feeding and/or gas-exchange
what is highly variable in Branchiopoda
extent of carapace highly variable
Branchiopoda feeding
mostly filter-feeders
Branchiopoda habitat
almost all are freshwater
Malacostraca taxa of Crustaceans
Hoplocarida
Diplopoda
Isopods
Amphipoda
Thecostraca
what class is important food for humans
Malacostraca
carapace malacostraca
covers part or all of the thorax
eyes Malacostraca
stalked or sessile eyes
Hoplocarida
part of Malacostraca
mantis shrimp
class with most complex eyes of any arthropod
hoplocarida
whats used for prey capture and defense Hoplocarida
spearing or clubbing or snapping thoracic limbs
strike is powerful
Hoplocarida where do they live
burrows- because small carapase
Decapoda
part of Malacostraca
how many pereopods decapoda
5 pairs of pereopods
carapace Decapoda
carapace that encloses
leg bases and gills in a branchial
chamber
Decapoda one or more pairs of pereopods are
claws evolved from normal walking
legs
claws of Decapoda can be either
chelate or subchelate
which apodeme is larger in fully chelate claw
larger and more musculated
closer apodeme
abdomen in true’ crabs
greatly reduced
Isopoda and Amphipoda characteristics
sessile eyes
lack a carapace
-fully terrestrial
isopods vs Amphipoda
isopods dorso- ventrally flattened
amphipods: laterally flattened
-more variable leg morphology
isopods and amphipods diversity
What are they
ecologically very diverse
-parasites of inverts
parasitic species isopods and amphipods
-some completely lack
appendages
-have sac-like bodies
terrestrial isopods
spiracle-trachea system
Thecostraca Subclass Cirripedia
barnacles
Cirripedia habitat
marine
Cirripedia diet
sessile filter-feeders
some parasites
filter-feeding Cirripedia
attached to
a substrate and enclosed in calcareous plates
what were Cirripedia thought to be at first
molluscs until their larvae were
discovered
do free living Cirripedia have stalks?
stalked or
unstalked
Cirripedia sexes
hermaphroditic
very
long penises
how does wave strength influence length of the feeding appendages
high wave force = short appendages
parasitic barnacles
invade the bodies of other
crustaceans
