22 panarthropod- lobopod phyla Flashcards
what is panarthropoda part of
ecdysozoa
what does being in ecdysozoa mean
mooult entire non living cuticle and also lack primary larva
what are the extant phyla of panarthropoda
tardigrada
onychophora
arthropoda
what percent of animals does panarthropoda make up
more than 80
how do panarthropoda differ from other ecdysozoans
segmented bodies w pairs of libs
what characterizes limbs of panarthropoda
they can be jointed or they can be lobopods
lobopods
fleshy unjointed outpocketings
what was envisioned as transitional taxon that joined annelids and arthropods
Onychophora
is Onychophora actually the transitional taxon b/w annelids and arthropods?
no, just close relationship b/w arthropoda and Onychophora
tardigrada
water bears
tardigrada how many spp
1200
tardigrada habitat
terrestrial in wet soil and moss
what describes tardigrada head
no antennae
what describes tardigrada body and limbs
four body segments w paired lobopod limbs that have distinc claws
how does tardigrada move
slow stepping motion
what systems do tardigrada lack
circ and excretory system
tardigrada coelom
small eucoelom that surrounds gonals
majority of euceolem haemocoel
what muscles do tardigrada have
lack circular muscles but have muscles bands that attach to cuticle
tardigrada nervous system
dorsal brain w circumoesophageal connectives and pair of ventral nerve chords
what are tardigrada eyespots
non image forming inside the brain
tardigrada feeding
feed on bacteria, algae, decaying plant matter, small invertebrates via sucking
what characterizes tardigrada pharynxq
muscular b/c sucking
tardigrada sexes
parthenogenic with few hermaphroditic
4 ways sperm is transfered in tardigrada w diff sexes
1) into females genital opening
2) hypodermic insemination- pierces cuticle and deposit sperm
3) male stimulates female to oviposit, then smears sperm over eggs
4)male copulates with moulted cuticle and female oviposits in old cuticle
what type of fertil;ization tardigrada
external or internal
development tardigrada
direct
tardigrada howq do they grow
eutely
tardigrada eggs
highly resistant
why is lifespan for tardigrada so long
they are masters of cryptobiosis
cryptobiosis
state where mf alive but no metabolism
what is a form of cryoptobiosis used by tardigrada
anhydrobiosis
what is anhydrobiosis
where all water is eventually lost from animal
what are tardigrada resistant to
outerspace, manny environmental stresses and absence of water
phylum onychophora
velvet worms
onychophora spp
200
onychophora habitat
only entirely terrestrial phylum of animals
head of onychophora
one pair of antennae
body of onychophora
homonomous segment with 1 pair of lobopod limbs tipped w claws
what types of muscles onychophora
circular, longitudinal, dorso ventral, also have metanephridisa
coelom of onychophora
restricted to pockets around gonalds and haemocoel
circ system onychophora
open but they have heart
onychophora nervous system
dorsal brain and paired ventral nerve chords
eyes onychophora
have very small eyes
how do onychophora exchange gasses
tracheal system with spiracles or stigmata
stigmata or spiracles
opening in side of body
what do stigmata lead to in tracheal system
tracheae(large tubes)
onychophora feeding
predators
how do onychophora capture food
glue glands that spray glue
development onychophora
What are young worm born w
direct
young worms born w full num howsegments
how is copulation done
hypodermic insemination
different types of reproduction female onychophora
oviparity
ovoviviparity
viviparity
oviparity
lay eggs outside body
ovoviviparity
eggs retained in mother until hatch or right before hatch
viviparity
no egg but young develop inside mommy
onychophora cleavage
neither spiral or radial
have intralecithal cleavage
what happens in viviparous spp
yolkless egg attaches to wall and nourishes via placental connection
