lecture 13 Flashcards
clade ecdysozoa
What are Ecdysozoa
moulting animals
moult
shed entire cuticle atleast once in life cycle
cuticle
non living covering of epidermis
what phylums are contained in Ecdysozoa
nematoda
namatomorpha
priapula
what animals are considered nematoda
nematodes
roundworms
threadworms
how many species of nematodes
27000 named species
where do nematodes reside
freshwater, marine, terrestrial
what type of digestive system do nematodes have
complete digestive system
what type of respiratory or gas exchange systems do nematodes have
no circulatory or gas exchange systems
what muscles do namatodes have
body wall muscles, exclusively longitudinal
are nematodes diverse>
no, they have veru little morphological diversity
do nematodes have coelom?
pseudocoelomates
do nematodes have brain
no, but they have circumesophogeal connectives
do nematodes have nerves?
they have 2 nerve chords
dorsal and ventral
how are signals sent in muscle cells
muscle cells send projections to the locomotory nerves
what sexes are nematoda
can have seperate sexes, or be hermaphroditic, or have a combonation of the two
how is sperm transfered in nematoda
copulation
what type of development do nematoda have
direct development
what type of cleavage do nematodes have
determinate cleavage and eutely
caenorhabditis elegens what are they known for
model nematode where every cell is known
what do free living nematodes feed on?
small organic particles
what is different about free living nematodes? why?
they have a strong pharynx
for sucking in liquides containing suspended particles
what do nematodes eat
-free living mfs feed on organic particles
-some are predators
-and many are parasitic to plants and animals, and HUMAN
what do entomopathogenic nematodes have
symbiotic bacteria
entomopathogenic nematode life cycle
once host penetrated, nematode release symbiotic bacteria. bacteria kill host with toxins, and the nematodes feed on host.
what is phylum nematomorpha
the horsehair worms
how many species in phylum nematomorpha
365 named species
what are some characteristics of phylum nematomorpha
the adults are extremely long
the cuticle is very thick
do nematomorpha have muscles
they lack circular muscles, like nematoda
does nematomorpha have coelom
they have filler material, no obvious pseudocoelum
does nematomorpha have a gut
gut highly reduced or absent in adults because they dont feed
nematomorpha larva
whatdo they look like and do
larva has spiny eversible head.
they paracitize terrestrial insect and induce the host to move to water
what is phylum priapula
penis worms
how many named species of priapula
22
where do priapula live
they burrow in marine sediment
what is the introvert of the priapula
it is a spiny eversible head used for burrowing
do priapula have coelum
yes, they have pseudoceolum
what type of development priapula
deuterostome style
what do priapula eat
they are predatory, they evert toothed pharynx
trace fossils priapula
high diversity during cambrian period
