sponges and stingers Flashcards
invertebrate animals represent what percent of known animals
95%
how many of the 35 phyla of animals are invertebrate
34
first clade parazoa
very simple form of animals, parazoa= beside the animals
contain the porifera (sea sponges)
cellular level of organization
what does porifera mean
pore-bearers aka sponges
what level of organization do parazoa (ie porifera) have, what does this mean
cellular level of organization, lack true tissues
what is the general porifera body plan
loose federation of cells in gelatinous matrix
do porifera reproduce sexually or asexually
both
do porifera move
no, they are sessile, but they do have motile larvae stage
explain their digestive system , include how they are related to choanoflagellates
no true digestive system, do have a spongoceol; central cavity in which water passes through lined w feeding cells called chanocytes (v similar to choanoflagellates)
what is the porifera veterinary significance
they allowed drug discovery due to their many symbionts living among them
2nd clade eumetazoa means and what does it include
means true animal, ie has tissue level of organization
includes radiata and bilateria
what level of organization do eumetazoa have (ie radiata and bilateria)
tissue level of organization
how are the eumetazoa clades: radiata and bilateria sepearted
body symmetry
radiata have radial symmetry (if you cut form oral to aboral in any direction will be symmetrical)
bilateria: bilateral symmetry (only one plane of symmetry)
in the radiata family, what are cnidarians
“nettle animals” , includes jellyfish, corals, sea anemones, etc
difference between cnidocysts and nematocysts
cnidocysts are the stinging cells themselves and nematocysts are the coil/ stinger that comes out
explain the cnidarian germ layers, how many and what are they
they are diploblastic meaning 2 germ layers, ectoderm (epidermis) and endoderm (gastrodermis)
also have gut: gastrovascular cavity
explain polyp vs medusa cnidarians
polyp are attached ex coral
medusa float ex jellyfish
explain the cnidarian gut
they have a gastrovascular cavity for feeding, respiration and waste elimination
simple sac surrounded by tentacles
cnidarians are predators, they are the only group where all species are _____
venemous
do cnidarians have a brain
no, they have no head or muscle tissue, but they do have nerve net and contractile filaments
what is the cnidarian “weapon”
cnidocytes are the (stinging cells) that line tentacles, entrap prey and drag into mouth
nematocyst: coil/ stinger that comes out the end of cnidocytes
describe a mutualistic relationship with cnidarians
anemone fish and anemone
fish live and protected by anemone, also provide anemone w nutrients and chase away predators
why was the cnidarian “hydra” an important model
used to study development and regeneration, describes asexual reproduction, showed eyeless animals can respond to light, discovered vital staining
4 clades of cnidarians
1) hydrozoa : polyp dominant
2) syphozoa: jelly fish, medusa dominant
3) cubozoa: box jellyfish , cube shaped medusa
4) anthozoa: corals and anemones, sessile polyps
box jellyfish characteristics
ambush predators, small and fast, highly venomous w neurotoxin, lethal to humans, nematocysts fire on contact w skin, treatment is vinegar to disable nematocyst
irukandji syndrome
type of box jellyfish, sting mild at first but then very severe, vomiting, sweating, headache, agitation, high heart rate, high blood pressure
evidence that animals are related to choanoflagellates
choanocytes within sponges
choanocytes: similar to choanoflagellates, feeding cells, by beating their flagella they make a current and draw water in through the porocytes (the opening of the epidermis)
