Quiz 1 - Poriferans Flashcards
what are some key features of sponges
sessile
asymmetric
cell level organization
incomplete gastrolation - spongecoel
do sponges have true tissue
no, cellular level of organization
what is meant by poriferan cells are autonomous
if you disociated the cells, they can re-aggreagate and form a new sponge
- must be some cell communication going on
what is the outer layer called
pinacoderm
is the mesohyl a true tissue layer
no its an inner cellular region, but not true tissue
what are the primary layers of a sponge
pinacoderm and choanoderm
what are the defining features of the poriferans
aquiferous system
sessilt filter feeding
the aquiferous system - the small incurrent pores are called… ther excurrent pores are called… what’s the open cavity part called?
ostia - in
oscula - out
spongeocoel - cavity (not a true cavity though)
what are the four classes of sponges
hexatinellida
demospongiae
calcarea
homoscleromorpha
what is the newest class of sponges
homoscleromorpha
orginally with demo, but actually closer related to calcarea
body plans - choanocytes line the spongeocoel, no canals or chambers…
asconoid
body plans - choanocytes line the canals due to more invagination of spongeocoel
synconoid
body plans - choanocytes are in chambers, all connected together
leuconoid
what body plan are the majority of sponges?
leuconoid
where do you see the asconoid and synconoid body plan? what class?
calcarea sponges
synconoid body plans - how did they develop
spongeocoel invagination to make canal, choanos line these canals
hexatinellida, homoscleromorpha and demospongiae… what do they all have in common in terms of their body plans
all leuconoid
the skeletal system of sponges depend on what…
*the taxonomic fingerprint of the sponges
microscopic spicules + spongin
how do the microscopic spicles of sponges differ between the classes
calcarea - 3 prong spicules
homo + demo = glass spicules
hexa - 6 prong silica spicules
what is spongin
part of skeletal system
leftover skeletal parts without any spicules and without cells
collagen like protein
what class of sponges is in the deep sea, lacks spongin, doesn’t really have a canal system and lacks pinacoderm?
hextinellida
what class of sponges helped develop fibre optics
hexatinellida - 6 rayed silica glass spicules
hexatinellida lacks spongin (collagen like protein) and lacks a real canal system - what are they made of structurally?
syncytial sheets
very basal form - even choanocytes lack nuclei
what class of sponges has representatives of all three canal systems?
calcarea
what class of sponges can reach the largest sizes
demospongiae - up to 2m in size
are all demospongiae sponges in freshwater?
no, not all are freshwater species but all freshwater sponges are demospongiae
what kind of spicules to demospongiae and homoscleromorpha have?
silica spicules
how to demospongiae sponges have a mutualistic relationship with crabs
crabs will put sponges on their bodies for added protection and predator deterrent
what are the sponge cells that transform into other cell types (totipotent) called? they help make spicules and spongin
archaeocytes / amoebocytes
the contractile cells of sponges that control the size of the oscula / pore openings are call…
myocytes
*modified from pinacocytes from outer layer
what is the role of the choanocytes
pumping and feeding, in chambers/canals/inner lining, flagellated collar cells
what cells contain sponge sperm
choanocyte
what cell type make the ostia?
perocyte
what to sclerocytes do?
make specular skeleton
what has 3 pronges silica spicules that are all the same size…
homocleromorpha
what is the role of spongin
to make scaffolding of sponge body
collagen like protein
makes up the mesohyl + skeleton
helps arrange spicules
why are the archaeocytes located in the mesohyl of the sponge
aid in digestion
sponge cells to the breaking down
what class of sponges contains carnivorous sponges
demospongiae
how do carnivorous sponges gather food
tiny barbed hooks that cover the branching limbs of the sponges
have a feeding vacuole that envelops prey for digestion
why do most carnivorous sponges lack choanocytes?
because they don’t filter feed, no need to choanos
what allows sponges to reproduce asexually
totipotency allows them to bud off and make genetically identical sponges
sexual sponge reproduction - where to the oocytes (eggs) and sperm come from? i.e. what cell types make these
oocytes - archaeocytes
sperm - choanocytes
how do the larva travel
ciliated larva, find new location to settle and grow
explain how sponges asexually reproduce
itnernal buds / gemmules
- made by archaeocytes in mesohyl
- coated w spongin + spicules
the tough, spongin + spicule coated gemmules of sponges have the ability to go dormant in harsh conditions… what sponge type would the be an advantage for?
demospongiae / freshwater sponges because environment is prone to harsh changes
what is the oldest sponge fossil?
ediacaran hexatinellida - can see the 6 rayed spicules… but some speculate its a ctenophore because they also look like comb rows
where do the majority of microbial sponge symbionts reside
the mesohyl
how are the microbial sybiont relationships different in the deep sea sponges than the pelagic sponges in shallower waters
deep sea - less photosynthesis more chemosynthetic relationships
what are some of the main function of sponge symbionts
chemosythesis in deep sea photosynthesis in shallow defense nutrient cycling sponge loop
what are some examples of how microbes help sponges with nutrient cycling
help convert inorganic forms of nitrogen into a usuable form
what is the sponge loop
transferring of dissolved organic matter to a particulate organic matter (usuably via some microbialsymbiont)
what is a holobiont
mini ecosystem relationship
co-dependence on another organism
what is the difference between horizontal and vertical transmission of microbes?
horizontal - filtering
verticl - transmission through gametes, via budding
what is chemotaxis
chemical cues from sponge to call microbes
viruses are abundant in the water column of the ocean.. how do sponges protect themselves from this
virome = viruses in sponges and bacteria phages
- have a relationship with the bacteria, host + phage
- phage down regulated immune response of host
do all sponges have the same microbes? do they all come from the sea water?
no, geographically different
no, microbes found on sponges that are not in the sea water
