Invertebrates - porifera, cnideria Flashcards
porifera
the sponges
sponges are not enmatazoa
are not organized into tissues
choanocytes
flagellated collar cells, engulf bacteria and food by phagocytosis
amoebocytes
totipotent (can become any cell type)
w/in mesohyl
digest food, transport nutrients, make skeletal fibers
spicules
defensive spikes made of calcium carbonate
hermaphrodites
each individual functions as both male and female
only releases one type of gamete at a time
zygotes
flagellated, swimming larvae
cnideria
jellies, hydras, corals
radial symmetry
sensing in all directions, not really directed movements
nerve net
noncentralized, coordinates movement, senses things
single opening
both mouth and anus
Two Formed Body Plan
Polyp
Medusa
polyp
adhere to a substrate, mouth upwards
(not all polyps have a medusa stage)
medusa
free swimming, mouth down
Feeding -
predators
tentacles capture and consume
cnidocytes & nematocysts
cnidocytes
on arm tentacles, cells that sting and used to capture and defend
nematocysts
specialized organelles w/in cnidocytes that eject a stinging thread
Types of Cnidarians
Medusozoans
Anthozoans
Medusozoans
all include medusa stage + polyp stage
jellies and hydrozoans
stinging cells
anthozoans
only polyps
corals and sea anemones
corals
can be solitary or colonial
form symbioses w algae
secrete hard exoskeleton
Coral Reefs
coral move very little but secrete their skeleton and make rock-like reefs
types of reefs
fringing - on side of island
barrier - create lagoon around island
atoll - just a lagoon
Zooxanthellae
dinoflagellate/protist
symbiotic relationship w coral and provides nutrients to coral and uses CO2
requires light for photosynthesis
temperature dependent?
- become toxic when too warm
- coral dispels them
- die due to lack of nutrients
