Phylum Porifera Flashcards
the basics
- Comes from earliest groups of animals
- Means pore bearing
- Sessile, passively filer feed using choanocytes to move water
- Water system, depends on water movement
- Water comes in through ostia and out through ocula
- Internal cavity = spongocoel
- Very efficient bc a sponge the size of a milk carton could filter a swimming pool in a day
- ~5-8000 species
- Most marine but around 150 in freshwater
choanocyte
- Flagellated collar cell
- Powerhouse of the sponge
- Dictates body, how effective of a feeder it is
- similar in structure to choanoflagellate protist → reason for name
canal systems
- How it lines the body dictates effectiveness
- Just how body is organized
asconoid
- Asconoid: choanocyte lines spongocoel
o Only class calcarea
o Small bc surface-volume ratio
syconoid
o Folded inner layer created canals (choanates fill side canal and then it infolds so there are more chanocytes in small area)
o Bigger sponge but not huge
leuconoid
(choanocyte lined chambers)
o Very very big (human or bigger!)
o Not really a spongocoel, just an osculum
o In all classes
what makes a sponge a sponge
- Choanocytes: water currents and feeding
- Archaocyte/ameobocyte
o Can become many things (like stem cells)
o Becomes good at growing from very small amounts
o Totipotent cell in mesohyl
o Can become cells that:
• Phagocytosize
• Make spicules
• Make sponging
• Make collagen
• Or are used for reproduction
sponge skeletons
- Many things hold together
- Collagen fibers in all sponges
- Some turn collagen into sponging
- Siliceous spicules (silica)
- Certain types of sponges have diff type of spicules
- Hold sponges together, give shape, predator deterrent bc too sharp and pointy to eat
- Calcium carbonate
- Taxonomic footprint
class calcarea
o Has calcareous spicules (made of calcium carbonate)
o Only with all 3 canal systems
o Typically relatively small
class hexactinellida
o 6-rayed silica spicules with a class latics o cells not divided by a membrane (undivided nuclei)
class homoscleromopha
Used to be with demospongiae but bc of molecular work it got its own class
o Pinactoderm have a different orientation
o Spicules not distinct (same form)
o Cellular distinctions (pinacoderm is not the same as epithelium)
class demospongiae
o 80% of sponges
o Contains the only freshwater guys
o All leuconoid
o Bath sponges
feeding
- Intracellular digestion – phagocytosis
- Cells can be inside body and a little thing to eat goes by so it engulfs it
- Bc of chemicals and spicules not many things eat sponges
carnivorous sponges
- Harp sponges, most demospongae
- No choanocytes
- Little hooks that capture prey
- Don’t know how they digest
reproduction
- Both asexual and sexual
- Sexual:
o Sperm from choanocytes → released into water and taken by another sponge
o Specialized cells (oocytes) make eggs from archaocytes - Asexual:
o Budding (fragmentation)
o Dormant gemmules in freshwater bc of the unpredictable environment (needed to protect internal buds)
