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Phylum Porifera!
= aka, the Sponges! collective = sleeze of Sponges!
Characteristics!
- Parazoa! multicellular!
lacking true tissues!
tissue = organizational level !
! between cell/organism!
! same origin!
! same function!
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Characteristics!
- no layered embryos!
Characteristics!
-  size range : 2mm -2 m!
- mostly marine, some
freshwater!
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Characteristics!
-  asymmetrical!
-  colorful!
Phylum Porifera!
- 5,000 described species!
- among the oldest known animal fossils!
530 million!
years ago!
!
extinct!
!
reef builders!
570 million!
years ago!
!
China!
- molecularly most similar to
Eumetazoa, but!
= Parazoa, so placed
with Placozoa!
Parazoa
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Body Plan!
-  no tissues but cell aggregations!
Interior!
Spongocoel, atrium!
!
!
A = mesohyl!
B = spongocoel !
with osculum!
C = choanoderm!
D = pinacoderm!
E = ostia!
Choanoderm!
epithelioid!
flagellated!
Mesohyl!
connective!
Pinacoderm!
Epithelioid!
flattened!
-  What are the cells called??????!
Asconoid!
Aquiferous System!
Syconoid!
Choanoderm!
Mesohyl!
Leuconoid!
Pinacoderm!
increased surface area, complexity
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Mesohyl: Skeletal Elements!
Spicules!
Calcium carbonate!
Silica!
!
Spongin fibers!
Collagenous material!
Mesohyl: Specialized Cellular Elements!
Lophocyte!Lophocyte!
Spongin!
!
Porocyte!
contractile!
Porocyte! !
Archaeocyte!
nutrition/reprod.!
Archaeocyte!!
Sclerocyte! Sclerocyte!
skeletal!
= Amoebocyte!
=> totipotent!
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Nutrition/ Gas Exchange!
filter feeders = water
currents!
endo/exocytosis!
amoebocyte transport!
waste = ammonia!
Sponges are considered to be
threatened due to sedimentation and
habitat destruction!
!
WHY?!
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Reproduction!
-  asexual budding, fragmentation, !
reaggregation!
-  hermaphrodites!
1.  free spawning!
2.  sperm release => migratory choanocyte => ovum => => development
in female => parenchymula/amphiblastula !
=> settlement!
!
Gemmules!
Overwintering bodies!
!
Archaeocytes = totipotent,
enclosed in spicules!
!
What type of sponges are
partial to having these
structures? Why?!
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Classification!
Class Calcarea!
calcium carbonate, all bodytypes, marine, small!
!
Class Hexactinellida!
silica, 6-pronged!
no pinacoderm but syncytium!
!
Class Demospongiae!
silica, not 6-pronged, spongin!
leuconoid!
!
Class Sclerospongiae!
hardened, carbonate, aragonite, !
calcite!
!
Class Homoscleromorpha!
Encrusting, vast, small class!
Sponge Fun Facts!
- thought to be plants until
1765!
- chemical defenses!
= novel cancer treatments!
!
- filter all the water in the
Caribbean each day!
- break of a piece = new
sponge !
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