Phylum Porifera Flashcards

Terms Definitions
2 subkingdoms of multicellular animals?
Parazoa & Metazoa
Difference btw parazoa and eumetazoa?
Parazoa: no true tissues, unique embryology, cells are highly independent
Major distinguishing characteristics of Porifera (6)?
Radial or asymmetry, no true tissues or organs, no nervous system, intracellular digestion, porous body plan, spicules & spongin
Define Ostia?
Incurrent pores; water enters
Define spongocoel?
Central cavity
Define osculum?
Excurrent pores; water exits
List 4 major cell types in sponges?
Pinacocytes, porocytes, choanocytes, archeocytes
Function of pinacocytes?
External covering
Function of porocytes?
Cells lining Ostia, bring water into sponge
Function of choanocytes?
Filter/feeding cells "collar cells"
Function of archeocytes?
"Ancient cells" amoeboid; phagocytize food, differentiate, secrete spongin/spicules
3 morphological types of sponges?
Asconoid, Syconoid, Leuconoid
Characteristics of Asconoid?
Most simple, Ostia to spongocoel, choanocytes line spongocoel, small
Characteristics of Syconoid?
Folded body wall, Ostia leads to radial canals, choanocytes line canal, larger in size, small spongocoel
Characteristics of Leuconoid sponge?
Incurrent canals lead to chambers, chamber lines with choanocytes, multiple oscula, Largest, very small spongocoel
Best plan for surface to volume ratio?
Leuconoid; increased surface area to volume ratio
3 classes of sponges?
Calcarea, Hexactinellida, Demospongia
Characteristics of Calcarea?
Oldest, 3 ray spicules of calcium carbonate, spongin, Asconoid & Syconoid, dull color, 10 cm, marine
Example of Calcarea?
Characteristics of Hexactinellida?
Most advanced, 6 ray spicules of silicon dioxide, no spongin, Syconoid, dull color, 1 meter, marine
Example of Hexactinellida?
Euplectella "Venus flower basket"
Characteristics of Demospongia?
Largest group, spicules of silicon dioxide, spongin, Leuconoid, bright color, 2 meters, aqueous
Example of Demospongia?
Euspongia "bath sponge"
Discuss budding?
Asexual; new organism develops from an outgrowth on parent
Discuss gemmule formation?
Asexual; internal buds produced in response to hostile environment
Discuss fragmentation?
Asexual; organism is split into fragments which in turn develop into new individuals
Define symbiosis?
2 or more organisms living together in a close, intimate environment
Define host?
Larger partner that may benefit, be harmed, or unaffected
Define symbiont?
"Jatzia Dax"; smaller partner, always benefits
Define mutualism?
Host and symbiont benefit
Define commensalism?
Host is unaffected & symbiont benefits
Define parasitism?
Host is harmed & symbiont benefits
Example of mutualism?
Sponge provides home for algae, algae provides nutrients to sponge
Example of commensalism?
Sponge crab uses sponge for camouflage & sponge is unaffected
Example of parasitism?
Cliona bores hole in oyster, makes oyster sick
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