Phylum porifera
variable shapes, asymmetrical/radial
Osculum
large opening, exit of water
Ostia
entrance of water, pores
Holdfast
root-like structure used by sponges to attach to substrate
Mesohyl
- middle layer - gelatinous - non-cellular matrix
Choanocytes
cells to acquire food
Crystalline spicules
- calcareous (CaCO3 ), siliceous (SiO2 ) - hard needle-like structures, skeletal elements
Monoactin, Triactin, Hexactine
1 rayed, 3 rayed, 6 rayed crystalline spicules
Spongin fibers
flexible fibers made of protein (a modified type of collagen protein)
Collencytes and lophocytes
secretes collagen
Spongocytes
secretes spongin fibers
Archaeocytes
amoeboid cells (amoebocytes) - totipotent cells (can differentiate to different types), do many functions (facilitating digestion & feeding)
Sclerocytes
secretes spicules
Pinacocytes
- cells forming the pinacoderm (= epidermis), outer covering - thin, flat cells (= epithelial) - may phagocytize large food particles
Porocytes
tubular cells forming the pores of asconoid sponges
Choanocytes
flagellated collar cells (distinguishing characteristic) that generate water current
Asconoid
Shortest water route, simplesrt
ostia, spongocoel, osculum
succession of asconoid
incurrent canal, ostia, radial canal, spongocoel, osculum
Syconoid succession
Leuconoid
most complex - many flagellated chambers
Incurrent canal, flagellated chamber, excurrent canal, oscula
Succession of Leuconoid
Budding
asexual reproduction of poriferans
Calcarea
brittle sponge, calcareous monoaxon spicules, 3 canal system
Demospongiae
bath sponge, siliceous spicules (not 6 rayed), some have spongin fibers, LEUCONOID CANAL SYSTEM
Venus flower basket, Euplactella sp.
with male & female shrimps locked inside
Hexactinellida
glass sponge, 6 rayed spicules, Leuconoid system