A. Kingdoms based on degree or grade of organization
1. protozoan = cellular grade
2. metazoans = tissue grade
3. parazoans (including Porifera) = inbetween -> superaggregate of cells
B. Physiology & anatomy => cell types
1. choanocytes - (cells with flagellum and collar) line atrium or paragaster
2. amoebocytes - mobile cells = messengers - intracellular digestion
3. archeocytes - totipotent (cells with large nucleus capable of forming other
cells as needed).
4. sclerocytes - cells that secrete skeletal elements
5. pinacocytes and porocytes - flattened cells which cover outer surface &
doughnut shaped cells which surround ostia - can close when noxious substances
are detected.
C. Physiology & Anatomy => architecture
- levels of organization (3 types)
1. ascon grade
2. sycon grade
3. leucon grade
D. Nutrition
-active suspension feeders => efficient pumpers
- bacteria size and smaller (1-10 microns) and DOM
-some with symbiotic cyanobacteria
E. Skeleton
-skeletonized => important as fossils
- CaCO3 and SiO2 used in skeletal elements -> spicules
- other support structures = spongin -> collagen fibers
** spicules often the only thing preserved
- spicule morph.
- # of axes (axons), # of rays (actines)
-> monaxon, tetraxon, triaxon - hexactinal, polyaxon hexactinal, etc.
- also mention megascleres, microscleres, and desma
- dense calcareous skeleton = stroms. and other sclerosponges
F. Taxonomy - 5 important class and 1 group of spongiomorphs
1. C. Demospongia
2. C. Calcarea
3. C. Hexactinellida
4. C. Sclerospongia
5. C. Stromatoporata
6. P. Archaeocyatha