Phylum Porifera Flashcards
What are the two major groups within the Amoebids?
Amoebozoa and rhizaria
List as many characteristics of the Amoebids as you can
- No cilia
- Typically only one nucleus
- Contain pseudopodia
- Flagellated ancestors
- NO sexual conjugation
Reproduces via:
gamete formation or encystment
Describe the amoebozoans: consider feeding habits, shape, environment, and other characteristics.
- Shapeless
- Pseudopodia
- Prefer moist environments
- Feeds via phagocytosis and pinocytosis
- Secrete proteinaceous or siliceous tests
- Aggregation to form giant amoeba
- Pseudopodia project through tests
What are the two major groups in Rhizaria?
Phylum foraminifera and phylum radiozoa
Briefly describe the rhizaria
- Filopodia
- Can be simple or branching and complex
List some characteristics of Phylum foraminifera
- CaCO3 tests
- Complex pseudopodia through pores
- Primarily benthic and marine
- Symbiosis with dinoflagellates (coral)
- Reticulopodia
List some characteristics of Phylum Radiozoa
- Axopodia (responsible for phagocytosis)
- Rigid endoskeleton of silica or str. sulfate
- Can form symbiosis with algae
What are the three major groupings of flagellates?
Phytoflagellates, free-living zooflagellates, and parasitic flagellates
What are the simplest metazoans?
Sponges
Describe phylum Porifera (sponges)
- No nerves, muscles, or locomotion
- Classed as a plant until 1765
- Allow for continuous water flow through flagella
- multicellular
-Asymmetrical
Define ostia
Ostia are incurrent pores
Define Spongocoel
The empty central cavity or atrium
Define osculum
Excurrent pores on the sponge
What makes up the mesohyl layer?
- Collagen
- Spongin
Collagen and spongin makes up a matrix of cells with proteinaceous material. - Spicules
What are spicules used for?
- Skeleton support; found in mesohyl and is made of calcite or silicate
What are Pinacocytes?
Cover outer surfaces of the sponge, they are 1-cell layer thick, and basilar forms glue the sponge to a substrate
Define porocytes
Porocytes are pores that allow water flow; incurrent pore = ostium. They cover the outer sponge.
Define choanocytes
Flagellated cells lining spongocoel and choanoderm; are used to capture food/ sperm. They also provide water flow.
Define sclerocytes
Sclerocytes are amoebid cells that secrete spicules
Define spongocytes
Spongocytes are amoebid cells that produce the protein spongin
Define archeocytes
Archeocytes are amoebid cells known as the transformer cell. They are undifferentiated but can produce gametes, digest, store food, and they are found in the mesohyl.
Does high complexity equal evolutionary success?
Nope
What are the three morphotypes of phylum porifera?
Asconoid, synconoid, and leuconoid
Describe asconoid morphology
- Large central cavity lined with choanocytes and spongocoel
- Pinacoderm lacks folds
- Larger forms are difficult
(Least complex morphotype)
Describe asconoid morphology water flow
Water flows via:
- Ostia
- Flagellated spongocoel
- Osculum
Describe Syconoid morphology
- Folded and pushed out pinacoderm
Two complex canals:
1) Incurrent canal
2) Radial canal
(medium complexity morphology)
Describe syconoid morphology water flow
Water flow via:
- Incurrent canal
- ostia
- flagellated radial canals
- reduced spongocoel
- osculum
Describe leuconoid morphology
- Increased folding in pinacoderm
- Incurrent canal
- Radial canal
- Several oscula
- Little to no spongocoel
(Most complex sponge morphology)
What does having increased folding in the pinacoderm mean for pumping efficiency?
Increased surface area and increased pumping efficiency
Describe leuconoid morphology water flow
Water flow via:
- Ostia
- Branching incurrent canals
- Prosopyle (specialized water flow pore)
- Flagellated chambers
- Excurrent canals
- Osculum
How does asexual reproduction occur in phylum porifera?
Fragmentation and gemmule production
Define gemmule reproduction
An unfavorable form of asexual reproduction where a mass of archeocytes is surrounded by a capsule with spincules
How does sexual reproduction occur in phylum porifera?
- Broadcasting a spawn of gametes (hermaphroditic) where choanocytes produce both egg and sperm while archeocytes exclusively produce egg.
What are the four classes of phylum Porifera? List some characteristics of each
1) Calcarea
- CaCO3 spicules
-Asconoid, synoconoid, leuconoid
2) Demospongia
- 80% of most species
- Mostly leuconoid
-spongin are silica
- Contains all freshwater
- Never contains CaCO3
3) Hexactinellida
- glass sponges
- syncytial cell layers
4) Homoscleroma
- Most lack spicules
- Pinacoderm is ciliated
