Poriferan Characteristics
- Multicellular, but lack true tissues
- Asymmetrical or radial symmetry
- Adults sessile suspension feeders
- Internal skeleton composed of spicules (calcium carbonate or silicon dioxide) or collagen fibers
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Class Desmospongia
Characteristics
- Includes majority of sponges
- Spicules composed of silicon dioxide or replaced by spongin (collagen network)
- Nearly all have leuconoid grade of construction
- Diverse marine and fresh water habitats
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Fire Sponge, Tedania ignis, Belize
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Red Sponge, probably Plocamia karykina, CA
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Class Calcarea
Characteristics
- Spicules composed of calcium carbonate
- Spicules not usually differentiated into mega- vs microscleres
- Includes species with Asconoid, Synconoid, and Leuconoid body forms
- Marine
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Scypha sp., a synconoid-type sponge; preserved specimen.
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Leucosolenia sp., an ascanoid-type sponge; stained whole mount.
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Scypha sp.; stained longitutinal section, 100x.
See also labeled photo.
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Grantia sp.; stained cross section (related to Scypha), 100x.
See also labeled photo.
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Grantia sp.; cross section showing spicules, 400x.
See also labeled photo.
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Class Hexactinellida
Characteristics
- Glass Sponges
- Spicules composed of silicon dioxide, 6-rayed; complex skeletons
- Radially symmetric
- Syconoid and leuconoid body forms
- Lacks outer pinacoderm layer
- Deep water marine
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Venus' Flower Basket, Euplectella sp., skeleton.
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