Section 3: Phylum Porifera (Sponges)

Cellular level

No true tissues

Mostly sessile

Sponges are primarily non-motile.

Asymmetry

Most sponges exhibit no symmetry.

Filter feeding

The primary method by which most sponges obtain food.

Marine and freshwater environments

The habitats where sponges are found.

Spicules or collagen

The materials that make up sponge skeletons.

Calcium carbonate skeleton

The type of skeleton found in Calcarea sponges.

Six-rayed siliceous spicules

The skeleton characteristic of Hexactinellida sponges.

Radial symmetry

The symmetry exhibited by most Hexactinellida sponges.

Trabecular reticulum

The unique tissue organization found in Hexactinellida sponges.

Siliceous spicules (not six-rayed)

The skeleton characteristic of Demospongiae sponges.

Demospongiae

The most diverse class of sponges.

Demospongiae, due to leuconoid body plan

The class that contains the largest sponges.

Sparse or lacking skeleton

The type of skeleton found in Homoscleromorpha sponges.

Archaeocyte

Another name for amoebocyte.

Asconoid body plan

Simplest body plan; choanocytes line spongocoel; water enters through porocytes; only in Calcarea.

Syconoid body plan

Body plan with walls folded into radial canals lined with choanocytes; water enters prosopyle and exits via apopyle.

Leuconoid body plan

Most complex body plan; features many oscula and clusters of flagellated chambers; no spongocoel.

Both

Sponges can reproduce sexually and asexually.

One individual produces both male and female gametes

The definition of monoecious in sponges.

Choanocytes

The cells that produce sperm in sexual reproduction.

Archaeocytes

The cells that produce oocytes in sexual reproduction.

Asexual buds that detach and form colonies

The definition of external buds in sponges.

Dormant masses of encapsulated archaeocytes for survival in harsh conditions

The definition of internal buds (gemmules) in sponges.