2. Phylum Porifera Overview
Most
–
There is some debate if sponges are complex
colonial protozans and not metazoans.
Sponges
–
–
2
primitive of the multicellular animals
Over 7,000 species, approximately 40 species that occur in
local waters
2% of all sponges are freshwater, none are terrestrial
Phylum Porifera
3. Phylum Porifera Overview
Sponges
occur in shallow water habitats and
vary widely in size (up to 1m. high) and shape
– Unlike most metazoans they lack:
All
3
sponges are sessile filter feeders
Phylum Porifera
7. Sponge Support
Collagen
is found
between the inner canals
and chambers
–
Mesohyl
Ameboid
cells located in
the mesohyl, have
different roles
–
–
7
Archeocytes
Sclerocytes
Phylum Porifera
9. Spicules
Collagen
is stiffened
by adding microscopic
mineral accretions or
additional protein
fibers (spongin) or
both.
–
9
Spicules: skeleton
structures, made of
calcium carbonate
(CaCO3) or silicon
dioxide (SiO2).
Spicules
Phylum Porifera
11. Porifera Reproduction
Asexual
budding
Regeneration: can regenerate from broken
pieces
Sexual
–
11
Usually hermaphroditic with male and female cells
scattered throughout the connective tissue.
Phylum Porifera
12. Porifera Larvae
Neighboring
sponges
are fertilized by
sperm entering
through the ostia
–
12
Ciliated mouth less
larvae
(parenchymella) is
released.
Parenchymella
Phylum Porifera
15. Class Calcarea
Have
spicules made of
calcium carbonate
Mostly small in size (<15
cm.), and form irregular
masses
Never contain spongin,
restricted to shallow water,
and strictly marine
15
Phylum Porifera
16. Class Demospongiae (Most sponges)
Have spicules made of silicon
dioxide (SiO2) or spongin or a
combination of both
Most sponges belong to this
class (90%)
–
16
Nearly all are leuconoid body
type
Mostly found on the
continental shelf
Spongia spp. (Bath sponge)
Phylum Porifera
17. Class Hexactinellida (Glass
sponges)
17
Spicules are made of silica
Usually found in deep water on soft substrates in the
tropics 200-1,000m.
Spicules are six pointed and have a lattice-like
structure
Cup, vase or urn shape
Euplectella (Deep sea Glass sponge)
Phylum Porifera