Phylum Porifera

Phylum Porifera
The Sponges
1
Phylum Porifera
Phylum Porifera Overview
z
Most primitive of the multicellular animals
–
z
Sponges
–
–
2
There is some debate if sponges are complex
colonial protozans and not metazoans.
Over 7,000 species, approximately 40 species that occur in
local waters
2% of all sponges are freshwater, none are terrestrial
Phylum Porifera
Phylum Porifera Overview
3
z
Sponges occur in shallow water habitats and
vary widely in size (up to 1m. high) and shape
– Unlike most metazoans they lack:
z
All sponges are sessile filter feeders
Phylum Porifera
Sponge Diversity
Erect Rope
Sponge
Black-ball sponge
Yellow Tube
Sponge
4
Phylum Porifera
Porifera Anatomy
5
z
Spongocoel
z
Ostia
z
Oscules
Phylum Porifera
Collar Cells
z
Choanocytes
6
Choanocytes: (collar cells) act
as a pump to bring water into
the sponge
Phylum Porifera
Sponge Support
z
Collagen is found
between the inner canals
and chambers
–
z
Ameboid cells located in
the mesohyl, have
different roles
–
–
7
Mesohyl
Archeocytes
Sclerocytes
Phylum Porifera
Sponge Support
8
Phylum Porifera
Spicules
z
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
Sponge Types
Porifera Reproduction
z
z
z
Asexual budding
Regeneration: can regenerate from broken
pieces
Sexual
–
11
Usually hermaphroditic with male and female cells
scattered throughout the connective tissue.
Phylum Porifera
Porifera Larvae
z
Neighboring sponges
are fertilized by
sperm entering
through the ostia
–
12
Ciliated mouth less
larvae
(parenchymella) is
released.
Parenchymella
Phylum Porifera
Porifera Classification
z
Phylum Porifera
–
–
–
–
14
Class Calcarea
Class Demospongiae
Class Hexactinellida
Sclerospongiae is no
longer considered a
class
Phylum Porifera
Class Calcarea
z
z
z
15
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
Phylum Porifera
Class Demospongiae (Most sponges)
z
z
Have spicules made of silicon
dioxide (SiO2) or spongin or a
combination of both
Most sponges belong to this
class (90%)
–
z
z
16
Nearly all are leuconoid body
type
Mostly found on the
continental shelf
Spongia spp. (Bath sponge)
Phylum Porifera
Class Hexactinellida (Glass
sponges)
z
z
z
z
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