AP Biology Phylum Porifera

2.  Means animal with pores
 Most simple
 5,000-10,000 species
› Most live in water
› About 150 species in fresh water
 Example: sponges (natural sponges have
many advantages – cleaning, decorations,
last longer, easier to clean, hold more water
with out dripping, some very soft, painting,
some have components used in antibiotics)
› No organs, muscles, nerves, mouth or digestive
cavity (lack mesoderm layer)
› Have specialized cells for different functions=
division of labor
› Asymmetrical or radial symmetry

3. › Outer layer AKA epidermis
› Mesenchyme – layer under epidermis, jelly-like
and holds SPICULES in place (calcium
carbonate or silica) which weave together to
form the SPONGIN (basic skeleton)(made of
protein)
 Spicules give the organism support and
protection
› Porus body – many pores throughout
(porocytes)
 Ostia – incurrent for water and whatever else
 Oscula – excurrent for water and whatever
else

4. › Filter feeders – eat primarily plankton
 Special cells call CHOANOCYTES or
COLLAR CELLS that have flagella
 Process
 1. small food particle are brought in through
the ostia
 2. collar cells capture the particles
 3. surround & engulf (like an amoeba)
 Digestion is intracellular
• * These cells also help oxygen to enter
(respiration) and waster to leave
• * Fact – a 4 inch tall sponge that is ½” in
diameter can filter up to 30 gallons of water
per day

5.  Movement – adults do NOT move, in the larva
stage some can
 Reproduction –
Asexual
› A. budding - new growth from adult
› B. regeneration
Sexual
› Eggs and sperm released in to water
› Fertilized by chance
› * Fact - Most are hermaphrodites
› After fertilization larva develops, when mature it
leaves the parents and sets down in another
place, during that fall it forms a hard case around
it AKA GEMMULE (helps to withstand freezing, lack
of oxygen, drying out, etc….)

6. Shapes
 Asconoid sponges are shaped like a simple
tube perforated by pores.
 Syconoid sponges tend to be larger than
asconoids. The synconoid body wall is thicker
and the pores that penetrate it are longer,
forming a system of simple canals.
 The third category of body organization is
leuconoid. These are the largest and most
complex sponges. These sponges are made
up of masses of tissue penetrated by
numerous canals