Phylum porifera

Introduction
Porifera (po-rif -er-a) (L. porus,
pore, fera, bearing)
 Most primitive of all animals
Among the approximately
15,000 sponge species are
mostly marine; a few exist in
brackish water, and some 150
species live in freshwater
 Sessile; Draws food and water
into its body
Figure 1. Some growth habits and forms of
sponges.

Characteristics
 Multicellular
Body with pores (ostia) where water, canals, and
chambers that form a unique system of water
currents on which sponges depend for food and
oxygen
Radial symmetry or none
No organs or true tissues; digestion intracellular
Excretion and respiration by diffusion

 Has choanocytes, flagellated “collar” cells
which help pump water in and out of the sponge
Figure 2. Sponge choanocytes have a collar of microvilli surrounding
a flagellum. Beating of the fl agellum draws water through the collar
(blue arrows) where food is trapped on microvilli (red arrows).

Figure 3. Food trapping by sponge cells. A, Cutaway section of canals
showing cellular structure and direction of water flow. B, Two
choanocytes and C, structure of the collar. Small red arrows indicate
movement of food particles.

Reactions to stimuli apparently local and
independent in cellular sponges;
 Nervous system probably absent
Asexual reproduction by buds or gemmules
Sexual reproduction by eggs and sperm; free-
swimming flagellated larvae in most
Characteristics

3 Types of Canal Systems
Asconoid- simplest
type among canal systems
the choanocytes lie in a large
chamber called the
spongocoel

 Syconoid-
choanocytes lie in
canals

 Leuconoid-
considered the major plan
for sponges, for it permits
greater size and more
efficient water circulation.

Body wall with two layers of loosely arranged cells and a
mesenchyme in between
 Body has an endoskeleton made up of spicules which can be
calcareous, siliceous and spongin.
Spongin
Siliceous
Calcareous

Class Calcarea
 (cal-care-a) (L. calcis, lime) (Calcispongiae).
Have spicules of calcium carbonate that often form
a fringe around the osculum (main water outlet);
spicules needle-shaped or three or four rayed
 all three types of canal systems (asconoid,
syconoid, leuconoid) represented
ALL marine.
Examples: Scypha, Leucosolenia, Clathrina.
Calcareous Sponges

Scypha
(Syconoid sponge)
Marine; Usually found in shallow
water
 Lives in fine detritus material and a
variety of planktonic organisms in
water
Solitary sponge that may live singly
or form clusters by budding
 Vase-shaped typically 1-3cm long
with a fringe of straight spicules around
the osculum

The soft body wall consists of 3 layers:
 thin flat cells which comprise the outer
epidermis, the pinacocytes;
 inner lining of choanocytes;
 gelatinous mesohyl which bear undiffrentiated
amoeboid cells, amoebocytes

Figure 4. Development of calcareous syconoid sponge,
Scypha

Leucosolenia
(Orange Pipe Sponge)
 small asconoid sponge
grows in branching
colonies
 usually arising from a
network of horizontal,
stolon like tubes

Clathrina
(Yellow Network Sponge)
 Has similar
characteristics with
Leucosolenia but only
differ with a kind of tube
it has, an intertwined
tube.

Class hexactinellida
Have six-rayed, siliceous spicules extending at right
angles from a central point
 spicules often united to form network
 body often cylindrical or funnel-shaped
 flagellated chambers in simple syconoid or leuconoid
arrangement
habitat mostly deep water; all marine.
Example: Euplectella.
Glass Sponges

Euplectella
(Venus Flower Basket)
They range from 7.5 cm to more
than 1.3 m in length.
 Distinguishing feature: skeleton
of six-rayed siliceous spicules
bounded together into a network
of glass-like structure.
 Tissues are syncytial network of
fused amoeboid cells called a
trabecular reticulum.

Class demospongea
Common Sponges
Contains 95 % of living sponge species including most large
sponges
 Have siliceous spicules that are not six-rayed
 Spicules may be bound by spongin or maybe absent
 All members of the class are leuconoid and all marine except
for members of freshwater family Spongillidae
Examples: Carterispongia, Spongia.

Carterispongia
(Elephant’s Ear Sponge)
Shape like an expanded
vase
 Its main body consists of a
broad leathery plate
 Its skeleton is made up of
only spongin and no spicules
 It has numerous ostia in its
surface and root spicules for
attachment to host

Spongia
(Bath Sponge)
Size frequently over 10 cm
in diameter.
 Globular-massive, quite
variable in shape.
 Oscules few in number, on
the upper side, up to 1 cm in
diameter.
 Consistency spongy-
elastic, compressible, supple.

Figure 4. Development of common
sponge, Demospongea

references
Hickman, Cleveland Jr. P., et al. 2008 Integrated Principles of
Zoology 14th ed. New York, USA. Mc-Graw Hill
Companies, Inc.

Submitted by:
Cacal, Brigitte Margaux
Collera, Princess
Faraon, Patricia Marie Francesca
Lustado, John Marion
Macanas, Clarissa
(Group Rhinella marina)

Phylum porifera

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Phylum porifera