Type study

1. Phylum Porifera
“Sponges”
Kingdom: Animalia
Phylum: Porifera
Classes: Hexactinellida
Demospongia
Calcarea
By
Dr. Priti D.Diwan
AssistantProfessor
Department of Zoology
J.D.Patil Sangludkar Mahavidyalay Daryapur.

2. Phylum Porifera
 Pronounced (po-rif'-er-a)
 The name means
“bearing pores”
• 5,000 living species
• Most primitive of all
animals

3. Phylum Porifera
 Sponges are sessile, meaning they have a
stationary, inactive lifestyle can move up
to 4 mm per day
 Because they are sessile, they are highly
dependent on ocean currents to bring
food to them and eliminate waste
products.
 Embryos are free-swimming.

4. Major Characteristics:
 They have no organs or true tissues.
 Digestion, respiration, and excretion all
occur by simple diffusion directly into and
out of the cells.
 No nervous system.
 Most sponges are asymmetrical.
Occasionally radial

5. Major Characteristics:
 Their bodies are made up of thousands of
cells mixed together in a gel-like mixture,
supported by small skeletal structures
called spicules.

6. Major Characteristics:
• Feed by filtering water through their outer
walls and pumping it out of body
• Flow of water is uni-directional
 Sponges are made up of a system of tiny
pores and canals that make up a intricate
filter feeding system.

7. Structure/General Anatomy:
• Opening at top called
the osculum
• Gelatinous interior
called the mesohyl
• The interior cavity
called the
spongocoel
OSCULUM - opening
MESOHYL
SPONGOCOEL

8. Sponge Skeletons
 Thin strands of collagen are found
throughout the bodies of sponges.
 The class of Demospongiae produces a
form of collagen known as spongin.

9. Sponge Skeleton
 Spicules on the left
 Spongin on the right

10. Spicules:

11. Structure / Anatomy:

13. Structure / Anatomy:
• No tissues or organs
• Each type of sponge
cell is responsible for
a specific function
• The outer surface is
covered by tiny
openings called ostia

14. Cellular Structure of Sponges
 The inner material that makes up the main body (a
type of connective tissue) of a sponge consists of a
loose gel-like mixture called Mesohyl.
 Porocytes make up the ostia that allow the
passage of water into the sponge.

15.  The epithelial cells of sponges are called
Pinacocytes. These cells play a role in trapping
food particles.

16.  Amoebocytes are cells in the mesohyl that perform
a variety of functions. The primary functions are
digestion (archaeocytes) and production of spicules
and collagen.

17. • The spongocoel is lined with flagellated
cells called choanocytes or collar cells.
• The flagella beat to cause a current –
drawing water in through the ostia
• The collar traps food particles

18. Cellular Structure of a Sponge

19. Structure / Anatomy:

20. Feeding:
• Flow of water through the
sponge allows for
feeding, waste removal,
and the intake of oxygen
• Sponges filter bacteria as
a food source
 Some sponges filter as
much as 1500 liters/day
(that is equivalent to
about 400 gallons/day).
Moving Water/Current = Low
Pressure
Water pumped in through the walls

21. Sponge Digestion

22. Digestive:
• Filter feeders
• NO GVC – food
is digested
intracellularly
• Collar cells engulf
and digest food
vacuoles
• Use amoeboid
cells to distribute
nutrients

23. Circulatory:
• Amoeboid Cells in
the wall transport
food and
nutrients

24. Excretory:
• All wastes are
purged through
the main pore
called the
osculum

25. Respiratory
• Various cells take in oxygen through
diffusion

26. Sponge Sexual Reproduction
 Most sponges are monoecious. Meaning a
single sponge can have both male and female sex
cells.
 Sperm cells develop from choanocytes. Egg cells
can develop from choanocytes in some species
and from archaeocytes in others.
 After fertilization, the a free-swimming flagellated
larva called a parenchymula breaks off from the
adult sponge and are carried away by ocean
currents.

27. Sponge Asexual Reproduction
 fragmentation and by external budding.
 Fragmentation occurs when a fragment is broken off
from the main body of the sponge.
 Budding occurs when a small sponge grows off of the
adult sponge. Eventually these can break off and
regenerate.

28. Sponge Asexual Reproduction
 Gemmules are internal buds that usually remain
dormant and contain archaeocytes.
 Gemmules are usually formed during unfavorable
conditions
 After the unfavorable conditions pass, the
archaeocytes can then be released - regenerate into
a new adult sponge.

29. Parenchymula and Gemmules
 Gemmules on
the left
 Parenchymula
on the right.

30. Sponge Ecology
 Adults are always attached to other
objects. (rocks, corals, submerged objects
etc.)
 Many other organisms such as crab and
fish live symbiotically in or on sponges.
 Some sponges live on other organisms
like mollusk shells and corals.

31. Class Calcarea
 Spicules made of
calcium carbonate
(calcite and
limestone)
 All three types of
canals represented
(asconoid, syconoid,
and leuconoid).
 All marine
Example (Clathrina)

32. Class Hexactinellida
 Six-rayed spicules
made of silica
(same substance
as glass)
 Body often
cylindrical and
funnel shaped
 Syconoid or
leuconoid
 All Marine
Example, Venus Flower
Basket (Euplectella)

33. Class Demospongiae
 Skeleton made of
silica spicules that
are not six-rayed, or
a skeleton made of
spongin, or both.
 Leuconoid type canal
systems only.
 One family
freshwater, all others
are marine.
Very diverse group of
sponges