Phylum Porifera

Cheewarat Printrakoon

Phylum Porifera• Sponges (pore

bearers)

= Sponges are made up of a system of tiny pores and canals that make up a intricate filter feeding system.

• Adult sessile.

Phylum Porifera• Multicellular, body

traditionally considered a loose aggregation of cells.

• Structurally simple

-only cellular grade of construction (x-cytes)

• No true tissues or organs

• No symmetry (asymmetry)

Phylum Porifera

• Most distinguishing - collar cell

(filter feeding)

Phylum Porifera-Internal skeletons

Spicules (CaCO3 / SiO2) Spongin (Protein mesh/fibers)

• Bath sponge

Phylum Porifera-Internal skeletons

Some have a combination of siliceous spicules and spongin.

Cannel system – 3 categories of body form type.

Asconoid type• sponges have the

simplest type of organization.

• Small and tube shaped, water enters the sponge through dermal pores and flows into the atrium

• Choanocyte flagella create the current to expel it through a single osculum

Sycettusa thompsoni

Leucosolenida (Order) >

2. Syconoid type

asconoid pattern

Simple syconoid

Complex syconoid

• radial canal/ chamber

• choanocyte canal/chamber

• Flagellated canal/chamber

• Incurrent canal

• Apopyle

• Spongocoel

Syconoid type• sponges appear to be

larger versions

(with more infoldings)

of asconoids

• having just a single osculum.

• However, the body wall is generally thicker and more complex with incurrent canals rather than simple pores.

• In some of these sponges water enters through a canal lined by many cells.

-simple syconoid

-complex syconoid

Leuconoid type• sponges are the most

complex in design in that not all the chambers are flagellated.

• Water flowing in through incurrent canals is selectively pumped through those chambers which are, and expelled via one of a series of oscula.

• This body plan provides more circulation to deliver more oxygen and nutrients per area in large sponges.

• sponges are the best adapted to increase sponge size.

Reproduction–Asexual & SexualAsexual reproduction = Break, regenerate

• External budding • Internal budding = gemmulation

gemmule

Sexual reproduction• Broadcast sperm

• Internal fertilization

• Planktonic larvae

Class Calcarea- CaCO3 spicule

• Typically, calcareous sponges are small, measuring less than 10 cm (3.9 in) in height, and drab in colour.

• Calcareous sponges vary from radially symmetrical vase-shaped body types to colonies made up of a meshwork of thin tubes, or irregular massive forms.

• Found in 3 body types(Asconoid : Leucosolenia ,

Syconoid: Sycon, Leuconoid)

Leucosolenia

Class Hexactinellida- glass sponge

• SiO2 spicules(6 branches)

• dried out skeleton often looks like dried out glass

• present as individuals and range from 10-30 cm

• Deep sea, cold habitat

Class Demospongiae• Large spongin, • mesh protein fiber• Well known as

“bath sponge”

• All are “leuconoidtype”canal system.

• SiO2 spicules, 95% of all sponges.

• All freshwater are in this class.

Porifera laboratory

1.Skeletal composition.2. Class Calcarea- Leucosolenia, animals in slides- Scypha or Grantia, syconoid body type3. Class Hexactinellida (Hyalospongiae)- Euplectella sp.- Venus’ flower basket4. Class Demospongiae- Commercial sponge - Sponge gemmules