Phylum- Porifera

 Phylum- Porifera 

GENERAL CHARACTERS:

The phylum porifera meaning pore bearing animals. The term is coined from Latin –Porous –pore ferre- to bear . The body surface bears pores.

General characters.
1.    They are aquatic animals found in fresh water some are marine forms.
2.    They are diploblastic, multicellular animals
3.    The consist of outer ectoderm and inner endoderm.
4.    Between ectoderm and endoderm  gelatinous mesogloea is present.
5.    Mesogloea  contains different types of amoeboid cells.
6.    The shape of body is vas shaped or cylindrical, symmetrical or asymmetrical.
7.    The surface of body shows minute pores called ostia.
8.    Toward the free end large opening is present called osculum.
9.    The body cavity encloses large cavity called spongocoel.
10.    Canal system is well developed consists of incurrent canal, excurrent canals.
11.    Body is supported by calcareous or silicic spicules and spongin fiber.
12.    Digestion is holozoic and intracellular.
13.    Reproduction is sexual as well as asexual.
14.    Regeneration power is very high.
15.    Fertilization is internal.
16.    Cleavage is holoblastic.

Phylum porifera consists of three classes these are
1.    Class 1 - Calcaria
2.    Class 2 – Desmospongia
3.    Class 3 –Hexactinellida

SYCON

Kingdome-       Anemalia       Eukaryotic, Multi-cellular, without chloroplast        

Phylum -          Porifera           Pore bearing, cellular grade organization.

Class –             Calcaria           Exoskeleton is made up of calcium carbonate,         

Order –            Heterocoela                  Canal system is well developed.

Type –             Schypha/Sycon                      

CHARACTERS:

1. Sycon is solitary or colonial sponge found attached to rock or any solid substratum.
2. Body is made up of many cylinders attached at the base.
3. Exoskeleton is made up of calcium carbonate.
4. Each cylinder show wide opening called osculum.
5. Body surface is perforated with minute aperture called ostia.
6. Sycon encloses large cavity called as spongocoel.
7. Canal system is well developed.

HYALONEMA

Kingdome- Anemalia                     Eukaryotic, Multi-cellular, without chloroplast         

Phylum -     Porifera                      Pore bearing, cellular grade organization.

Class –        Calcaria                       Exoskeleton is made up of calcium carbonate,          

Order –       Amhidiscophora          Spicule  are ambhidisc i.e. with convex disc

Type –         Hylonema  (Glassroap)

8. Reproduction sexually as well as asexually. Asexual reproduction by budding and regeneration.  

CHARACTERS:

1. It is commonly called as glassrope sponge
2. Body is rounded or oval and radially symmetrical.
3. Five and six  rayed spicule extends from all over the body.
4. Spicules are amphidisc i.e. with convex disc.
5. Attaché to substratum by stalk like root tuft..
6. Ex-current canal opens on gastral surface.
7. Presence of gastral cone.

 

SPONGILLA

Phylum - Porifera        Pore bearing, cellular grade organization.

Class -    Demospongia           Spongin fibres or siliceous spicules present. Canal system is present.

Order -    Monaxonida            Spongin may or may not be present, spicules monaxon type.

Type -     Spongilla

CHARACTERS:

1. Spongilla also called as bath sponge .
2. Spongilla is freshwater colonial sponge found in ponds and lake.
3. It found attached to the submerged objects.
4. It is brown in colour.
5. Spongilla  show wide opening called osculum.
6. Body surface is perforated with minute aperture called ostia.
7. Body  surface shows presence of minute apertures called ostia.
8. The skeleton shows spongin fibers and spicules.  
9. Reproduction sexually as well as asexually