Phylum - Porifera
Phylum Porifera
Natural history- Sponges belonging to phylum Porifera (L.porus, pores+ ferre,to bear) are sessile organisms with a low degree of individuality and cellular organisation.sponges appear like plants being sessile and attached to rocks,shells and other solid objects. Most sponges are marine distributed from Arctic to tropical seas, living from the low tide line to depths of 6 kilometres.one family (spongillidae) is distributed in fresh water. Many sponges are drab coloured and others are brilliantly red, orange, yellow, violet, black and blue.The sponges have commercial importance being used in bathroom or in automobiles .
Diagnostic characters-
1) Cellular grade of organisations.
2) Body bears several pores and hence the name Porifera.
3)Presence of canal system.
4) skeleton of calcareous or siliceous or horny spongin fibres.
5) commonly known as sponges.
6) asexual reproduction by gemmules and sexual reproduction by sperm and ova.
Classification-
Class 1 Calcaria
ex.- Leucosolenia, sycon etc.
Class 2 Hexactinellida
ex - Euplectella, pheronema etc.
Class 3 Demospongia
ex.- Euspongia, chondrilla etc.
Natural history- Sponges belonging to phylum Porifera (L.porus, pores+ ferre,to bear) are sessile organisms with a low degree of individuality and cellular organisation.sponges appear like plants being sessile and attached to rocks,shells and other solid objects. Most sponges are marine distributed from Arctic to tropical seas, living from the low tide line to depths of 6 kilometres.one family (spongillidae) is distributed in fresh water. Many sponges are drab coloured and others are brilliantly red, orange, yellow, violet, black and blue.The sponges have commercial importance being used in bathroom or in automobiles .
Diagnostic characters-
1) Cellular grade of organisations.
2) Body bears several pores and hence the name Porifera.
3)Presence of canal system.
4) skeleton of calcareous or siliceous or horny spongin fibres.
5) commonly known as sponges.
6) asexual reproduction by gemmules and sexual reproduction by sperm and ova.
Classification-
Class 1 Calcaria
ex.- Leucosolenia, sycon etc.
Class 2 Hexactinellida
ex - Euplectella, pheronema etc.
Class 3 Demospongia
ex.- Euspongia, chondrilla etc.
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