University:
Brigham Young University
Course:
BIO 130 | Biology
Academic year:

2023
Views:

476

Pages:

4
Author:

SpaceSerenade

& Give elaborate account of canal system in Porifera and give their importance (20 M) A- Poriferans possess water circulatory system called as camal system or aquiferrous system. There are 3 types of camal systems on the basis of arrangement and complessity of internal Channels. 1- Ascon type- COURSE of WATER Dermal Ostia Incurrrent canal Prosopyle outside osculum Spongxoel Apopyle Radial Canal • It is more complere then Ascon type. It is derived from the asconoid type by the horizontal folding of walls. • In its developmental Stage It shows asconoid type of canal system. Body wall contain two types of canals Radial Incurrent →It is flagellated (hived by Choanocytes) →Lined by Pinacocytes It leads into radial canal through Prosopyles. →Radial canal leads to spongocoel through apopyles. • It has retained its radial symmetry. ex-scypha COURSE Of WATER Dermal ostia Incurrent Camerl Prosopyles, flagellated Chambers Apopyle outside osculum Excurrent comal • Due to further folding of the body wall of sycon, leucon type is developed. • Loss of radial symmetry due to complexity of canal. Flagellated chambers present, spongocoll reduced. Ex current canal is developed to todue to reduced spongocoel. ex- Spongilla Types of Leucon canal system -Eurypylous- FLAMELLATED CHAMBER PROSOPYLE APOPYLE EXCURRENT CANAL • Flagellated Cheruber communi. -cate directly by broad apopyle with excurrent Canal ex-Plakina COURSE Of WATER Dermal ostia Incurrent Camerl Prosopyles, flagellated Chambers Apopyle outside osculum Excurrent comal • Due to further folding of the body wall of sycon, leucon type is developed. • Loss of radial symmetry due to complexity of canal. Flagellated chambers present, spongocoll reduced. Ex current canal is developed to todue to reduced spongocoel. ex- Spongilla Types of Leucon canal system -Eurypylous- FLAMELLATED CHAMBER PROSOPYLE APOPYLE EXCURRENT CANAL • Flagellated Cheruber communi. -cate directly by broad apopyle with excurrent Canal ex-Plakina