Canal system of sycon

Introduction Habitat :-Scypha is marine, colonial, branched and sedentary sponge of cosmopolitan Commonly called as Urn-sponge. Habits:- Locomotion:-absent Feeding:-omnivorous and holozoic. Digestion is intracellular. Reproduction:- monoecious or hemaphrodite both sexual and asexual. Show cross fertilization due to protogynous Regeneration:-high restroative regeneration power

Canal system of sycon Definition :-system of interconnected canals of different types present inside the sponge body. Also called aquiferous system

Components of syconoid canal system Dermal ostia Incurrent canal Prosopyle Radial canal Apopyles Excurrent canal Spongocoel Osculum

Types of canal system Asconoid Syconoid leuconoid

Asconoid canal system Wall thin,unfolded Formed of two layer outer pinacoderm and inner choanoderm Minute opening called ostia present on wall Mesoglea weakly develop and of uniform thickness Choanocytes lines the whole of spongocoel. Spongocoel opens by osculum. Oscular fringe present on osculum

Route of water Out side water Spongocoel Out side Dermal ostia osculum

Syconoid canal system Wall much thicker and folded. Mesoglea thick may form cortex in certain area. Dermal ostia may open into radial canal or through incurrent canal Choanocytes are restricted in the radial canal only Spongocoel narrow open out by osculum

Route of water flow Outside water Radial canal Spongocoel Outside Dermal ostia Internal ostia osculum

Leuconoid canal system Wall much folded than syconoid canal system Dermal ostia openin incurrent canal either directly or through the hypodermal space Choanocytes confined in flagellated chamber, formed by evagination of radial canal Spongocoel either reduced, narrow or absent.

Significance of canal system Carries microscopic food particles for nutrition Carries oxygenated water for respiration. Carries sperms for reproduction. Carries out undigested food for egestion. Carries out nitrogenous wastes for excreation.

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