CHARACTERISTICS OF SPONGES Cellular level of complexity. Adults asymmetrical or superficially radially symmetrical. Adults are sessile, and larvae are motile. Reproduction sexual and asexual. A skeleton helps maintain the structure of the sponge. IMPORTANT CELLS AND FUNCTIONS Amoebocytes secret spicules – are needle-like spikes Porocytes – are the cells in the body wall that allow water to flow through the body wall. Choanocytes – are flagellated cells that help in filter-feeding TYPES OF CANAL SYSTEMS Most sponges can be classified based on their type of canal system. Asconoid Syconoid Leuconoid ASCON This canal system is the simplest of all three. Steps of the passage of water through the canal system (Entry of water- Ostia – Spongocoel- Osculum – Outside) Sycon type This type of canal system is more complex compared to the ascon type. EX. Scypha. Steps of the passage of water through the canal system : (Entry of water-Ostia- incurrent canal - Prosopyles - Radial canals – Spongocoel- Osculum – Outside) Leucon type Most complicated and common sponges EX. Spongilla Steps of the passage of water through the canal system (Entry of water - Ostia- incurrent canal- Prosopyles -Flagellated chambers - Apopyles - excurrent canals -Osculum- Outside) PHYLUM COELENTERATA Characteristics of coelenterates The members are jellyfish, sea anemones, corals, and hydras. Habitat- both marine and freshwater. The nervous system and the circulatory system is absent. Have a mouth surrounded by tentacles, which have stinging cells called nematocysts Respiration is simple through the gaseous exchange. Sexual and asexual reproduction (Budding) Ectoderm Endoderm mesoglia THE REPRODUCTIVE STAGES Alternation of generations in Coelenterates The medusa stage reproduces sexually by the production of egg and sperm, and it gives rise to the polyp stage. The polyp stage reproduces asexually by budding and gives rise to the medusa stages in Coelenterates Echinodermata Live in shandallow coastal water oceans Exclusively marine Unsegmented body Pentamerous secondary radial symmetry Unique water vascular system Word Echinodermata meaning( spiny skin) ORGANISMS Sea star Brittle star Sand dollars Sea cucumbers First phylum(Internal skeleton) With dermal calcareous ossicles Some with spines on spicules Digestive system complete Locomotion by tube feet and arms No kidney Monoecious

1. i. PORIFERA
ii. COELONTERATA
iii. EXCHINODERMATA

2. CHARACTERISTICS OFSPONGES
 Cellular level of complexity.
 Adults asymmetrical or superficially radially symmetrical.
 Adults are sessile, and larvae are motile.
 Reproduction sexual and asexual.
 A skeleton helps maintain the structureof the sponge.

3. IMPORTANT CELLS AND
FUNCTIONS
 Amoebocytes secret spicules – are needle-like spikes
 Porocytes – are the cells in the body wall that allow water to
flow through the body wall.
 Choanocytes – are flagellated cells that help in filter-feeding

4. TYPES OFCANAL SYSTEMS
 Most sponges can be classified based on their type of canal
system.
 Asconoid
 Syconoid
 Leuconoid

5. ASCON
 This canal system is the simplest of all three.
 Steps of the passage of water through the canal system
 (Entry of water- Ostia – Spongocoel- Osculum – Outside)
Sycon type
 This type of canal system is more complex compared to the ascon type. EX.
Scypha.
 Steps of the passage of water through the canal system :
 (Entry of water-Ostia- incurrent canal - Prosopyles - Radial canals –
Spongocoel- Osculum – Outside)
Leucon type
 Most complicated and common sponges
 EX. Spongilla
 Steps of the passage of water through the canal system
 (Entry of water - Ostia- incurrent canal- Prosopyles -Flagellated chambers -
Apopyles - excurrent canals -Osculum- Outside)

6. PHYLUM COELENTERATA
Characteristics of coelenterates
 The members are jellyfish, sea anemones, corals, and hydras.
 Habitat- both marine and freshwater.
 The nervous system and the circulatory system is absent.
 Have a mouth surrounded by tentacles, which have stinging cells called nematocysts
 Respiration is simple through the gaseous exchange.
 Sexual and asexual reproduction (Budding) Ectoderm
 Endoderm
 mesoglia

7.  Alternation of generations in Coelenterates
 The medusa stage reproduces sexually by the production
of egg and sperm, and it gives rise to the polyp stage.
 The polyp stage reproduces asexually by budding and gives
rise to the medusa stages in Coelenterates
THE REPRODUCTIVE STAGES

8. Echinodermata
 Live in shandallow coastal water
oceans
 Exclusively marine
 Unsegmented body
 Pentamerous secondary radial
symmetry
 Unique water vascular system
 Word Echinodermata meaning(
spiny skin)

9. ORGANISAMS
 Sea star
 Brittle star
 Sand dollars
 Sea cucumbers

10. GENERAL CHARACTERISTICS
 First phylum(Internal skeleton)
 With dermal calcareous ossicles
 Some with spines on spicules
 Digestive system complete
 Locomotion by tube feet and arms
 No kidney
 Monoecious