1. Biology of Aspatharia sinuata
Delivered by
SHITTU Olalere
Dept. of Zoology,
University of Ilorin, Nigeria

2. External Shell Characteristics

3. Internal Shell Characteristics

4. Internal Shell Characteristics

5. Internal Shell Characteristics

6. The Mantle Cavity
The posterior edges of the mantle folds are modified to form dorsal excurrent and ventral incurrent openings.

7. Gills
The mantle and gills of bivalves are involved in gaseous exchange.
The gills are modified for filter feeding, they originated from the primitive ctenidia by elongation of the filaments on both sides of the central axis.
The end of the filaments folds backward to make the ctenidia filament assume a slender W shape.

8. Section through heart and Gills

9. Feeding
Feeding mechanism

10. Anatomy of the Internal Organs of Bivalves

11. Anatomy of the Heart

12. Reproduction and Development
The glochidia larvae seeks, attach to fins and gills of fishes where they encyst.
Fishes serve as agent of dispersal.
Encysted glochidia larvae undergo metamorphosis into adults which escape from the cyst and sink to the bottom of muds.

13. Life Cycle of Bivalves Marine forms exhibits external fertilization
Veliger larva swims for about two weeks before spat formation.
Four years to reach adulthood.

14. End of presentation Thanks for Listening