Biology of Aspatharia sinuata

Delivered bySHITTU OlalereDept. of Zoology,

University of Ilorin, Nigeria

External Shell Characteristics

Internal Shell Characteristics

Internal Shell Characteristics

Internal Shell Characteristics

The Mantle Cavity

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

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.

Section through heart and Gills

Feeding

Feeding mechanism

Anatomy of the Internal Organs of Bivalves

Anatomy of the Heart

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.

Marine forms exhibits external fertilization

Veliger larva swims for about two weeks before spat formation.

Four years to reach adulthood.

Life Cycle of Bivalves

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