Commercial Bath Sponge (Spongia officinalis)


Taxonomy:Kingdom: AnimaliaPhylum: PoriferaClass: DemospongiaeOrder: DictyoceratidaFamily: SpongiidaeGenus: SpongiaSpecies: S. officinalis

Physical Appearance:
This sponge is dark grey or purplish when alive. When dry they can either be yellow or brown. They tend to be round, with a 35 cm diameter but can grow up to 50 cm or more. Osculum are found in the top middle of the sponge and are lined with flagella.

These sponges can only thrive in warm water such as in the Mediterranean Sea, particularly the Eastern half, and in the Bahamas and Florida. They can be found at depths of 1 meter to 40 meters, but usually they do not exceed that.

S. officinalis is a hermaphrodite; each one has both ova and sperm. When ripe, their sperm escape the body through vents and float around the sea until they are sucked into the pores of another sponge by a water current. There, the sperm fertilizes an ovum and the embryo begins to rapidly divide. Newly formed flagella beat together to break through the capsule and to escape through the pores into the sea where the organism is a free-swimming larvae for about 24 hours before it sinks into the sea bed. They can also reproduce asexually by means of budding.

With the aid of flagella, the Bath Sponge brings currents of water in through it's many pores. While passing through chambers, water is driven towards the surface and expelled while the food particles and oxygen are used by the sponge. The water leaves through the osculum bearing waste products of digestion and respiration.