Introduction to Sponges Porifera Porifera Porebearing Over 4

Introduction to Sponges

Porifera • Porifera – “Pore-bearing” – Over 4, 000 species – Mostly marine

Classification • Kingdom Animalia – Plant-like in appearance – Lack some typical animal characteristics • Distinct tissues • Dead end phylum – Nothing evolved from the Porifera

Classification • Organized into three classes – Based on skeleton structure differences • Calcareous sponges • Glass sponges • Encrusting sponges

Calcareous Sponges • Classification – Class Calcarea • Size – Small, 4 inches or smaller • Location – Shallow waters

Calcareous Sponges • Structure – Skeletons made of spicules • “little spikes” • Made of calcium carbonate (lime)

Calcareous Sponges • Two types – Leucosolenia • Simple (asconoid) canal system

– Scypha • Advanced (syconoid) canal system

Canal System Function • Simple canal system – Water enters internal cavity (spongoceol) through pore cells in the body wall • Pore cell openings – incurrent openings (ostia) • Cells of the spongoceol absorb nutrients and oxygen – Water exits through excurrent opening (osculum)

• Advanced canal system – Folded body walls • Increases surface area – Greater absorption of nutrients and oxygen

Glass Sponges • Classification – Class Hexactinellida • Size – Larger, vase-shaped • Location – Deep, tropical waters

• Structure – Skeleton made of crystalline silicon dioxide • Geometric pattern • Formed by six-pointed spicules • Possesses advanced canal system

Encrusting Sponges • Classification – Demospongiae (Demo – “people”) • Used as bath sponges • Size – Large • Location – Gulf of Mexico, Caribbean, Mediterranean Sea

Encrusting Sponges • Structure – Skeleton can be made of: • Elastic (spongin) fibers – Makes them “spongy” • Silicon dioxide • Combination of both

– Possess a complex (leuconoid) canal system • Commercial use – Collected by divers • Allowed to die/decompose in water – Spongy skeleton remains and is cleaned to be sold