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