Ch 7 Notes - Porifera

INVERTEBRATES (animals without a backbone)

• found in the Kingdom Animalia

• 97% of all animal species

PHYLUM PORIFERA (pore bearers)

• sponges

• considered plants until 1765

• simplest multicellular animals

• cellular organization

• no true tissues, organs, movable parts, nor appendages

PHYLUM PORIFERA (pore bearers)

• mostly marine (~9000 species)

• adults are sessile filter feeders

• sessile - attached to substrate

• diversity of shapes, sizes, colors, habitats (found at low tide to 3.5 miles deep)

PORIFERA SKELETON

• asymmetrical

• 2 skeleton compositions: spicules or spongin

• spicules – made of silica (glass) or calcium and offer protection

• spongin – protein based flexible fibers; used as commercial sponges (bath sponges)

PORIFERA SKELETON

spongin

PORIFERA CELLS

• choanocytes (collar cells) – cells used to filter nutrients and move water through the sponge by beating the flagella; mucus-like substance traps nutrients; primary feeding cells of sponges

PORIFERA CELLS

• amebocytes (wandering cells) – secrete spongin and spicules; movable cells that transport and store food particles; used for repair; look like a amoeba

• pinacocytes (epidermis) – thin flattened cells that cover the sponge

PORIFERA WATER FLOW

• water enters in through the tiny pores (ostium) into the central cavity of the sponge (spongocoel) which is lined with choanocytes and leaves through the large opening on top of the sponge (osculum)

PORIFERA WATER FLOW

PORIFERA ORGANIZATION AND MORPHOLOGY

• morphologically, the bodies of sponges exhibit three distinct types based on the organization of their internal canal systems

1) Asconoid

2) Syconoid

3) Leuconoid

PORIFERA ORGANIZATION AND MORPHOLOGY

1) Asconoid – simplest type; shaped like a tube or vase with a single osculum

PORIFERA ORGANIZATION AND MORPHOLOGY

2) Syconoid – larger type with series of canals

PORIFERA ORGANIZATION AND MORPHOLOGY

3) Leuconoid – most complex and most common; numerous canals that lead to chambers

PORIFERA CLASSIFICATION

• 1) Class Demonspongiae – leuconoid form only; bath sponge - spongin gives the sponge its softness and absorbency

Pione vastifica- boring sponge

Haliclona- electric blue sponge

PORIFERA CLASSIFICATION

• 2) Class Calcarea – asconoid, syconoid, leuconoid form; most primitive group

ex: Scypha

PORIFERA CLASSIFICATION

• 3) Class Hexactinellida – leuconoid form only; glass sponge

ex: Euplectella – Venus’s flower basket