10,000+species - all aquatic; 99% marine Invertebrates (no backbone) Simplest multicellular animals No true tissues or organs Asymmetrical No definite shape or form 10,000+species - all aquatic; 99% marine

Benthic Live on bottom of sea Sessile Live attached to substrate

Skeleton Prevents collapse of animal; forms lattice to suspend cells Spongin - protein Spicules - silica

Filter Chamber (Atrium) Covered w/pores called osculum Large excurrent pore (can have 1 or more) Ostia Tiny, incurrent pores

Myocytes Porocytes Regulate opening of osculum Regulate opening of ostia

Collar Cells Line inside of filter chamber

Create water currents to trap food Bring in Oxygen Remove wastes

SPONGE STRUCTURE

Filter Feeders Organic particles & plankton

Water enters through ostia. Water is pumped into the filter chamber. Collar cells trap food particles with flagella. Amebocytes take food to other cells within the sponge. Water leaves through the osculum.

Asexual Sexual Branches or buds break off & grow into separate sponges - “budding” Sexual Sponges produce both male & female gametes to produce planktonic larva

Encrusting Sponge Free-Standing Sponge Form thin brightly colored growths or patches on rocks or dead coral Free-Standing Sponge Subtidal habitats Tubular Sponge Barrel Sponge

Pecten Sponge Boring Sponge Found on shells of scallops Mutually beneficial relationships Boring Sponge Burrows into the shells of oysters and other mollusks Responsible for some coral reef destruction

Many sea turtles eat sponges

Hermit crab shells covered with sponges make great camoflage