PHYLUM PORIFERACOMMON NAME: SPONGES

There are 900 species in this group - mostly marine .

Below are several examples.

Yellow sponge Vase

spongeTube sponge

Key Characteristics of Sponges

multicellular with few specialized cells (no mouth, tissues, or organ systems)

asymmetrical- no front/back or left/right sides

simple skeleton: Harder sponges: skeleton is

made of spiny spicules Softer sponges: skeleton is

made of spongin, a network of flexible protein fibers. harvested and used as natural

bath sponges.

Natural bath sponge

Barrel SpongeKingdom

: Animalia

Phylum: Porifera

Class:Demospongiae

Order: Haplosclerida

Family: Petrosiidae

Genus: Xestospongia

Species:X. testudinari

Essential Functions

7

Feeding

Fundamental question: How do choanocytes help sponges feed? specialized cells with flagella move a steady current of water (and food!)

through the sponge. Note: also helps bring oxygen & carry away waste

Filter feeders: sifting microscopic food particles from the water.

Respiration, Circulation, Excretion

As water moves through the body cavity, oxygen dissolved in the water diffuses into the cells of the sponge.

At the same time, waste such as carbon dioxide and ammonia diffuse into the water and are carried away.

Water flow brings oxygen and carries away wastes

Response

Very limited… no nervous system.

Many sponges protect themselves by producing toxins that make them poisonous to potential predators.

Toxic Poison Finger Sponge- note the aposematic coloration!

ReproductionSexual reproduction Hermaphrodites:

produce both egg and sperm, but at different times.

Asexual reproductionSome sponges can reproduce by a process called budding.

Movement

ONLY ABLE TO MOVE DURING THE LARVA STAGE

SESSILE AS ADULTS

EcologySPONGES… provide habitat for marine animals -

snails, sea stars and shrimp

are a food source for many organisms such as sea stars and fishes.

Mutualistic symbiosis: provide a protected place for bacteria, algae and plantlike protists to grow. These photosynthetic organisms provide food

and oxygen to the sponge.

Small fish can hide inside sponges

Threatened species: Cloud Sponge

-They are extremely fragile… bodies are composed of silica (glass)

Bottom trawling breaks their bodies- threatening the survival of the population

Threatened cloud sponge

Resources

Miller, Kenneth and Levine, Joseph. Biology. Upper Saddle River: Prentice Hall, 2004.

"Marine Mysteries - Could Solving These Mysteries Save The Oceans?" Marine Mysteries. World Wildlife Federation, n.d. Web. 11 June 2012. <http://www.marinemysteries.ca/>.

"Treasures of the Sea Exhibit." Treasures of the Sea. Delaware Technical Community College, n.d. Web. 11 June 2012. <http://www.treasuresofthesea.org/>.