PoriferaSponges

Cassie Huang Cyrus Sutaria

Shared & Unique CharacteristicsNo definite symmetry.Simplest animals- Multicellular body, few tissues, no

organs.No true body cavity.All are sessile. Reproduce sexually or asexually.Has no nervous system. Lives in aquatic environments, mostly marine. Cellular digestionAll are filter feeders. Skeleton composed of spongin and spicules.Able to repair damages to their bodies.

Sponges are sessile (non-moving) metazoans (multi-celled organisms)Sponges are multicellular and their cells are

organized to be beneficial to each otherThey lack true tissues, or groups of cells that

act as a funtional unit and are separated from other tissues by membranous

They do contain different types of cells

Classes of Porifera CalcareaHexactinellidaDemospongiae

They are split based on the type of spicules they have.

Class Calcarea They have spicules composed of calcium carbonate that

form rays and circles as they come out.They have simple shapes: either purse, vase, or cylinder

shaped.First appeared during the Lower Cambrian Period.Like the Hexatinellida and the Demospongia, they were

most diverse during the Cretaceous. Most surfaces are pastel colored, tan, or black.There are over 100 genuses of calcareous spongesThey have the greatest diversity in the tropics.Mostly found in shallow waters.

Class HexactinellidaGlass SpongesCharacterized by their six pointed siliceous

spicules.They are very uncommon and found at great

depths.Most of these animals are cupped shaped with

sturdy internal skeletons and fused spicules.They were the first sponges developed and the

earliest known Hexactinellidas are from the earliest Cambrian or late Neoproterozoic

Electric recievers on the spicules that can conduct electricity.

Scientific Name Staurocalyptus sp

Class DemospongiaeLargest, commonest and most widely distributed

group with a skeleton made of siliceous spicules.They are members of the Leucon grade, which

means that they have many canals inside their body and their shape can change throughout the day to take in more water.

They are sometimes brightly coloured. They are the only group that has freshwater

sponges.When they decompose, their spicules can easily

dissolve

Scientific Name Chalinula nematifera

SclerospongiaeSclerosponges were first proposed as a

class of porifera, but then Vacelet found out that sclerosponges occurred in different classes of porifera. ( which means they are not a closely related group)

They have a soft body with a skeleton constructed from calcium carbonate, argonite or calcite.

They are similar to coral reefs, which is why they are also named coralline sponges.

Basic Structure• Porocytes-Water enters the sponge through

porocytes• Spongocoel-Water goes from the porocytes into

the spongocoel. The spogocoel is the central cavity of the sponge where digestion takes place.

• Choanocytes-Have beating flagella which move water through the sponge. These are the “feeding” cells. Food is engulfed and digested or transferred to amoebocytes.

• Amoebocytes-Transport nutrients to other cells of the sponge. Produce materials for spicules.

• Spicules-Skeletal support structures• Osculum-Large opening on top of the sponge

where water and waste is expelled.

Basic Structure (continued)

Basic Structure (continued)Symmetry: NoneCephalization:NoneSegmentation:NoneEvolutionary “inventions”:

Multicellular, but not yet real tissue

Structure of Sponges Helps with FunctionThe whole structure of a sponge is built

around the flow of water through the sponge.There are pores to intake water and an

osculum to expel the water

Interesting Facts! YAY!• Inside a sponge, there are no organs. Special cells carry out all the

processes.

• When sponges are strained through a piece of cloth, they come back together into a new shape on the other side of the cloth.

• If part of a sponge breaks off, then it becomes an entirely new sponge.

• Near Florida and in other areas, sponges live on the backs of hermit crabs and act as a type of shell.

• Chemicals from sponges are being used to find a cure for cancer and other diseases!

• Within a sponge, it is possible to find 16,000 other animals!

• In the Caribbean Sea, sponges can filter all of the water in one day.

• The largest sponge ever measured was about 10 feet wide. It was a Monoraphus sponge.

Spongy TermsChoanocyte: also known as collar cells. Flagellated

cells that line up the internal chambers.Atrium: where water and food particles flow intoOsculum: excretory structure in a spongeSpicules: skeletal structure that provides structural

supportSpongin: collagen protein that forms the fibrous

skeleton.Parenchymello: larval form of DemospongiaeGemmules: internal buds found in freshwater sponges

The End