Sponges

Haliclona cf. baeri (commonly known as pink sponge)

Scientific classification
Kingdom:	Animalia
Subkingdom:	Parazoa
Phylum: Class: Order: Family: Genus: Species:	"Porifera"Grant in Todd, 1836 Demospongiae Haplosclerida Chalinidae Haliclona H. cf. baeri

Neopetrosia sp. (commonly known as blue sponge)

Scientific classification
Kingdom:	Animalia
Subkingdom:	Parazoa
Phylum: Class: Order: Family: Genus: Species:	"Porifera"Grant in Todd, 1836 Demospongiae Haplosclerida Petrosiidae Neopetrosia N. sp. "blue"

Phylum Porifera (commonly known as Sponges)

Scientific classification
Kingdom:	Animalia
Subkingdom:	Parazoa
Phylum*:	"Porifera" Grant in Todd, 1836

Where seen?
Sponges are commonly seen on almost all our shores. They grow on all kinds of hard surfaces, from boulders, jetty pilings to coral rubble and even other animals. While many are large and colourful, others may be small, found under stones and other hiding places and thus overlooked.

What are sponges?
Often mistaken for plants, sponges are actually animals, albeit very simple animals. In fact, scientists did not even consider animals until about 100 years ago! Sponges belong to Phylum Porifera which includes about 8,000 known species.

Features:
A sponge is a simple animal made up of a few types of cells. These cells are largely independent of one another and only loosely held together. These cells do not form tissues or organs, so a sponge does not have a mouth, digestive system or circulatory system. A sponge is NOT a colony, in the way that a hard coral is a colony of individual animals.

Riddled with canals:
Sponges have a unique body plan based on a system of fine, branching canals. The sponge generates a flow of water through these canals and traps microscopic particles from this water flow

How it works:
Inside the sponge, tiny branching canals lead to chambers. Lining these chambers are cells, each with a single beating hair. The beating of these hairs generates a current through the sponge. Water is sucked in through tiny holes on the surface of the sponge. 'Porifera' means 'pore-bearing'.

These tiny holes lead to the branching canals. As the canals narrow, microscopic organic particles, bacteria and plankton in the water are captured and engulfed by the cells of the sponge. Oxygen is also absorbed. The water is then expelled out of larger holes, together with any wastes.

In this way, a sponge can filter water many times its body volume in a short time. In general, a sponge can pump water equal to its body volume once every 5 seconds!

A sponge constantly remoulds and finetunes its structure to ensure efficient filter feeding. A sponge can control the flow of water through it, and even stop it altogether (e.g., when the water is too silty).


Credit: http://www.wildsingapore.com/wildfacts/porifera/porifera.htm