Who lives in a pineapple under the sea?

SPONGEBOB SQUARE PANTS!

Well it is indeed true that Spongebob lives under the sea, sadly, he's just a made up character. But there are sponges that live in sea and no, they do not live in pineapples. Believe it or not, sponges are animals. If you were to look at them at the microscopic level, they're made up of 5 types of cell. Now I could bore you guys with all the technical mumbo-jumbo but I'll spare you guys the torture. The picture below shows it all.

Now don't be afraid of the foreign names you see here. As promised, there are only 5 cell types present in the sponge, namely

1. Pinacocyte: Cells that form the surface that faces the seawater outside
2. Porocyte: Cells that line the pores on the body
3. Choanocyte (collar cells): Cells that face the interior of the sponge. These cells posses a tail or flagella that beats around thus generating a water current to suck in the water through the pores and absorb the food particles
4. Archeocyte: These are amoeba like cells that are found in the interior and they move around the sponge transporting the food. They can also change to the other cell types if any of them are damaged or die
5. Sclerocytes: Cells that produce glass-like spines (spicule) that poke out of the sponge's body. These spines are used to protect the sponge from other animals. These spines also break easily so DON'T GO AROUND TOUCHING THEM WITH BARE HANDS! 

Absorbent and yellow and porous is he....

SPONGEBOB SQUARE PANTS

Yes, like the cartoon counterpart, real life sponges are porous and somewhat absorbent (I'll come to this later) though they come in a variety of colours aside from yellow. First lets look at why they are porous

The picture above is a slightly zoomed out view of the earlier picture. As you can see, the sponge's body is riddled with pores and that's how water and food substances enter the sponge. When the food is in the central cavity, it is taken in by the collar cell. This mode of feeding is called filter feeding. They don't have a mouth nor an anus. All they have are holes from which water enters the body and a large hole (at the top) where water leaves. The basic principle of the sponge resembles to the one above though the larger the sponge gets, the more central cavity it has. But regardless what, the basic design principle is the same as above.

When it comes to colours, they can range from being dull to the colourful. The few pictures (taken from my Facebook) below says it all

 @ Semakau

 @ Semakau

 In the photo above, the green tubes are the sponge

@Changi

@Sisters 

@ Changi

You may wonder why they are colourful. There's a reason for that. Let's take a step back from sponges and consider the following animals. What to the following animals have in common - Bees, Hornets and Poison Dart Frogs have in common?

If you say these animals are colourful, you're on the right track. These animals have bright colours to tell other animals not to muck around with them or you'll get it. In the wild, bright colours can be a form of defence even if it does not hide them. It tells other animals that they are poisonous and that you are going into a world of pain and suffering if you muck around with them. Similarly, for sponges (SOME sponges), they do employ some form of poison, one way or another, as a form of defence in addition to the spicules that they have. By doing so, it is hoped that predators stay away from them. Despite that, there are some animals that still eat sponges and they include some of your sea slugs. If you're wondering what sea slugs are, you've got to wait for it.

So enough of the sponge's biology. How about its uses to us humans?! Like its namesake, it IS ACTUALLY used as a bath sponge, usually Spongia officinalis. Of course the spicules of S. officinalis have been removed prior to using it. Aside from that, they're piquing the interest of biomedical researchers. John Faulkner from Scripps Institute of Oceanography commented that organisms that uses chemical for defence are of great interest. In another article, it was suggested that sponges may hold the key to fight malaria and in that article as well, it was commented that Japanese scientist are investigating the use of compounds extracted from sponges to fight breast, colon and urinary cancer. 

Thus this marks the end of the blog's first official post, on sponges. Before I go off, there's a summary of the post - 

1. Sponges are animals and they are made up of 5 types of cells. Each having their own specific function
2. The body of the sponge is lined with pores that allow water and food substances to enter and they feed via filter feeding
3. Sponges can be dull looking or be very colourful. They use the colours to tell other animals that they can be poisonous. In addition to poison, they also have spicules to protect themselves

In the next post, I'll be talking about one of the more beautiful animals of the sea. Despite being beautiful, they can pack a nasty sting...

Ah ha ha ha ha ha ha hargh wh...arire harrrigh

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Mentioned articles -
http://www.sciencedaily.com/releases/2010/06/100628124601.htm

http://www.smithsonianmag.com/science-nature/sponge-abstract.html

Spongebob lyrics - 

http://members.outpost10f.com/~lindax/spongebob/spongebob%20lyrics/spongebob%20squarepants%20theme.html

Sponge diagrams - 

http://www.ucmp.berkeley.edu/porifera/pororg.html

http://runningstrong-biologylibrary.blogspot.com/2010/05/sponges.html

All other information comes from my personal lecture notes and concepts that I know and understand