February's Mystery Picture - What is it?

Email us with your answer!
(There is no prize, it's just for fun and you might get a mention on our website!)

January 2005. Mystery Picture - A Close-up of a Slime Mould, around 2cm in length.  These weird organisms behave partly like a fungus and partly like a protozoa (colony of unicellular animals).  There are two types: cellular and plasmodial.  Cellular slime moulds consist of single celled organisms which engulf their  food such as the bacteria to be found in dead wood and on damp ground.   When the food supply runs out, up to 100,000 of these single cells join together to form a slimy mass which is able to slowly move (a bit like an animal) to a new location in the search for more food.  When food is found the mass of cells develops fruiting bodies (like fungi) which produce spores that go on to produce more single cells of the slime mould, so continuing the life cycle.

Plasmodial slime moulds have an even more complex life cycle involving sexual reproduction.  They form blobs of mucus-like colonies of cells without their cell walls, called protoplasm.  This colony can spread over surfaces such as the bark of trees and the stalks of plants.

Slime moulds spread by sending out tubes called pseudopodia in a variety of directions.  When some of these tubes encounter a new food source, those which have not found a new food source 'shrink' back and the colony gradually moves to the food-rich area.

Unfortunately, no-one correctly identified January's Mystery Picture, admittedly it was quite difficult!   Several people thought that the picture showed natural sponges.   Thank you to all who had a guess including Trish A. Van Doren and Joshua Gager.