Weekend Sponging – Unsung Sponges

To “sponge” off somebody is frowned upon. A lazy layabout comes to mind – someone who is not willing to pull their weight and has to rely on the work or gains of other people. I think this is a very unfair use of the word “sponge”. As sessile and inactive as they look, sponges rarely stop working if the conditions are suitable. In fact, they are continuously pumping water through their system at an incredible rate. They are capable of pumping a volume of water equal to their own body volume every 5 seconds!

So next time someone accuses you of “sponging”, don’t get offended – get angry. Angry that they used the term “sponge”. Then maybe show them the video below which, by the clever use of dye, reveals the hard work carried out by sponges everywhere.

Youtube clip uploaded by ProfessorZurawski

2 thoughts on “Weekend Sponging – Unsung Sponges”

    1. Thanks for the question Conor :) sponges have different pump rates between species and within species. Sponge volume has a large affect – as water is incompressible, the volume of water in to a sponge must equal the volume of water flowing out. So a large sponge will generally pump out a greater volume of water than a smaller sponge within the same time period. Sponges are also capable of slowing down pump rates if sedimentation increases. For example, specimens of a tropical marine sponge, Verongia lacunose, with a 500ml volume tend to pump out between 1 and 6 litres per hour. However, when exposed to suspensions of clay for four hours, this rate will decrease significantly (Gerodette and Flechsig, 1979).

Leave a Reply