Sponge pumps and evolution of the sponge body plan

Thursday 03 Dec 20
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Seyed Saeed Asadzadeh
Postdoc
DTU Aqua

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Thomas Kiørboe
Professor
DTU Aqua
+45 35 88 34 01

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Poul Scheel Larsen
Professor Emeritus
DTU Mechanical Engineering
+45 45 25 41 70

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Jens Honore Walther
Professor
DTU Mechanical Engineering
+45 45 25 43 27

Pumping units in most sponges possess a gasket structure ensuring efficient pumping and filtration. However, some sponges lack such structure in their pumping units and it is an open question how they manage to pump and filter. In a recent eLife paper, we address this significant puzzle by demonstrating an unusual flow pattern that accomplishes pumping and filtration, and suggest implications for our understanding of the evolution of the first metazoans.

Sponges are biological pumps that use flagellated collar-cells to filter several hundred times of their body volume daily. The existence of three grades of sponge body plans has long been known but whether these correspond to evolutionary differences in mechanics of the sponge pump is poorly understood. We demonstrate how morphological differences in the pumping unit of sponge body architecture is directly related to the hydrodynamics of operating conditions. We combine numerical and experimental work, and demonstrate how sponges that lack such sealing elements are able to efficiently pump and force the flagella driven flow through their collar filter, thanks to the formation of a ``hydrodynamic gasket'' above the collar. Our findings link the architecture of flagellated chambers to that of the canal system, and lend support to the current view that the sponge aquiferous system evolved from an open-type filtration system, and that the first metazoans were filter feeders.

 

Read the paper here: https://elifesciences.org/articles/61012

 

Asadzadeh SS, Kiørboe T, Larsen PS, Leys SP, Yahel G, Walther JH (2020) Hydrodynamics of sponge pumps and evolution of the sponge body plan. eLife. DOI: 10.7554/eLife.61012

 

Header image: Calcareous sponge Sycon coactum

https://www.oceanlifecentre.dk/news/Nyhed?id=%7BAC37A6FF-C1AF-48F0-BE8A-EF6B724F18B8%7D
22 APRIL 2021