Tintinnids: marine microorganisms essential to the ocean ecosystem

When it comes to classifying living creatures, naturalists have been tidying up for almost three centuries. But what can we do, alongside the classic kingdoms of animals and plants, with micro-organisms, such as bacteria? And the mushrooms? And viruses?

For fifty years, the pattern has continued to become more complex in the form of new groups, “domains”, “empires” and new “kingdoms”. In 1993, for example, the Chromista empire was proposed to bring together marine microorganisms such as protozoa, certain fungi and microalgae. Among them, the tintinnid family stands out in particular for the characteristic representatives of the species T. campanula, which is in the shape of a bell.

They are actually single-cell organisms with cilia to feed on algae and bacteria. These organisms are housed in a protein shell called lorica, tiny “bells”; smooth, sometimes with rings or numerous grains of minerals clumped on their surface.

Thanks to a retractable peduncle, the animal made up of a single cell can thus take refuge in its shelter in the event of a threat. These creatures which filter seawater contribute to the good condition of this marine environment, particularly in the South Atlantic where their concentration is very high. A necessary abundance since they form an essential link in the marine food chain.