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I could watch colourful ciliates like this Nassulid all day long, they’re like living kaleidoscopes! 🥹 Nassulids have been found in soils, freshwater and marine habitats in Europe, Africa, Asia, North America and Antarctica. They’re voracious eater of cyanobacteria, also called blue green algae, like Anabaena or Oscillatoria! The bright and beautiful colours characteristic of Nassulids comes from the digestion of cyanobacteria after being ingested by their mouth, called the cyrtos, nasse or pharyngeal basket, which is a microtubular complex that looks like a little fork! When cyanobacteria are ingested by the mouth, many small food vacuoles containing hydrolase enzymes are synthesized to breakdown and digest the food. The colour of those small bubbles (food vacuoles) depends of the pigments present in the ingested cyanobacteria; blue-violet globules comes from eating species that have phycobiliproteins like in Anabaena and pink-brown bubbles come from grazing on species that contains phycoerythrin pigments like in Oscillatoria. Basically, depending of what Nassula eats, it will appear different colours when the food is being digested! Some nassulids are being tested to control blue-green algae blooms in lakes; these blooms produce toxins that kill animals and other precious life forms. What I also love when observing nassulids is to see the contractile vacuole pulsing water out of the cell! The role of the contractile vacuoles is to regulate the osmotic pressure inside the cell. Imagine you’re on a boat with holes in it and you’re trying to keep the water out by filling buckets! That’s pretty much the role of contractile vacuoles, they’re the buckets of this tiny boat 🪣 Video taken with my iPhone mounted on a BA310E Motic microscope with an @ilabcam Ultra adapter 🔬 References: Canter, H. M., Heaney, S. I., & Lund, J. W. G. (1990). The ecological significance of grazing on planktonic populations of cyanobacteria by the ciliate Nassula. New phytologist, 114(2), 247-263. Lynn, D. (2008). The ciliated protozoa: characterization, classification, and guide to the literature. Springer Science & Business Media. Tucker, J. B. (1978). Endocytosis and streaming of highly gelated cytoplasm alongside rows of arm-bearing microtubules in the ciliate Nassula. Journal of Cell Science, 29(1), 213-232. .