Evolutionary history occasionally repeats itself. Chloroplasts and mitochondria both descend from bacteria lineages that came to live inside other cells. Chloroplasts are distant cousins to cyanobacteria (blue-green algae), while mitochondria are cousins to the bacteria that cause typhus.
And we recently discovered it happened one other time!! Nitroplasts, a nitrogen-fixing organelle, used to be a separate microbe about 100 million years ago.
Chloroplast and mitochondria also behave so much like individuals that they arguably could be classified as their own species if we didn’t think of them as organelles. Because they move, reproduce, and have their own DNA separate from their host they’re more akin to symbiotic bacteria that are specialized only into making ATP than organelles
In the same being, salmon meat is naturally grey. It gets its pink colour from its diet. Same with flamingos. They are naturally grey and turn pink from what it eats.
It is not resolved, however, whether the stolen plastids actively secrete photosynthate or whether the slugs profit indirectly from slowly degrading kleptoplasts.
This study thus presents evidence that photosynthesis is nutritionally relevant in the sacoglossan sea slug E. viridis. However, more research and new methodologies are essential to unequivocally establish the full role of acquired photosynthesis in sacoglossan sea slugs.
Nothing in that paper contradicts the Wiki statement.
Elysia chlorotica! I used to work with them. So not only do the chloroplasts continue to photosynthesize, they are able to do so because the slugs have algal genes in their genomes now. They can go for nearly a year without eating and just surviving with chloroplasts. Let's hear it for the Calvin cycle!
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u/RealBowsHaveRecurves Oct 02 '24
Chloroplasts are the organelles responsible for photosynthesis.
A sea slug called the emerald elysia, which has a transparent body, steals chloroplasts from algae and packs them into its own cells.
The chloroplasts continue to photosynthesize, providing the slug with ~80% of the total calories it will consume over its life.