Comments on: Aphids May Harvest Solar Energy Like Plants

By: Julius Csotonyi

Julius Csotonyi — Tue, 28 Aug 2012 16:20:09 +0000

Joe Real and JeffB: Although the sea slug _Elysia chlorotica_ sequesters chloroplasts from algae, these chloroplasts can only be maintained temporarily (even though the slug possesses some maintenance genes from the algae that may help keep the chloroplasts alive for a while). Further, a lot of animals and fungi engage in symbiotic relationships with photosynthetic algae or cyanobacteria in order to acquire additional nutrients indirectly via photosynthesis by their symbionts.

However, there may be a qualitative difference with the aphids. They may be the first known animals to possess enough of the genes needed to encode a functional set of the biochemical machinery of photosynthesis (albeit a truncated form, probably without the complex light harvesting antennae complexes and reaction centers found in plants, algae and photosynthetic bacteria). Hence, these aphids need not rely on a symbiotic partner to perform a form of photosynthesis.

You can remove a symbiont from the sea slug or coral and the animal will be simply heterotrophic, but the aphid remains (potentially) photosynthetic without any additional symbiont. Among other things, this kind of possession of genes makes the process potentially more stable. Consider that corals, which rely on algae for their photosynthetic capabilities, can “bleach” under certain conditions (meaning that they expel their symbionts, causing the corals to lose their green color, which is due to the pigments of the algae), and without their symbionts, their fitness is reduced.

By: JeffB

JeffB — Thu, 23 Aug 2012 13:41:40 +0000

Not just the green sea slug. Giant clams are photosynthetic, and a great deal of corals are as well. It’s something that aquarium keepers have had to deal with for a long time. Until recently it was very difficult to even get enough light on a coral tank without running up an electric bill that would get you investigated for running a grow op.

By: Joe Real

Joe Real — Tue, 21 Aug 2012 16:47:13 +0000

This is not surprising. There is an animal, a green sea slug, that even does more than these aphids. The animals obtain chloroplasts from the plants that they eat, and then use the chloroplasts for photosynthesis, to supply them with their own food. These animals can do photosynthesis and it keeps them alive without any food. These are considered half-animals and half plants, so could be an entirely separate taxonomic kingdom, just like lichens which are part fungus and part plants in character. It is good to know that to a certain extent, aphids have these ability to use solar energy too. Here’s the old article about a photosynthesizing sea slug:

http://www.msnbc.msn.com/id/34824610/ns/technology_and_science-science/t/sea-slug-surprise-its-half-plant-half-animal/

By: Joe Terry

Joe Terry — Tue, 21 Aug 2012 13:50:47 +0000

I’d be more interested in ATP/ADP ratios, especially how they change under the experimental conditions.

By: Isabel

Isabel — Tue, 21 Aug 2012 02:00:55 +0000

“most organisms get carotenoids from food”

Do you mean most animals?