Photosynthetic animals?

Photosynthetic animals?

We just started topic 8.3, photosynthesis, in Biology HL. One of the first things we were talking about were if plants, fungi, algae and some microorganisms were the only ones that could get energy via photosynthesis. We discovered then that that isn't true. First of all we looked this video:

https://www.youtube.com/watch?v=AcX2n1rC4W4

(Since I started IB Hank has became one of my closest friends)

So It's true that there are animals that use photosynthesis for getting energy from the environment and accumulate it as ATP. And only that, There also vertebrates which do that. It is true that they are not fully photosynthetic (except of the first one which has to eat for their first weeks), but still, that animals have evolved to create a type of symbiosis (or at least mutualism) between them and photosynthetic creatures for harvesting energy.

Another animal that we checked in our last lesson was a specific type of jellyfish that only lives in one specific lake an specific island of indonesia which has living algae on them and they live in a completely symbiotic relationship. The Algae provides the energy needed by the jellyfish for surviving and the jellyfish moves towards the sun, facilitating the algae's work, and also protecting it from the outside.

I just see that the possibility of having photosynthetic animals in the actual world (Which means that there's a possibility of humans also being able of doing that in a far future) absolutely amazing.