Welcome back to another thrilling week of knowledge
Symbiodinium, or zooxanthellae, live a life that consists of two stages: one being more common than the other. The first stage of life is characterized by a small, oblong, body equipped with 2 flagella. This stage occurs before the zooxanthellae has found their home in a coral. The flagella is necessary for mobility in their journey through the big blue. This is called the motile mastigote stage. The most common stage is referred to as the coccoid stage. This is characterized by a spherical body that lacks flagella. This is the stage found dwelling in symbioses within the coral.
The grey arrows in the image above depict lab-observed actions. The red arrows depict inferences made. Symbiodinium reproduces asexually via fission. This happens through the mechanism of meiosis and daughter cells are identical to mother cells. The rate of meiosis depends on available nutrients and conditions. There are two possible outcomes that occur after this split. The motile phase could be spit out of the coral and find a new coral to inhabit or the motile phase could quickly transition to the coccoid phase to remain in the same coral. Reproduction has been created in a lab setting, but in the wild a coral is needed for reproduction to begin. The coccoid stage must be present for reproduction to happen.
A new question comes to mind after learning this. How does the coral get its symbiodinium?
This is legitimately a “chicken or the egg” scenario.
The coral can either swallow a zooxanthellae and have it enter its tissue OR maintain the mother and daughter cells that are reproducing inside its tissues already. It is thought that corals regularly spit out, swallow, and hold onto their symbiodinium to maintain a good number present in its tissues.
Are you getting hungry? I think its time to talk about food.
So what does a little zooxanthellae eat? Zooxanthellae are actually photoautotrophs. This means that they preform photosynthesis for energy and food. The coral provides the zooxanthellae with carbon dioxide and water to do so. The zooxanthellae then does photosynthesis and provides the coral with sugars, lipids, and oxygen.
1:27-2:18
That looks like the end of it for this week! Comment if you have any questions.
Hey Brittany, I love your post for this week (mind you I have not seen your other posts lol).
I love this post because it is very informative and I love the addition of gif’s and the short informational video. Any chance you can teach me how to upload a video? I only know how to hyperlink. Please and Thank you!
HAHA you know what is funny? Is that I also use the chicken or the egg scenario. I see that you referenced yours on how the coral obtained the zooxanthellae. Either way something tells me we will not know in our lifetime. I was just curious, if Zoozanthaellae live within coral and they perform photosynthesis, does this mean they live on the edge? I will need to visit your page!
Thanks (:
Hey Cristo!
Thanks so much for all of your kind words about my blog 🙂
I added the video through clicking the “add media” button and then adding a URL from youtube! Hope that helps
Hey there Brittany,
The zooxanthellae look like pretty cool microbes, especially in its relationship with the coral. It’s really interesting how the coral can either swallow the microbe or use it for its own benefit.
Also, your entire blog set up and appearance is so nice! The addition of various pictures and gifs makes the content seem so much more lively.
Hey Brittany! I love how your blog was able to capture my attention the whole way! The GIFs are hilarious. I myself went to the aquarium too and got to see these corals for myself. 😉 They are beautiful organisms that really need to be conserved. Their role is integral in the marine ecosystem.