Oh the life of a scientist! Currently, I am on Oahu, figuring out some kinks in my project because I am going to Taiwan on Tuesday! I will tell you all more about moorea, but my friend dusty was nice enough to post to my blog, an article on another project, non-marine that is going on down there. There is a group at the Gump station that has set out to try to document every living organism on Moorea (and in Tahiti in genera). they are the biocode people and mostly consist of native Tahitians. They are pretty rad! Anyways, check out the link dusty so kindly sent me! Enjoy!
Since you’re recently back from Mo’orea, check this out.
Promised egg/sperm bundles!
We got eggs last night! Not from the beautiful Fungia that I posted a picture of, but from Montipora verricosa (pictured below). I really think that these corals are beautiful.
If you look closely enough at this picture you can see a couple of things. First there are really obvious bumps on the coral surface, these are called verrucae. Surrounding the verrucae are small polyps (which is an individual). As a reminder, most coral colonies are made up of a lot of coral polyps (the exception was the last coral I showed you, the fungia which was made up of one polyp). Anyways, you can see the small polyps surrounding the colony. This feature is one of the defining characteristics of this species. The polyps look like faint pale circles around a darker interior. I hope you can find them!
When this coral spawns it releases an egg sperm bundle through the polyp. The bundle is probably twice the size of the polyps pictured above, so when the spawn their polyps get a lot bigger and we can tell when they are about to go. In the bundles you have a really lipid rich layer of fat cells that makes them float to the top of the water. Eventually they will break apart into egg and sperm and the eggs are very small red dots. The really cool thing is then they get fertilized by the other sperm in the water column! In order for this species to reproduce with other individuals, the colonies must be in sync when they spawn, so they tend to go around the same time of year, month and day. We have it down to a science (literally), this species will spawn during the summer months (in Moorea that’s December, January, February and maybe March) on or a couple days after the new moon between 8:00 and 9:00 pm. Last night was the new moon, so we got our egg/sperm bundles allowed them to fertilize and hopefully they will make little corals. One polyp at a time. (Pictures of the eggs to come soon!)
Bonjour de Moorea!
Life is beautiful down here in French Polynesia. The mountains are pretty and skies are blue and the sea is warm!
I am here working on a coral spawning project, in particular the group I am with is interested in assessing the microbial communities associated with corals in Moorea and Hawaii. So I have been sitting and watching corals try to release eggs. But it got me thinking about coral polyps. A polyp is an individual coral and usually they live in a clonal community that makes up a colony and what we normally consider a whole coral. so many polyps make up on coral head. The coral polyp in the picture below is one single polyp and lives a solidarity life style, or on its own. But whats cool is that is clearly shows what an individual polyp looks like. It has tentacles that pass food particles in the water to it’s mouth which is the middle part of the individual. The food goes into the mouth and is digested and then the waste leaves again through the same mouth. When the coral releases its gametes (i.e. eggs and sperm) they are also released through the mouth. The pigment on the coral skeleton is made from the symbionts (which are algae that fix CO2 and produce carbon for more coral nutrition) and cretinoid pigments. So all in all, a coral polyp, by itself, is pretty simple.