Sargassum Stowaways, Part Two
After figuring out how to find the critters hiding in the sargassum, I couldn’t help but do the same thing again the next day. I didn’t really change my technique, but I figured I would post Sargassum II: Crustacean Bugaloo anyways.
If you’re curious about the technique for photographing them, it was pretty simple. I used a coffee filter to strain the sea water so it was relatively clear and put it into a clear glass bowl with a little flash on each side, triggered by my camera. To get underwater, I just used the flat port from my camera housing, holding it in the water with one hand while I pointed the camera with the other. I think a better approach would be to use translucent container (like tupperware) that would act as a diffuser and put a matte-finish bottom inside the container maybe either black or white. Perhaps I can try this next time.
Below are a whole mess of photos of shrimp and crabs. One thing you might notice on many of the shrimp is a lump on one side of the thorax. These are isopods which parasitize the shrimp. Specifically, they are from suborder Epicaridae, which includes a variety of isopods that parasitize crustaceans (or actually, other crustaceans, because isopods themselves are also crustaceans). The females, which are much larger than the males, attach themselves to the gills of their shrimp hosts and feed on their blood. Often, and it looks to be that case in these photos, the shrimp actually grow their carapace over the isopod, creating the lumps you see in the photos (compared to the symothoid isopods you can see on fish, where the isopod itself is visible). Also, there was one free-swimming isopod that you can see below, it’s dark and curved.
