Mystery blob

A Mystery Blob, photographed at 50x magnification.

I checked my dock study in Eel Pond yesterday, right on schedule. When I put the first fouling panel under the microscope, I was happy to see many of the same organisms I have come to recognize: spirorbids, hydroids, and a barnacle or two. I was chugging along, counting organisms, until something orange caught my eye. It looked like it was encased in a ball of mucus, so it might have been nothing. I increased the magnification on the microscope just to make sure.

What I saw was definitely not nothing, though what it is, I cannot say for sure. I'm calling it the Mystery Blob.

Once I saw the first Blob, a strange thing happened. I used the microscope to zoom back out, decreasing the magnification so I could see more of my panel, and when I did, my eyes started seeing Mystery Blobs everywhere! Once I had a search image for them, my brain was able to detect other Blobs on the fouling panels. They were actually pretty abundant.

So what is a Mystery Blob? I still can't say for sure, but my gut says it's an ascidian, also known as a sea squirt. Ascidians are tiny invertebrate animals that live in colonies and filter the water for food. They have the same squishy texture as my Mystery Blob, and I think the faint orange ring on the left side of the blob in the photo is a siphon, something all sea squirts have. If I'm right, then over the coming weeks, each Mystery Blob should grow into a colony, cloning itself over and over and spreading across the plate. Larger colonies will be much easier to identify than single, newly-recruited individuals. Hopefully, I can identify the Blobs to species soon!