A Well-Mannered Tunicate

So, on Fridays, I have Friday Noon Seminar. It is where other grad students present their work. This week, the presentation was on an odd kind of beast called a Botrylus. As a larva, it looks rather like a tadpole. When it grows up, it turns into a gelatinous blob which pumps water and eats the things it filters out.

The weird thing is that they form colonies via asexual budding. But these things are big and have clearly differentiated cell types, so there must be some strange regression to stem cells followed by differentiation going on there. They do this every week, in fact, with the previous week's "parent generation" going through a programmed death (they die even if you remove the child generation). The circulatory system, however, is common to the whole colony, and it remains intact even as the stomachs, reproductive organs (they have both sets), and what little brains they have are entirely replaced. This is a thing to study because it would be terribly useful if we humans could regress cells to stem cells and then regenerate organs in less than a week. Think of the lives which would be saved!

But I had never heard of a Botryllus before, so I asked the presenter right at the beginning, "What manner of beast is this?"

And he responded, "Pretty well-mannered," and so all the people laughed.