About two and a half months ago, the ongoing disaster of sea star wasting syndrome raised its ugly head again when one of my bat stars (Patiria miniata) developed lesions on its aboral surface. Here's what it looked like then:
and here's a close-up of the lesion, taken the following day:
See how the lesion is sort of fluffy? It looks as though tissue may be sloughing off the surface. Wanting to see how the syndrome would progress, I let it remain in its table and kept an eye on it. Every so often I took it out and examined it, and nothing really seemed to change. The animal continued to eat, retained its internal turgor pressure, and none of its table mates became sick. Eventually I sort of forgot about it.
Until two of my students last week asked if I had any pictures of sick sea stars that they could borrow for their end-of-the-semester project. This question jump-started my brain and I remembered this particular bat star, and told the students they could come to the lab and take their own pictures of it. . . that is, if it were still alive. They were able to visit me this past Monday and together we looked at the animal.
Lo and behold! it's not dead, and actually looks pretty good.
The star has a few pale areas in addition to the original lesions, but overall doesn't seem sick at all. It's nice and firm, righted itself quickly when we placed it in the bowl with its oral surface up, and crawled around very actively.
Not only that, but take a closer look at the lesion itself:
The lesion appears to be somewhat sealed off, as if the epidermis has recovered. I gently poked the surface of the lesion with my forceps, and it feels a little firm and nothing squirted out of or peeled off the surface of it. I think it's analogous to a scab that forms over a skinned knee. Of course, while a scrape on my knee would heal after a few days, sea stars have a much slower metabolism so I'm not really surprised that it would take over two months for this individual to show signs of a healing lesion.
Of course, I could be entirely wrong about what's going on with this lesion. It's the same size as it was back in September, so I'm not convinced that it's healing. However, it seems that closure of the wound is better than a wide-open gaping sore that leaves the animal's innards exposed to the external environment. If, over the next several weeks the edges of the wound begin to come together, then I'll be more confident that this animal is on the road to recovery. In this season on Thanksgiving, this is something to be grateful for.