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Well, maybe not

Against all odds, my last Pisaster star is (literally) hanging in there. It hasn't lost any more arms in the past 24 hours, and by the standards of the past two weeks that's a rousing success.

Pisaster star that lost two arms yesterday but no more since. ©2013 Allison J. Gong
Pisaster ochraceus star that lost two arms yesterday but no more since.
© 2013 Allison J. Gong

And it hasn't lost the turgor pressure of its body, so it isn't as limp as the others were before they died. I didn't want to mess with the animal too much, but it was pretty strongly attached to the table, indicating that the water vascular system hasn't lost all of its integrity. If that inter-radial area towards the top of the photograph is one of the areas where an arm was autotomized, the wound has healed surprisingly well. I will have to see what happens tomorrow.

On the other hand, the disease has spread to the lab next door, where a Pisaster giganteus started melting away two days ago. It was discovered with a small P. ochraceus feeding on the sick star, and the two stars have been since isolated. Today the P. giganteus looked horrifying:

Pisaster giganteus star melting from wasting disease. ©2013 Allison J. Gong
Pisaster giganteus star melting from wasting disease.
© 2013 Allison J. Gong

This is a really sick animal. There's a large wound on the bottom edge where an arm had been autotomized; it looks like the wound hasn't started healing at all. One of the remaining arms has twisted so that it is upside-down with the ambulacral groove--where the tube feet are visible--is facing upwards; that arm is probably going to be cast off soon. The beige-ish fluffy bits in the top of the photo are pieces of gut and water vascular system that are protruding through wounds in the body wall. I would be very surprised if this poor animal is still alive tomorrow. So far, the one that was feeding on this creature doesn't look diseased, so perhaps it will escape the pestilence.

2 thoughts on “Well, maybe not

  1. Margaret Perham

    Are the Monterey Bay Aquarium , California Academy of Sciences, or any other local institutions experiencing the same problem?

    1. algong

      I haven't heard, although I imagine that if they haven't yet they will soon.


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