Star reproduction?

[cathbad]

I have what Ophiura identified as a possible Ophionereis reticulata (about five years ago). It has been extremely durable but now has split into two apparently functioning "half stars" which continue to navigate about the tank each night and eat. Could this be asexual fission or something I should be concerned about? Nothing has changed and everything is stable. Any ideas are greatly appreciated.

 

[ophiura]

Hmmm...I would not consider it common in such a species. It is very common in six armed species. Are the halves regenerating at all? Can you get pics? As always, I would make sure parameters are in ideal range...have you done any recent water changes?

 

[cathbad]

This is the best so far. The disk looks to have been cleaved almost perfectly in half. In the red box is an edge-on view of the disk. It has been like this for about a week that I now about and it does seem to be a bit more sluggish but otherwise fine. Thanks for the help.

 

[ophiura]

If your parameters are in order, this will just have to be a wait and see. Ensure that it/they get food and watch for anything picking at it...may need to be moved to a refugium, or isolated within the tank in a critter carrier or similar.

 

[cathbad]

Update. For the past two nights, and once or twice several nights ago, I have seen two individual legs, in addition to the half pictured above, crawling about the tank. They seem to respond to food but there is no disk attached so, presumably, there is no way for them to eat. They come out only after dark just as before and hide during the day. There is a buccinid whelk that has been in the tank since day one and it pays no attention to the legs or any other "ambulatory" part. I wouldn't think that individual legs could live that long.