Eggs on detached seastar arm

Fish & Invertebrate sightings and descriptions, hosted by resident NWDC ID expert Janna Nichols (nwscubamom).
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YellowEye
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Eggs on detached seastar arm

Post by YellowEye »

Hi
I saw this at Redondo the other day.
DSC_3166.jpg
A detached sunflower arm, with what looks like eggs on the end of it. Anybody know what's up with this? Are these the eggs of the sunflower star? I assume they won't hatch?

=Eric
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ljjames
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Re: Eggs on detached seastar arm

Post by ljjames »

Great image... i can forward the image on to the echinoderm specialist i've been chatting with. So the mortality event is ongoing at Redondo? Would you be interested in doing some surveys for the Scientists up at Friday Harbor?
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YellowEye
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Re: Eggs on detached seastar arm

Post by YellowEye »

Hi
The seastars at Redondo are starting to die off now too, unfortunately. :(

I'm sure many of us would be interested in helping out any way we can.

Thanks for what you do.
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nwscubamom
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Re: Eggs on detached seastar arm

Post by nwscubamom »

Hi all,
Those are not eggs, but rather the insides (more specifically the gonads and pyloric caeca, whatever that is) of the seastar spilling out. Here is the progression of the disease from Neil McDaniel (and his photos):

Pycnopodia 10 shows this thinning in close-up. Note how distinct the edges of the rays look and how flat the star is.
Pycnopodia (10).jpg
Pycnopodia 21 shows how the body wall begins to rupture, allowing the gonads and pyloric caeca to spill out.
Pycnopodia (21).jpg
Pycnopodia 29 shows the gonads breaking through holes in the body wall. At this point rays often break off and crawl away briefly.
Pycnopodia (29).jpg
Pycnopodia 33 shows a star that has weaken to the point where it has lost its grip on the rocks and fallen to the bottom of a rocky wall.
Pycnopodia (33).jpg
Pycnopodia 15 shows the mat of bacteria at the foot of the walls and rotting stars piled up.
Pycnopodia (15).jpg
Just got a report this evening that it has reached Port Hardy and the seastars there are being affected.

- Janna :(
Janna Nichols
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ljjames
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Re: Eggs on detached seastar arm

Post by ljjames »

More details on the parts from Benjamin Miner:

The pink/orange round stuff is gonad, the greyish branching stuff is the pyloric cecum (which is a storage organ and collect directly to the stomach), and near the bottom of the leg where it looks like anemone tentacles is the water vascular system (the tube feet and gills are part of the water vascular system).
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YellowEye
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Re: Eggs on detached seastar arm

Post by YellowEye »

Interesting. Thanks for the info!
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