Luidia sarsii

Erling Svensen The Porania pulvillus have a lot larvae in the water now. They are just so nice and very beautiful.

Christopher L. Mah How do you know these are Porania pulvillus?

Christopher L. Mah there's pics of larvae from Luidia sarsi which appear similar http://blogs.wsj.com/photojournal/2011/09/21/beauty-at-the-bottom-of-the-food-chain/

Sabine Stöhr Hmm, the largest larva in our waters is Luidia sarsii. We get these in November when we run a systematics course at the Swedish west coast. Does Porania really have a similar larva?

Sabine Stöhr I took a photo a while ago and put it on the echinoderm newsletter here http://www.nrm.se/echinoderm

Erling Svensen Christopher: If you look closely at the seastar sitting on the larvae, you can see it. And - I just know as this is the only one like this in Norway.

Erling Svensen If you look at the Luidia sarsi - the star is not that compact as the Porania. http://www.google.no/imgres?imgurl=http://wwwdelivery.superstock.com/WI/223/4201/PreviewComp/SuperStock_4201-28450.jpg&imgrefurl=http://www.superstock.com/stock-photos-images/4201-28450&h=229&w=350&sz=31&tbnid=4LtmISuzwntuUM:&tbnh=90&tbnw=138&zoom=1&usg=__tKU8w_rfXNATertqbqsUTs46gs0=&docid=6kRVlTrHVD3QKM&sa=X&ei=gURQUobwBcqp4ATc4ICgDA&sqi=2&ved=0CD4Q9QEwBg

Jessica Marks Jeepers. I was unaware that Porania has a huge, stalked bipinnaria larvae like L. ciliaris and L. sarsi? Is there anything published on it? Sure it's not just a different stage? (This old reference on Porania pulvillus makes it look like a regular bip. larva - http://jcs.biologists.org/content/s2-61/241/27.full.pdf). Do they co-occur? Surely if L. sarsi is found off the western Sweish coast it occasionally occurs a wee bit farther north where I am? (I'm out-of-the-loop on Scandinavian seastar larvae so just wondering here).

Christopher L. Mah I'm sorry but unless you've verified this with something more rigorous like DNA or physically grown them out you really don't have a good basis for identifying this as Porania. A LOT of juvenile sea stars look essentially identical right at the outset. Larvae can be widely distributed.and L. sarsi DOES occur in Norway.

Sabine Stöhr The size and shape of the juvenile may change with age. If thse survive like this till mid-November they may easily change with growth.

Claire Goodwin We got a lot of very similar larvae off the scillies Erling . I was assuming luidia too. Will dig out picture if I get a chance - not as good as yours though!

Erling Svensen Ues, I know very well the L. sarsi. I did explain bad what I ment. So now I am quite open to this. Interesting..... http://uwphoto.no/shopexd.asp?id=16143

Christopher L. Mah I don't have access to the paper but I'm pretty sure your picture is the so-called "giant larvae" of Luidia sarsii as per Domanski - that also may explain how you photographed it. Most larvae require a scope to view... http://link.springer.com/article/10.1007/BF02180186

Christopher L. Mah The "star" is the rudiment which undergoes transformation and probably some reabsorbtion, so it will look very different following settlement and growth. Very little is known regarding Porania larvae. It would be one thing if you said, you saw this grown out through the different stages..but based on available evidence, this looks to me more like Luidia sarsi or something similar to it.