Palaemonetes varians

Erling Svensen This shrimp is very unlike others I have seen. Sitting on a Cyanea. The shrimp was 3 cm long. Anybody?

Chris Barrett Magnus Johnson, any thoughts?

Erling Svensen I have no clue what shrimp this is..... Pelagic, on a jelly...

João Pedro Silva I'm adding Ricardo Calado to the group for him to take a look at this.

Erling Svensen thanks. Hope he knows this strange shrimp.

Andy Horton I think it might be Pandalina ?

João Pedro Silva Ricardo, could you take a look at this?

Ricardo Jorge Guerra Calado Hi everyone. Was it swimming using the "feather-like" appendages above the legs? Was it swimming "backwards" (like tail firts)?

Erling Svensen Yes, it was swimming with the legs like the mysis.

Erling Svensen I can not say if it was swimming back or forwards. Sorry.

Ricardo Jorge Guerra Calado Is just that the feather like appendages above teh legs remind me of an advanced larval stage...

Erling Svensen Torleiv Brattegard, Norway said about the picture (Google translater): I think it is a post-larvae, which is the last stage before the shrimp turns on the bottom. It can be determined after the keys for the adult shrimp, but the picture does not show the detail needed for a secure identification. The picture is reminiscent of post larvae to fresh and brakkish shrimp Palaemonetes varians (which despite name can survive in normal sea water), but perhaps it is a different species within the family Palaemonidae. I have not enough literature is available. best Regards Torleiv

Andy Horton The sixth abdominal segment is elongate and unusual and not found in Palaemon species as far as I aware (hundreds of observations). But it does seem to occur in the Pandalidae (book knowledge only), including Pandalus. Species for ID for the Shetlands has a shorter but somewhat alike this one.

Andy Horton Palaemonidae have a distinctive rostrum with teeth which can be counted in large specimens. Young ones look just like the adults. Last abdominal segment is short.

Andy Horton http://www.getcited.org/pub/101893503 British coastal shrimps and prawns: Keys and notes for the identification of the species by Smaldon Hayward & Ryland (the green book) is good enough?

Andy Horton cf. http://www.facebook.com/photo.php?fbid=10150766812439065&set=o.112629298750125&type=1&theater

Espen Rekdal Anyone know this species? Found swimming pelagic on a night dive in a Norwegian fjord.

Erling Svensen Hi Espen. I did take a picture of a shrimp quite like this, pelagic on a jelly. I sent the picture to Torleiv Brattegard, specialist in crustaceans. He said it was a Palaemonetes varians - the postlarvae stage of the shrimp. I do not really know what this stage meen, but I have a feeling that it is a young shrimp. Maybe you know and can tell me?

Espen Rekdal Thanks for the tip Erling Svensen. This one is rather big, too big to be a postlarval stage I think? I guess it would be about 5cm long, 10-15cm with antennae.

Erling Svensen Well, "my" shrimp was also the same size as a adult, so I do now know. If you have someone to ask I would be interested. I will post my picture again and you can take a look.

Marco Faasse You might search the internet for Pasiphaeidae and Sergestidae. Any photos of details?

Espen Rekdal No not really. I do have a side view and a bit closer if that could help?

Marco Faasse I'm afraid not. I have no good knowledge of thia group, but this is a pasiphaeid: http://www.wrobelphoto.com/gallery/main.php?g2_itemId=1409

Marco Faasse and this is a sergestid: http://cifonauta.cebimar.usp.br/taxon/sergestidae/

Espen Rekdal Thanks anyway Marco.