dejayM's picture

Sea Spider

Observed: 3rd May 2013 By: dejayM
Biological Recording In ScotlandHighland Biological Recording GroupOrkney Biodiversity Records Centre
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live
Description:

I couldn't tell whether this was under- or top-side.
Near the bottom of the tide (mid tide range).
One of a number of 'items' from the 'Curiosity Shop' this morning.
Possibly Pycnogonum litorale (recorded in Orkney) but, if adult, too small.
>>WoRMS name<<

Identifications
Species interactions

No interactions present.

Comments

JoC's picture

Pycnogonum litorale

The  Marine Portal site for P. litorale gives 'Length of the body in females, taken from the tip of the proboscis to the posterior end of the abdomen up to 15 mm. The males are generally somewhat smaller.'
H & R gives 5 mm. So this could be an adult or a juvenile. I think it's the ventral view because I can see no eyes nor dorsal tubercles. There should be ovigerous legs visible on the ventral surface of a male, so this might be a female. But then again... it might not.
WoRMS gives the accepted spelling.
I would agree the species if you post it.
Jo

Jo

dejayM's picture

early post

Thanks Jo. nice work. I may not do that yet. There are two main reasons - this is the only sea spider I have ever seen and it was a very early post in my Marine career, so I cannot develop its identity very easily. The other main reason is that the features which might confirm its ID are absent from view.
Fish & Fish says, (of Pycnogonum litorale (both spellings)"..covered with tubercles..legs, with 9 segments, in males only.." And yet the diagram very closely matches this one and, to top it all, ...is the only one in Britain to live both on the lower shore and sublittorally (which may not be a proper word). You may consider that its size and other evidence is enough and I an tending towards agreement - would have done at the time but not quite now. I need another one..
Sufficient now though to know that we have both mentioned it as more than a possibility.
ð