dejayM's picture

Paddle worm

Observed: 27th August 2013 By: dejayM
Biological Recording In ScotlandHighland Biological Recording GroupOrkney Biodiversity Records Centre
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size
mobile - snake-like
head
sketch (from a photo)
tail
mid
pressure
Description:

A paddle worm (Phyllodocidae)
A lively, matchstick-sized, narrow and segmented worm. Overall light brown but with a greenish tone, particularly at the head end.
At its mobile-stretched length about 5cms but maybe a little longer when fully extended. About 72 segments, each of which had a bristle-terminated leg or paddle.
See Comments
Core edit
Added 7th Picture

Identifications
Species interactions

No interactions present.

Comments

dejayM's picture

naked zones

It is quite like Eulalia viridis (green paddle worm), though far less green than the name, or Web-references suggest; also the head and naked area in Zone 2 suggests otherwise. It may indeed be an Eulalia but even with the detail shown in the Hayward & Ryland handbook it does not, quite, match them.
Using the text-key in H&R I progress, unconvincingly, to Pseudomystides limbata but then the position of the 'eyes', the unsegmented antennae and the lack of the 'naked Zone 2' seem to rule it out.
However, there are a number of records (via NBN) in Orkney, though a little dated
Lateral delving projects me towards the unromantic Ragworm (Hediste diversicolor) which might have the naked zone.
OBVIOUSLY then, I need support!

JoC's picture

paddle worm

I looked in H & R for any diagrams of paddleworms with a naked zone (I have not often looked at paddleworms that closely myself) Your head photo and drawing looks like a Nereidae, and I thought Nereis pelagica looked a good match; the description does not offer any contra indications as far as I can tell. It even mentions the greenish metallic sheen.
What do you think?

Jo

dejayM's picture

..typically errant polychaetes

Lovely Jo..
There's something quite compelling about the Russian drawing here (пХЯ .68) http://e-lib.gasu.ru/eposobia/bondarenko2/zan13.htm
Here too - http://www.discoverlife.org/mp/20q?search=Nereis+pelagica there are some 'remarkable' similarities to MY drawing.
The most similar, very convincing, one is here
http://eol.org/data_objects/22886873

It shows, doesn't it, that a drawing is as important as a photo but, beyond all, close observation is the key.
However, Jo, there is a marked absence of the imposing jaw-structures ("two curved chitinous jaws"..."small horny teeth (paragnaths)") mentioned in the H&R text and seen in the diagrams and, generally, the detail seems to be dissimilar in more respects than I'd like.
I was very close to putting up the ID and a few more words of your remarkable wisdom may clinch it.
I really hope this does not dampen your commitment!

dejayM's picture

Second thoughts

I have fretted for nearly an hour...
All the web photo-evidence is clear. This IS, as you suggest Jo, Nereis pelagica.
Nothing is clearer than the microphoto here http://www.discoverlife.org/mp/20p?see=I_MWS74789&res=640 from which you may conclude, incorrectly, my drawing is taken. The detail is perfect, the likeness uncanny and the mention of 20p in the link-script? Explain that!
I see, now, that the jawed proboscis is evertable. Only when angry or hungry then! My quest then is to make one angry enough.
There are no NBN records of this worm in Orkney - plenty for N.longissima (one wonders..)

JoC's picture

Nereis pelagica and new for Orkney? Good one.

And fret not; anyone can see that your diagram is an accurate depiction of your photo posted alongside.
You don't have to make a Nereid very angry; 'Pressure applied behind the head will cause the worm to evert its proboscis.' H&R page 206 in my copy.
I was surprised by the 20p reference too, until It was suggested to me that it may refer to the numbering system. There is a -20q link in your earlier posting.

Jo

dejayM's picture

number 007

Added some pressure on another - picture 7.
Made its eyes pop but no sign of those fierce little jaws. Clearest anatomical yet.
ð

(RUTH BARNICH)
I really feel I should add this link for anyone who may come here -
http://www.nmbaqcs.org/media/10825/barnich_british_scale%20worms_pictora...