Nick Upton's picture

Seaweed with little green fingers for ID

Observed: 23rd May 2013 By: Nick UptonNick Upton’s reputation in PlantsNick Upton’s reputation in PlantsNick Upton’s reputation in PlantsNick Upton’s reputation in Plants
Seaweed for ID
Seaweed for ID
Description:

I don't know this seaweed (a Brown alga I think) found in a Dorset rockpool and can't find a perfect match for it. A little like Codium fragile, but this has a more complex branching pattern. A little like Cystoseira tamariscifolia but no iridescence noted. Any suggestions welcomed!

Identifications
Species interactions

No interactions present.

Comments

dejayM's picture

thighs

I can't help much yet (inexperience) Nick but I must say it's nice to have someone else in the sea up to their thighs!
Good useful notes too.
You might be on the right track with Cystoseira
And try Laurencia obtusa
This is a nice visual site
http://www.seaweed.ie/descriptions/
Oh, I see it's a different route to the same site as your other post.
ðj

Nick Upton's picture

Thanks

Thanks for your suggestions, but I think we need expert help here...

If it is a Cystoseira, it didn't look like the stunning iridescing forms I've come across before e.g.: http://www.ispot.org.uk/node/289776 but might possibly be a different stage/growth form, but suspect it's something different again that I can't find a pic of. The site you mention is one I use a lot, but there are some missing images and not all are very clear.

Laurencia obtusata seems to vary a lot in form an colour, but no pics I can find match mine closely.

Nick Upton, naturalist and photographer.

dejayM's picture

hooray

It's gratifying that not only do you post interestingly, you respond to comments!
Hooray!!

JoC's picture

An interesting one, this.

I have been pondering this one since you posted it. I think the rather hairy clusters at the apices of this seaweed could be the reproductive organs. I have not seen these in life, and there are few photos to compare, but algaebase has something similar. So I am offering, for discussion, Cystoseira baccata.
"Receptacles 1-5 cm long, formed from axes of ultimate ramuli, irregularly nodose and bearing simple, filiform appendages. "
http://www.algaebase.org/search/species/detail/?species_id=92

Jo

Nick Upton's picture

Mystery seaweed

Thanks for the suggestion, Jo. I'd ruled that one out as it lacked the air bladders typical of the species, but the link you give suggests those are seasonal (autumnal), so maybe.... though I can't find any convincing picture matches. It's also described as growing in metre long fronds, and these were in small clumps, maybe 10cms max....but seaweeds do have so many growth forms... Still a mystery for me!

Nick Upton, naturalist and photographer.

JoC's picture

Still a mystery.

The size is helpful. So what we can see in the photo is the whole plant? I agree that makes a difference; I was thinking we could just see the tips of something much longer. Back to the drawing board...
Jo

Jo

Nick Upton's picture

Whole plant

Yes, that's all there was, though it's a late year and it may get bigger... Growing in a narrow, shallow channel (3 feet across less than a foot deep) across flat rocks exposed at low tide with water continuing to flow along it throughout the low tide period.

Nick Upton, naturalist and photographer.

JoC's picture

seaweed

Hi Nick,
if you are still watching your post - just to say I have not given up, but so far all my 'leads' have been unsuccessful. But I haven't given up...
Jo

Jo

Nick Upton's picture

Mystery..

Thanks Jo!

Nick Upton, naturalist and photographer.

PaulBrazier's picture

Brown alga - probably a red!

Hi, I am fairly sure that this is Gastroclonium ovatum, the branches are looking more elongate than I might expect. It is easy for such a red alga to be bleached to a brown or green, when exposed to the sun.

Paul Brazier

JoC's picture

Brown, green, red - or not a seaweed at all?

I was at the Coastwise North Devon Bioblitz at the weekend (excellent day),and I took along your photo, Nick, and showed it to some seaweeders. Jack, MBA, was passing and commented that he thought it was an animal .... which had not occurred to me at all. He pointed out that there seemed to be a pore at the top of the ‘vases’. I have been looking at some possibilities and I am now offering up for discussion a colony of the sponge Sycon ciliatum.
Paul has recently offered the red algae, Gastroclonium ovatum. Welcome to the discussion Paul, glad to have you on board.
This might qualify as the iSPOT post attracting most diverse id suggestions, currently from 3 different kingdoms.

Jo

Nick Upton's picture

Mystery weed/sponge

Many thanks Paul and Jo for your new suggestions.

An intriguing idea that this could be a sponge colony, which I hadn't considered, but if it is I don't think it's Sycon ciliatum as the circle of spines around the terminal openings are very distinctive - see http://www.marlin.ac.uk/speciesinformation.php?speciesID=4410 and I've never seen images of such tight colonies.

I do think Paul may be right with his Gastroclonium ovatum suggestion and the images of it on this excellent French red alga site http://nature22.com/estran22/vegetaux/rouges/rhodophyta3.php do look quite similar. I have come across some other very bleached red algae on the Dorset coast, maybe due to some very long low tide exposures due to the weird "double tide" patterns down there (due to water flowing either side of the Isle of Wight.

Nick Upton, naturalist and photographer.

dejayM's picture

moved on..

This, in my opinion (moved on since June!), is very untypical of Sycon ciliatum - see my post here http://www.ispot.org.uk/node/333468.
On the face of it, a tightly packed colony of same seems unlikely from the many descriptions in books and the webThing (particularly Google images)
But there is merit for considering it bryozoan, as it seems to have a symmetrical, plant-like, structure.
A 'gasping' colony of Hyalinella punctata?

Nick Upton's picture

Mystery seaweed/sponge/bryozoan

Hi dejay, thanks for broadening the diversity of suggested IDs even further; this could definitely become a record of some kind! I'm really not convinced it could be a bryozoan, though, as I see none of the distinctive features of these, and still favour the Gastoclonium ovatum red alga suggestion. I'll post a crop to try and show the structure more clearly, though it seems to be coated in some kind of jelly (or maybe a fuzz of tiny filaments) which doesn't help.

Nick Upton, naturalist and photographer.

JoC's picture

Well, I never!

Well, I never thought of G. ovatum, so I have been checking the books and I am minded to agree.
Linda Irvine 1995 Seaweeds of the British Isles Vol 1 part 2A.
“Dark brownish or purplish, occasionally greenish. Vesicles transparent, 7 (10) mm long and 1-2 mm broad usually spherical at first becoming elongate later… There is great variation in vesicle size but factors controlling this are not known; in the most luxuriant specimens they are segmented … such plants have been referred to Chylocladia ovata var subarticulata.” (Linda Irvine 1995 Seaweeds of the British Isles Vol 1 part 2A.)
WORMS now calls this Neogastroclonium subarticulatum (Turner) L.Le Gall, Dalen & G.W.Saunders, 2008.
Algaebase has convincing N. American photos, and a reference to Lily Newton’s book 1931, checks out as “segments oblong, very rare, Devon.” Lyme Regis isn’t far away.
http://www.algaebase.org/search/species/detail/?species_id=134252
There is no mention of the filaments which cover the vesicles, but they may be some epiphyte, saprophyte or parasite.

What do you think Nick?

Jo

Nick Upton's picture

Mystery solved....?

Hi Jo, Many thanks for your thoughts and input on this. I think we're very close and it may just be a matter of which of the synonyms to call it. There seem to be quite a few out there. Algae base has it as Claviclonium articulatum http://www.algaebase.org/search/species/detail/?species_id=2647&sk=0&fro... ( as search for G. ovatum on the site led to this).

No doubt this is one for taxonomists to argue over... and that counts me out.

It is recorded as G. ovatum for Lyme Regis: http://data.nbn.org.uk/speciesInfo/speciesSiteList.jsp?useIntersects=1&a...

My instinct is to call it that and I may put that name up, unless Paul Brazier can, as he came up with the ID which I'd now support.

As for the filaments - they could be a marine fungus, or possibly something to do with reproduction. Almost all the seaweeds in the area were spewing out gametes and isolated rockpools were a soup of floating blobs. These were in a gulley with flowing water, so it was a bit clearer.

Nick Upton, naturalist and photographer.

JoC's picture

Gastroclonium ovatum

I think that the species you have referred to in ALGAEBASE as Claviclonium articulatum is not our plant; that is the current name for Gastroclonium obovatum. Ours is just 'ovatum'.
I would support G. ovatum if you or Paul posted it.

Jo

dejayM's picture

a green red

I think Jo's on the right track (thanks to PaulBrazier) but all the media seems to be of a red appearance (I realise it's a Red Algae).
Gastroclonium subarticulatum is green (note the sub)
But there's a good pic here
http://thesaltyscavenger.blogspot.co.uk/2013/03/common-seaweeds-of-shore...
(of a green) Red grape weed (Gastroclonium ovatum). It takes awhile to come in and is way down the page.
It looks quite right.
ðj

dejayM's picture

Aufwuchs

After nearly a year, I am immediately struck by the growths on your weed here. Note the similarities to Jo's post in this Project 'Epiphytes or parsites [sic] maybe' and the delightful description aufwuchs!
ð
PS You have hyperlinks in the ID panel that are not hot and I believe they may be broken too. They might be worth renewing in a comment (for completeness). Such links in ID panels never seem to work.

Nick Upton's picture

Here's the first of those

Here's the first of those links again, hot I hope. Dunno why it went cold in the ID panel. The 2nd one seems to be defunct now.

http://thesaltyscavenger.blogspot.co.uk/2013/03/common-seaweeds-of-shore

Aufwuchs are new to me, http://www.ispotnature.org/node/371188 and I reckon my weeds are covered in them… whatever they may really be...

Nick Upton, naturalist and photographer.