the marine alga Tasmanites (pelagica ?)

Franz Neidl · Post by **Franz Neidl** » Thu Jan 23, 2014 3:44 am

I think this is the marine alga Tasmanites pelagica. Somebody can confirm it? (I am optimistic because in the web there are always some experts - this was my experience some days ago with the polichaeta!)
1 photo (stack with 4 pictures).

Franz

Jacek · Post by **Jacek** » Thu Jan 23, 2014 4:20 am

Franz, long you were gone, a great photo. What lens?

carlos.uruguay · Post by **carlos.uruguay** » Thu Jan 23, 2014 10:31 am

I don't know which algae is it, but the photo is excellent

Ken Ramos · Post by **Ken Ramos** » Thu Jan 23, 2014 7:30 pm

That is cool

Wonder what all those tiny pores are all about, gas exchange

Ernst Hippe · Post by **Ernst Hippe** » Sat Jan 25, 2014 2:55 am

Franz,
according to Hoppenrath et al, Marine Phytoplancton (page 216), 1t could be Halosphaera cf. viridis (Prasinophyceae)? This book shows alo a diatom Actinocyclus sp. (?).
Regards Ernst

Franz Neidl · Post by **Franz Neidl** » Sat Jan 25, 2014 9:53 am

Hello Ernst,

thank your for your answer. I don't think so (in the moment!) that this is Halosphaera (viridis?). I find Halospaera (viridis?) always green coloured. Anyway: also Tasmanites is from the Prasinophyceae-family.
Unfortunately I dont have the book from Mona Hoppenrath (I know I should finaly buy it!). Would it be possible for you to scan page 216 and send it to me per email?
Franz

Hello Jacek,
you are asking "what lens". It was a Nikon 40, plan apo.
Franz

RogelioMoreno · Post by **RogelioMoreno** » Sat Jan 25, 2014 1:39 pm

Nice picture!

Rogelio

Ernst Hippe · Post by **Ernst Hippe** » Sat Jan 25, 2014 2:32 pm

Hallo Franz,
I made a scan and will send it to you per E-Mail. Please give me the adress per PM.
Regards Ernst

René · Post by **René** » Sat Jan 25, 2014 2:37 pm

Hi guys,

Franz's image shows a clear double wall. It is therefore Pachysphaera, not Halosphaera (P. pelagica seems to be the obvious choice). As far as I am aware Tasmanites is reserved solely for fossil taxa.

Best wishes, René

BJ · Post by BJ » Sun Jan 26, 2014 12:01 pm

hello Franz,

i think that your ID of Tasmanites is spot on - one feature is the colour - quite a dull green - not the bright green of Halosphaera for example. Unfortunately I cannot remember the characteristics of the two (? or more ) species.

My recollection is that fossil specimens and recent specimens show identical wall structure and therefore may be considered to be the same organism. Tasmanites was named first and therefore has nomenclatural priority over Pachysphaera.

I am impressed (as I usually am by your photos !) that you managed to get so many of the pores in sharp focus - even with stacking.

Thank you for another interesting post.

Brian

René · Post by **René** » Sun Jan 26, 2014 12:11 pm

Oh yes, Ernst, good suggestion. Actinocyclus (more specifically A. octonarius) shows the same characteristics to this thingy: a wall which shows fine stripes (which are pores) and more or less scattered pores on the surface. But Actinocyclus is a diatom with green chloroplasts around a clear protoplast (mostly vacuole, I should add). This thing howevver, is a prasinophycean plate with contents that resemble Brussels sprouts

Best wishes, René

Franz Neidl · Post by **Franz Neidl** » Sun Jan 26, 2014 2:00 pm

Many thanks to everybody for the vivid discussion. I found some literature in the web about this alga:
According to BOALCH G.T. there is not distinction between the fossil and the recent alga (Pachysphaera pelagica). Therefore the right name is Tasmanites pelagica (as also Brian is saying):
http://www.jstor.org/discover/10.2307/1 ... 3400203923

about the distiction between Pachysphaera pelagica and Pachysphaera marsshalliae Teyssedre, B., Les algues vertes..., Annexe Nr. 5 (2006) is writing "PARKE (1966) a décrit avec precision le phycome de Pachysphaera....... Pour le specimen rapportés à Pachysphaera marshalliae ces pores sont de deux calibres différants alors que ceux de P. pelagica sont tous du meme calibre. C'est d'après ce critère que PARKE (1966) a distingué les deux espèces" 33-34.
http://paleopolis.rediris.es/cg/CG2006_BOOK_01/

My conclusion: I think that this alga is Tasmanites pelagica.

Franz

René · Post by **René** » Sun Jan 26, 2014 3:51 pm

Hmm, taxonomy has this annoying tendency to evolve at at way quicker pace than the organisms it describes. Under the Saint Louis Code, Boalch's suggestion has been reversed some 10 years ago: http://www.bgbm.org/iapt/nomenclature/c ... c3a011.htm, Ex. 28

Best wishes, René