Teuthophrys, continued

[Rene]

Following up on Holger's presentation on Teutophrys last Sunday ( enjoyed it very much, thanks Holger!), here are a few more photos of a distinctive feature of this magnificent beast: the dorsal brush. It runs lengthwise along one of the creature's arms, and of course never on the 'easily accessible' imaging side.

Google tells me that the dorsal brush is involved as a sensory organ for chemical or tactile stimuli. Intriguing idea, but I have no idea how that would work, or how to test such a hypothesis...

Best, René

[Spectrum]

Hello René,
Just when one might have thought it couldn't get any better—you've delivered even more masterpieces!!!
Fantastic!
And yes, the hypothesis regarding the role of the dorsal brush is precisely what it is (an as-yet unproven conjecture).
But there strong indication for the thesis that this specialized cilia are chemical or tactile sensors based on their ultrastructure.
There is a paper from 1988 about Prorodon and it's dorsal brush about exactly this topic:
https://www.researchgate.net/publication/256659240_Prorodon_aklitolophon_nspecand_the_Dorsal_Brush_as_a_Character_to_Identify_Certain_Subgroups_in_the_Genus_Prorodon

One of the authors is Stephan Hiller btw.

Hallo René,
Gerade als man dachte, es ginge nicht mehr besser – da lieferst du noch mehr deiner Meisterwerke ab!
Fantastisch!
Und ja, die Hypothese zur Rolle der Dorsalbürste ist genau das, was sie ist: eine bislang unbewiesene Vermutung.
Doch aufgrund ihrer Ultrastruktur gibt es starke Hinweise auf die These, dass es sich bei diesen spezialisierten Cilien um chemische oder taktile Sensoren handelt.
Es gibt eine Arbeit aus dem Jahr 1988 über *Prorodon* und dessen Dorsalbürste, die genau dieses Thema behandelt:
https://www.researchgate.net/publication/256659240_Prorodon_aklitolophon_nspecand_the_Dorsal_Brush_as_a_Character_to_Identify_Certain_Subgroups_in_the_Genus_Prorodon

Einer der Autoren ist übrigens Stephan Hiller.

[Rene]

Ah, I forgot how many specialists are on this Forum, what a great place this is!

Lab to Dr Hiller: come in please Dr Hiller 

Best, René

[anne]

Dear Rene,
these images are unique!
As I am a bit included in the Teutophrys story I really enjoy them very much and have to say thank you!
best
anne

[Jürgen Boschert]

Hi Rene,

many thanks for these outstanding images.

[rhamvossen]

Hi René,

Pictures liked these make you realise how complex such protists already are. Think about the coordinated movement of all those cilia. Great images! Best,

Rolf

[Rene]

Thanks for all the encouraging words! Quite fun being involved in such a project, certainly the collaboration with amateurs/hobbyists/volunteers/dilettants/citizen scientist (pick your favourite) is very valuable.

Last addition I can make is an image of a shape that Holger sees as an early cyst of Teuthophrys.

Best, René

[Spectrum]

Hi René
Well, to be precise, it would be more accurate to say that this is likely a young cyst.
Specimens that have been starving for an extended period retract their proboscides and take on an increasingly spherical appearance:



Initially, these spheres still move slowly, circling in place.
After a while, this movement ceases, and something resembling a solid shell forms:



However, in my cultures, all of these spheres have so far burst and died:



I am therefore still a bit cautious about stating definitively that this is encystment. You should take this with a grain of salt. But it certainly looks like it.
Greetings Holger

[Rene]

Thanks for the correction and the additional photos Holger!