parasites on a tintinnid ciliate

[Franz Neidl]

This are parasites (probably dinophyceae - Duboscquella tintinnicola?) on a marine tintinnid ciliate (Favella serrata).
Obj. 20x DIC, projection-eyepiece 2,5x

Franz

[RogelioMoreno]

Beautiful!

Rogelio

[Jan Kros]

Hello Franz
Very nice picture I have not seen this before.
Greetings
Jan

[elf]

Of the 6 hits for 'marine tintinnid ciliate', yours is by far the best. Which parts of the image are the parasites?

[Franz Neidl]

hallo elf,
thank you very muich! The small beads are the parasites.

Franz

[Bernd]

Dear Franz:

A very beautiful and very interesting picture. But are this really parasites? What puzzeles me is that the ciliate looks very similar to the one in your previous post, i.e. rather healthy. Also, the parasites are all located outside of the ciliates body and nowhere can I see any connection to the ciliate´s body. How can they feed on the ciliate? Do you have any additional pictures revealing more details about the nature of the organisms inside the lorica?

Greetings
Bernd

[Franz Neidl]

But are this really parasites? What puzzeles me is that the ciliate looks very similar to the one in your previous post, i.e. rather healthy. Also, the parasites are all located outside of the ciliates body and nowhere can I see any connection to the ciliate´s body. How can they feed on the ciliate? Do you have any additional pictures revealing more details about the nature of the organisms inside the lorica?

Hallo Bernd,

thank you very much for your interesting question. As I am not a specialist in parasites (I do microscopy as an hobby) I had to consult scientific literature in the Internet. Under "parasites of tintinnids" I found in "google books" an interesting articel from Jean Theodorides in "Advances in Marine Biology" volume 25 about "Parasitology of Marine Zooplankton". On page 129 - 130 you find drawings and a short description. But the question is very complicated. Theodorides speaks about a gametocyte becoming trophozoites, trophocytes, gametocytes and gymnospores.

Independently about the scientific literature I think it is not necessary that the parasite has to feed on the ciliate. Already the factum that it is transported and protected by the ciliate means that the ciliate is loosing a lot of energy, with other words it is damaged.

Franz

[BJ]

hi,

I have not been able to participate in the forum recently.....and what fantastic photos I have been missing !

Franz, once more you have produced a great photo and of a really interesting organism. A great photo because you have managed to get so much in clear focus in a subject which I am sure was swimming quite fast. I am sure that you are right and the parasite is Duboscquella ( note the spelling.... it is named after the French marine biologist and parasitologist Octave Duboscq (1868 - 1943)).

It was thought that there was just one species, but it is clear that there are several and that they may be host species specific (ie different species of tintinnid are parasitised by different Duboscquella species). The infective stage is a very small flagellate just a couple of micrometers in size. They are about the size of bacteria, the main food of tintinnids, so they are probably eaten by the tintinnid. Once in the tintinnid, the cell now feeds on the host and swells up to 80 - 100 um. It then exits the tintinnid cell and starts to divide within the lorica to produce a long chain of spores (maybe >100 cells). At this stage, it is no longer feeding on the host tintinnid cell. Franz has caught the parasite at an early stage of this division process. Division is extremely rapid and the whole process lasts only a few hours.

Franz, next time you find this, one cell in the chain should be larger than the others - this is the original parasitic cell which exited the tintinnid and gives rise to all the others in the chain.

It is amazing that the tintinnid is still swimming away...but it is obviously a seriously slimmed down cell... I wonder if it can recover?

Although traditionally classified as a dinoflagellate, Duboscquella is now classified as belonging to "marine alveolate group 1". This group of organisms is clearly related to the dinoflagellates and may be ancestral to them, but do not meet the strict definition of a dinoflagellate.

I suspect that this is the only "open- access" photo of Duboscquella on the web...and what a great photo it is.

Congratulations and thanks,

Brian

[Charles Krebs]

Franz,

Beautiful image. Clean, simple, and almost 3-dimensional in appearance.