Halteria?

[janvangastel]

This ciliate is about 30 microns in diameter. I think it is a Halteria, but don't know which species it is.

[D0c]

Looks like a Hypotrich.

I found some in one of my samples the other day.

[Bruce Taylor]

It looks and moves like Halteria. However, members of that genus should have equatorial bristles (used for abrupt jumping movements, which can be so quick that it looks like teleportation!). We don't see those bristles here, but maybe they are below the focal plane? Otherwise, I would consider it a likely oligotrich. Many oligotrichs lose their natural shape and become quite spherical under the coverslip (I often see this with Rimostrombidium lacustris, for instance).

Halteria were long considered oligotrichs, but recent molecular work shows they are probably hypotrichs. The lowest taxon that includes both Halteria and Oligotrichida is the class Spirotrichea.

[janvangastel]

Bruce, I don't know what you mean by equatorial bristles, could you please explain? From about 1:02 to almost the end of the video I have zoomed in at the moving bristles. How would you name these bristles?

[Bruce Taylor]

They are long, stiff bristles distributed around the equator (waist) of the cell. In this image by Michael Plewka they are marked with yellow arrows, and the adoral membranelles are marked with green arrows:


The jumping bristles are often missing from top-view images of Halteria, because of limited depth of field, but in videos we usually catch a brief glimpse as the creature scoots around. Your video clearly shows adoral membranelles, but I didn't manage to see the bristles. I still think this is probably Halteria, though. The "twitchy" movement is very typical, and Halteria is extremely common!

[janvangastel]

Thanks Bruce.If I find another one I will try to focus on the equatorials, if present.