Which Spathidium is this with a "head" so big?

[NachoBen]

I'm sorry to say that I have given up after searching for this critter in Kahl's work and in Foissner's Monograph on the Spathidiida. Perhaps amphoriforme?

From wet moss (maybe muscorum?)



Any help heartily welcome!

[Ange20]

Great capture!!!
What setup do you use?

[NachoBen]

I am glad you liked it!

This my everyday setup (for now):

Microscope: OMAX - M837ZL-C180U3 https://shorturl.at/hBKLN

Objectives: 4x, 10x and 40x from the pack, and 60x objective (dry) (model AmScope A60).

Eyepiece: 10x from the pack inserted in the photographic tube.

Smartphone to eyepiece adapter. https://shorturl.at/bqCD9

Smartphone: Xiaomi Redmi Note9, using the 5 Mpx macro lens and the Open Camera app.

Videos processed with InShot app on the smartphone itself.

[Bruce Taylor]

On the basis of the cell shape, I think it's likely to be a species in the S. amphoriforme complex. It somewhat resembles S. securiforme (previously a variety of amphoriforme, elevated to species level in 2017). However, there really isn't much to go on, here, except for the coarse morphology. We don't see extrusome, macronucleus, kineties around the mouth, etc., so even the genus is questionable. There are now far more spathidiid genera than were known in Kahl's time (e.g. Pharyngospathidium, Arcuospathidium, Protospathidium, etc.) and the morphological criteria for these are not visible in dark field at low magnification.

[NachoBen]

Once again I have to thank you, Bruce. Not only for your kindness and skill, but for forgiving me for the use of the dark field while I attempt to accurately determine a critter. Shame on me.

I stick to S. amphoriforme complex.

On the basis of the cell shape, I think it's likely to be a species in the S. amphoriforme complex. It somewhat resembles S. securiforme (previously a variety of amphoriforme, elevated to species level in 2017). However, there really isn't much to go on, here, except for the coarse morphology. We don't see extrusome, macronucleus, kineties around the mouth, etc., so even the genus is questionable. There are now far more spathidiid genera than were known in Kahl's time (e.g. Pharyngospathidium, Arcuospathidium, Protospathidium, etc.) and the morphological criteria for these are not visible in dark field at low magnification.