Closterium preparing to divide

[Olympusman]

Closterium leibleinii preparing to divide. It appears it is venting out the old nucleus material.

[carlos.uruguay]

Very nice

[Ecki]

Venting out old nuclear material? I think the coverslip pressure is creating a crack and plasm is exiting. The algae is dying.

[Olympusman]

Ecki,
I see cracked Closterium all the time with their insides oozing out. However, I haven't noticed the gap and the rounded off shape of one half of the alga. Also, many of the Closterium I see dying show a "withering" of the insides with lots of empty space around the remaining green matter. I commonly see the rounding in new sections of recently divided Closterium. I'll look for other examples since C. leinleinii is pretty common right now.
I'll try to get an image of a crushed Closterium tomorrow.
Mike

[Olympusman]

This is what Closterium leibleinii looks like when the cell wall is ruptured by the pressure of a cover glass.







In my original image it appears the mattter from the area of the nucleus is "sloughing off" progressively. Since Closterium also reproduce sexually through conjugation, I would assume some sort of pore is involved to exchange genetic material. Anybody else closely observing Closterium?

[René]

Nah, it's just dying. It is not normal division, and for conjugation it should first form gametes that do not look like the vegetative cell.

Best wishes, René