Algal Reproduction
Moderators: MacroMike, nzmacro, Ken Ramos, twebster, S. Alden
Algal Reproduction
Here are three pictures illustrating the process of sexual reproduction in the filamentous algae Zygnema. Picture 1 shows the vegetative filament, picture 2 the conjugating filament, and picture 3 the zygotes formed after migration of the male gamete into the gametangial cell containing the female gamete.
Excellent images Ron. I have seen this in Spirogyra but never in Zygnema.
Site Admin.
Kenneth Ramos
Rutherfordton, North Carolina
Kens Microscopy
Reposts of my images within the galleries are welcome, as are constructive critical critiques.
Kenneth Ramos
Rutherfordton, North Carolina
Kens Microscopy
Reposts of my images within the galleries are welcome, as are constructive critical critiques.
I picked the algae up in a local ditch. The algal mass was very dense, floating on the surface. It contained Spirogyra and Zygnema both undergoing sexual reproduction. I suspect this was brought on by the rather crowded conditions, as environmental stress is often the reason filamentous algae turn to sexual rather than vegetative reproduction. Of course our persistent cool wet weather may also be a factor - it is definitely stressing me!
Ciliates, i.e. paramecium, will sometimes exhibit the same behavior (conjugation) when stressed, I have read.
Site Admin.
Kenneth Ramos
Rutherfordton, North Carolina
Kens Microscopy
Reposts of my images within the galleries are welcome, as are constructive critical critiques.
Kenneth Ramos
Rutherfordton, North Carolina
Kens Microscopy
Reposts of my images within the galleries are welcome, as are constructive critical critiques.
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- Location: Portland, Oregon USA
Indeed so, Piotr. I have been told that ciliates generally will not conjugate unless the genotypes are different. If you have two seperate cultures of the same species of organism, combine portions of each culture and more often than not, you will get conjugation. This works with Spirostomum too. Jennings (1944) asserts that in some conjugation events, at least in Paramecium, instead of an increase in vitality, there occurs a lethal gene combination resulting in the death of the conjugates, so I suppose it's possible to see conjugation followed by a sudden decrease in population, with only the unsuccessful suitors remaining--perhaps an analogue of human STD carried to extreme.
Garry DeLong
Garry DeLong