Algal Reproduction

Post your images made through a compound microscope or made with a stereo/dissecting microscope in this gallery. Images may be of any subject natural or unnatural, living or non-living.

Moderators: MacroMike, nzmacro, Ken Ramos, twebster, S. Alden

Locked
User avatar
micron
Posts: 294
Joined: Sat May 29, 2004 6:52 am
Location: Delta, BC - Canada
Contact:

Algal Reproduction

Post by micron »

Image

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.

User avatar
Ken Ramos
Site Admin
Posts: 4809
Joined: Tue May 04, 2004 7:58 pm
Location: Western North Carolina

Post by Ken Ramos »

Excellent images Ron. I have seen this in Spirogyra but never in Zygnema. :D
Site Admin.
Kenneth Ramos
Rutherfordton, North Carolina
Kens Microscopy
Reposts of my images within the galleries are welcome, as are constructive critical critiques.

User avatar
micron
Posts: 294
Joined: Sat May 29, 2004 6:52 am
Location: Delta, BC - Canada
Contact:

Post by micron »

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!

User avatar
Ken Ramos
Site Admin
Posts: 4809
Joined: Tue May 04, 2004 7:58 pm
Location: Western North Carolina

Post by Ken Ramos »

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.

User avatar
piotr
Posts: 445
Joined: Wed Apr 28, 2004 8:44 am
Location: San Diego
Contact:

Post by piotr »

Beautiful sequence, Ron! I haven't seen conjugating Zygnema before.

As for Paramecium, I found that sometimes one can 'force' them to conjugation by mixing two droplets coming from independently prepared cultures.
Piotr

Garry DeLong
Posts: 38
Joined: Mon Apr 04, 2005 4:56 pm
Location: Portland, Oregon USA

Post by Garry DeLong »

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

Locked