Desmids, Diatoms and Green Algae

1.Conjugating Green Algae

http://en.wikipedia.org/wiki/zygnematales

Mougeotia

 

Mougeotia is an unbranched green alga that is circular in cross-section. It was found sparsely throughout the bog in the spring and early summer. The filamentous green alga reproduces sexually through the process of conjugation. Conjugation tubes connect two adjacent filaments as shown below, and the haploid nucleus of one cell passes through the conjugation tube and joins the haploid nucleus on the other side (Fertilization). The resultant diploid cell (Zygospore) will eventually form an unbranched filament. As you can see, the algal population is deteriorating eventually leaving only the zygospores (not seen) to re-establish the population in the spring.

2. Desmids

http://en.wikipedia.org/wiki/desmid

Desmids are a group of green algae that are composed of two halves connected by a relatively thin connection called the isthmus., Each half has one chloroplast. They reproduce by conjugation, described above. As one might suspect, they are closely related to the conjugating green algae. They are the most abundant algal group in the HVNC bog. The genera listed below were present from early spring to the end of summer.

a. Micrasterias

http://en.wikipedia.org/wiki/Micrasterias

http://vimeo.com/86535355 (Zottoli) (Micrasterias)

b. Netrium

http://vimeo.com/56606700 (Zottoli) (Netrium X400)

http://vimeo.com/86533663 (Zottoli) (Netrium)

c. Roya

 

http://vimeo.com/86533662 (Zottoli) (Roya and Spirotaenia)

d. Spirotaenia

http://vimeo.com/86533662 (Zottoli) (Spirotaenia and Roya X400)

http://vimeo.com/56606701 (Zottoli) (Roya and Spirotaenia X400)

e. Staurastrum spp.

3. Diatoms

http://en.wikipedia.org/wiki/diatom

Diatoms belong to the Bacillariophyceae, a division of the Chrysophyta. The cell is protected by a cell wall (Frustule) impregnated with silicon (Silicon Dioxide). The frustule is made up of two halves (Valves) that fit together like the top and bottom of a shoe box. The valves are often adorned with fine lines . In addition to the photosynthetic pigments chlorophyll a and b, they have a golden brown pigment that gives them their characteristic color. There were a number of small diatoms that I was unable to name so that the number of genera reported here is not necessarily indicative of the diversity of this group at the HVNC bog.

 

http://vimeo.com/86551441 Zottoli) ((Cocconeis)

http://vimeo.com/86564565 (Zottoli) (Frustulia)

http://vimeo.com/86553617 (Zottoli) (Navicula)

http://vimeo.com/86553616 (Zottoli) (Pinnularia)