Sphaeropleales

Portrait of the planktonic unicellular chlorellacean alga, Tetraedron trigonum(Nägeli) Hansgirg. The cell body is flat and triangular. The corners are drawn out as straight or slightly curved spines. There are multiple discoid plastids.Collected from a freshwater pond near Boise, Idaho.July 2005. DIC.

Portrait of the planktonic unicellular chlorellacean alga, Tetraedron trigonum (Nägeli) Hansgirg. The cell body is flat and triangular. The corners are drawn out as straight or slightly curved spines. There are multiple discoid plastids.Collected from a freshwater pond near Boise, Idaho.July 2005. DIC.

A common planktonic Chlorophyte (Chlorococcales).

Portrait of Pediastrum duplex (Meyen, 1829 ).Collected from a freshwater pond near Boise, Idaho. Phase contrast.

Portrait of Pediastrum duplex (Meyen, 1829 )demonstrating tufts of bristles protruding from the notch at the ends of the horns of peripheral cells (seen most clearly at one o'clock and 7 o'clock here). These bristles are thought to consist of proteinaceous microfilaments (see Scnepf,E. et al. J. Ultrastruct. Res. 72:367-379,1980). These nonmotile bristles may play a role in orienting the coenobia in the water column . DIC.

Pediastrum duplex is a common chlorophyte (Chlorococcales) of Lake Kinneret, relatively more abundant in winter, especially in “No-Peridinium years”. This specimen was collected at the shore by the Kinneret Limnological Laboratory in June 2006

Portrait of a colony Scenedesmus falcatus (Chodat, 1894). Phase contrast.

Portion of a coenobium of the chlorophycean, Hydrodictyon reticulatum (Lagerheim, 1894.The tubular coenobia have walls composed of a meshwork of cells whose interspaces are bordered by 5 or 6 cells (five in this case). Coenobia may form nets up to 2 feet in length.The cylindrical cells are uninucleate when toung and become multinucleate as they age. the plastid is peripheral and reticulate in older cells. there are many pyrenoids. Biflagellate zoospores released within the mother cell wall may may aggregate to form a mini meshwork that is ultimately released as a new coenobium.Collected from a temporary freshwater pond near Boise, Idaho. August 2005. Brightfield.

Portion of a coenobium of the chlorophycean, Hydrodictyon reticulatum (Lagerheim, 1894.The tubular coenobia have walls composed of a meshwork of cells whose interspaces are bordered by 5 or 6 cells (five in this case). Coenobia may form nets up to 2 feet in length.The cylindrical cells are uninucleate when toung and become multinucleate as they age. the plastid is peripheral and reticulate in older cells. there are many pyrenoids. Biflagellate zoospores released within the mother cell wall may may aggregate to form a mini meshwork that is ultimately released as a new coenobium.Collected from a temporary freshwater pond near Boise, Idaho. August 2005. Brightfield.

Detail of the junction of three cells of a coenobium of the chlorophycean, Hydrodictyon reticulatum (Lagerheim, 1894.The tubular coenobia have walls composed of a meshwork of cells whose interspaces are bordered by 5 or 6 cells (five in this case). Coenobia may form nets up to 2 feet in length.The cylindrical cells are uninucleate when toung and become multinucleate as they age. the plastid is peripheral and reticulate in older cells. there are many pyrenoids (seen here). Biflagellate zoospores released within the mother cell wall may may aggregate to form a mini meshwork that is ultimately released as a new coenobium.Collected from a temporary freshwater pond near Boise, Idaho. August 2005.DIC.

Coelastrum astroideum (De Notaris 1867). Collected from freshwater aquaculture tub near Boise, Idaho December 2005. Brightfield.

Coelastrum astroideum (De Notaris 1867). Collected from freshwater aquaculture tub near Boise, Idaho December 2005.

A rare variety of Pediastrum duplex in Lake Kinneret. This specimen was collected at the shore by the Kinneret Limnological Laboratory in June 2006.

Pediastrum (pee-dee-ass-trum) a colonial green alga. cellulose cell walls, plastids with chlorophyll B, pyrenoids present. Colonies flat, and species distinguished by shape and arrangement of cells. Differential interference contrast.

Pediastrum is a large, flat desmid. Many cells join together by their cellulose walls to form a regular, star-shaped array.

Palmodictyon (palm-o-dick-tea-on) is a branching green alga in which coccoid cells are located within a mucus-like branching structure. The mucoid matrix develops a pink colour with age. The cells divide within the matrix and leave vacated cell walls behind, as this detailed micrograph shows. Differential interference contrast.

Palmodictyon (palm-o-dick-tea-on) is a branching green alga in which coccoid cells are located within a mucus-like branching structure. The mucoid matrix develops a pink colour with age. The cells divide within the matrix and leave vacated cell walls behind. Phase contrast.

Palmodictyon (palm-o-dick-tea-on) is a branching green alga in which coccoid cells are located within a mucus-like branching structure. The mucoid matrix develops a pink colour with age. The cells divide within the matrix and leave vacated cell walls behind. Filaments at low magnification. Phase contrast.

Palmodictyon (palm-o-dick-tea-on) is a branching green alga in which coccoid cells are located within a mucus-like branching structure. The mucoid matrix develops a pink colour with age. The cells divide within the matrix and leave vacated cell walls behind. Phase contrast.

Palmodictyon (palm-o-dick-tea-on) is a branching green alga in which coccoid cells are located within a mucus-like branching structure. The mucoid matrix develops a pink colour with age. The cells divide within the matrix and leave vacated cell walls behind. Detail of two filaments. Differential interference contrast.

Ankistrodesmus (anne-kissed-ro-des-muss) is a green alga, small tangled clusters of twisted cells. Four cells in this tangle. Not uncommon in freshwater habitats. Differential interference contrast.

Ankistrodesmus (anne-kissed-ro-des-muss) is a green alga, small tangled clusters of twisted cells. Two tangles seen here making a spectacle of themselves. Not uncommon in freshwater habitats. Phase contrast.

Ankistrodesmus (anne-kissed-ro-des-muss) is a green alga, small tangled clusters of twisted cells. Two tangles seen here Not uncommon in freshwater habitats. Phase contrast.

Ankistrodesmus (anne-kissed-ro-des-muss) is a green alga, often forming small tangled clusters of twisted cells. Four cells in this tangle. Not uncommon in freshwater habitats. Differential interference contrast.