Cyanobacteria

Cyanobacteria, Microalgae and Macroalgae Review

Slide 1 Anabaena	Micrograph of Anabaena at 200X magnification. Note the heterocyst which functions as the site for nitrogen fixation.
Slide 2 Nostoc	Micrograph of Nostoc at 200X magnification. Note the heterocyst which functions as the site for nitrogen fixation.
Slide 3 Nostoc Living Specimen	Under Construction
Slide 4 Gloeocapsa	Micrograph of Gloeocapsa at 1,000X magnification. Note the gelatanous matrix around the cells and that Gloeocapsa normally exist as colonies of two to four cells.
Slide 5 Oscillatoria	Micrograph of Oscillatoria at 200X magnification. Oscillatoria is a filamentous species. Each of the individual cells is very thin and the filament is much like a stack of coins with coins representing individual cells.
Slide 6 Bacillariophyta - Diatoms	Micrograph of fresh water diatoms at 200X magnification. On the left we have a display slide showing various species while on the right is a typical slide of fresh water diatoms. Note that the cell walls of diatoms contain silica.
Slide 7 Bacillariophyta - Marine Diatoms	Micrograph of fresh water diatoms at 200X magnification.
Slide 8 Dinoflagellata - Peridinium	Micrograph of the dinoflagellate, Peridinium, at 400X magnification. Dinoflagellates are major elements of the phytoplankton. They have cell walls composed of plates of cellulose. Note the visible transverse groove in the cell wall.
Slide 9 Dinoflagellata - Ceratium	Micrograph of the dinoflagellate, Ceratium, at 400X magnification. Dinoflagellates are major elements of the phytoplankton.
Slide 10 Chlorophyta - Chlamydomonas	Micrograph of the green alga, Chlamydomonas, at 1,000X magnification. Even though is may not be visible in this slide, Chlamydomonas is unicellular and has two flagella
Slide 11 Chlorophyta - Oedogonium	Micrograph of the green alga, Oedogonium, at 200X magnification. Identify the oogonium and antheridial cells.
Slide 12 Chlorophyta - Oedogonium	Micrograph of the green alga, Oedogonium, at 1,000X magnification. Identify the holdfast which is used for attachment to the filament to the substrate.
Slide 13 Chlorophyta - Spirogyra	Micrograph of the green alga, Spirogyra., at 200X magnification. Note the spiraled, ribbon-like chloroplast. Spirogyra reproduces sexually to produce resistant spores. In sexual reproduction the contents of one cell becomes an amoeboid gamete and crawl through a conjugation tube into another cell where the contents fuse forming a zygospore.
Slide 14 Chlorophyta - Spirogyra	Micrograph of the green alga, Spirogyra., at 200X magnification. Note the well developed zygospores.
Slide 15 Chlorophyta - Volvox	Micrograph of the green alga, Volvox, at 100X magnification. Note that Volvox is a spherical colony of 100's to 1,000's of individual cells.
Slide 16 Chlorophyta - Ulva	Ulva is a multicellular green alga that is common along rocky marine shores around much of the world.
Slide 17 Charophyta - Chara	The Charaphyta are very similar to the Chlorophyta except that they are probably very near the line of evolution that gave rise to terrestrial plants. Chara is multicellular and produces multicellular sex organs with a sterile jacket of cells surrounding the gametes. Identify the oogonium and antheridium.
Slide 18 Phaeophyta - Sargassum and Padina	Pressed specimens of the brown alga, Sargassum and Padina. Sargassum is commonly found floating in the tropical North Atlantic and Gulf of Mexico. Other species of Sargassum are found growing attached to tropical rocky shores. Padina is found through out the tropics and subtropics. It forms flat multicellualr sheets with deposits of calcium carbonate.
Slide 19 Rhodophyta - Hypnea and Pterocladia	Pressed specimens of the red algae, Hypnea and Pterocladia. Both genera are found along the Texas Gulf Coast and in Hawaii.
Slide 20 Rhodophyta - Calcareous Red Alga	A specimen of a calcareous red alga. Calcareous algae are important in the deposition of calcium carbonate in reef and coastal environments in much of the marine world.