General Characteristics:

Chlorophyta is the most diverse division of algae containing about 7500 species. Chlorophyll a and b coupled with the lack of other pigments give most Chlorophyta their green color. Green algae may be unicellular or multicellular. They may also be coenocytic (one big cell without walls), and uninucleate or multinucleate. All green algae have at least one plastid and carotenoids. Flagella may be absent or many. (Moore, 1998.)

Morphology: Bright green color. Blade-like thallus.

Structure: Blades are two cell layers thick. Tissue does not exhibit cellular differentiation. One nucleus and chloroplast per cell = uninucleate cells

Reproduction: Alternation of generations.

Distribution: World-wide. On the Pacific coast it is found from Alaska to Chile. U. lactuca is found on rocks in upper intertidal zones. It is also found free floating in calm waters. It is prevalent on the shores of the Sea of Cortez. We found it free floating in the calm bays of Espiritu de Santo.

The genus Caulerpa contains over 70 species.
These are differentiated by shoot structure which varies from leaf-like to radiately or bilatterally symmetric. This genus is noted for a structure that is analogous to plants.

Morphology: Green color. Plant-like appearance.

Structure: Horizontal system with vertical shoots. Caulerpa sp. has uniaxial, multinucleate siphonous ulvophyceans. (Graham and Wilcox, 2000)

Distribution: Caulerpa is found in tropical and subtropical climates in sand and mud bottoms up to 15m deep. Interestingly, the height of C. mexicana varies depending on wave action. The greater the waves, the shorter this species will grow. In calm areas it exhibits long blades(15-20cm), in wave intensive areas the blades become shorter (2cm tall). (Littler et al, 1989)

General Characteristics:

There are approximately 3900 species of red algae. They typically contain chlorophylls a and d, carotenoids, phycobilins and xanthophylls. (Moore, 1998.) Their red color is due to the presence of phycoerythrin, which reflects red and absorbs blue. Since the short wavelength of blue light can penetrate deeper than red or green underwater, red algae can thrive at greater depths. A group of red algae called coralline algae precipitate calcium carbonate, forming coral-like protection. This is observed mainly in warmer waters because calcium carbonate is less soluble at higher temperatures. It is thought that this calcification is an evolutionary tactic to evade predation. All Rhodophyta lack flagella. (Graham and Wilcox, 2000.)

Common Name: "Tukish towel"

Morphology: Deep red to purple red in color. May have bluish tint underwater. Large blade (30-50 cm long by 10-20 cm wide) whole or divided. Rough papillae cover the female gametocytes giving the blade a "terry-cloth" texture. Multiaxial. (Waaland, 1977.)

Reproduction: Gigartina sp. produce tetrasporophytes, crustose thalli that were previously thought to be a separate species called Petrocelis sp. (Graham and Wilcox, 2000.)

Distribution: British Columbia to California. Lower intertidal to subtidal, 5-10m deep. Grows on rocky substrate. (Waaland, 1977.)

Morphology: Uniaxial, radially branched, polysiphonious and filamentous. With globular cystocarps. (Abbott and Hollenberg, 1976.) Tufts and plumes up to 15 cm long. (Waaland, 1977.) Reddish brown in color.

Reproduction: Asexual and sexual

Distribution: British Columbia to Baja,
California. Low intertidal to tidal on rocks or
other algae.

The popular edible nori seaweed is from the genus Porphyra.
Porphyra described.

Morphology: Blades are ruffled, two cell layers thick and usually the same in width and length. Rhizoidal cells attach blades to the substrate. (Graham and Wilcox, 2000.)

Reproduction: Alternation of generations, gametophyte (blade) vs. microthallus phase. (Graham and Wilcox, 2000.)

Distribution: Alaska to Baja. Rocky shores in intertidal and subtidal zones. (Waaland, 1977.)

General characteristics:

Phaeophyta contains approximately 1500 species. Of these all are multicellular, branched, non-colony formers, and non-filamentous. Most produce motile diflagellate cells. They contain chlorophylls a and c, fucoxanthin, and other carotenoids. (Moore, 1998.)

Common Name: Giant Kelp

Morphology: HUGE and BEAUTIFUL. Up to 60m tall. Thallus has branched stipe, and multiple blades and floats. Each blade has own float. (Graham and Wilcox, 2000.)

Distribution: Northern Pacific coast. M. pyrifera thrives in cold water on rocky substrates or course sand. Water above 22°C is intolerable. (Graham and Wilcox, 2000.) It is found on the Pacific coast of Northern Baja, California because of local upwelling of cold water. We saw it just south of Ensenada.

Reproduction: Female gametophytes are unicellular whereas male gametophytes are multicellular. (Graham and Wilcox, 2000)

Morphology: Main axis is cylindrical with leaf-like blades and air bladders. (Graham and Wilcox, 2000.) Can be free floating. Like M. pyrifera, Sargassum can protect many marine organisms from unfavorable coditions like high wave activity and predation.

Distribution: World-wide. U.S. Pacific coast, south to Baja. Temperate to tropical waters.