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General Overview
chlorophyTa
Members of this phylum are common inhabitants of marine, freshwater, and terrestrial environments; within the phylum, a great range of somatic differentiation occurs, ranging from flagellates
to complex multicellular thalli differentiated into macroscopic organs. The different level of thallus
organization (unicellular, colonial, filamentous, siphonous, and parenchimatous) has traditionally
served as the basis of classification of this division. Chlorophytes show a wide diversity in the number and arrangements of flagella associated with individual cells (one or up to eight, in the apical
or subapical region). All members of the chlorophytes have motile stages with two or four anterior
isokont flagella (i.e., flagella are of equal length and possess equivalent function), although algae
with two flagella of slightly unequal lengths have been described. Flagella are characterized by a
“stellate structure”-type flagellar transition region. Within the cell, the flagellar basal bodies are
associated with four microtubular rootlets, cruciately arranged, which alternate between two and
FIGURE 1.37 A group of eight autospores of Glaucocystis nostochinearum still retained within the parent
cell wall. Scale bar: 10 μm.
FIGURE 1.38 Frond of Rhodophyllis acanthocarpa. Scale bar: 5 cm.
General Overview
chlorophyTa
Members of this phylum are common inhabitants of marine, freshwater, and terrestrial environments; within the phylum, a great range of somatic differentiation occurs, ranging from flagellates
to complex multicellular thalli differentiated into macroscopic organs. The different level of thallus
organization (unicellular, colonial, filamentous, siphonous, and parenchimatous) has traditionally
served as the basis of classification of this division. Chlorophytes show a wide diversity in the number and arrangements of flagella associated with individual cells (one or up to eight, in the apical
or subapical region). All members of the chlorophytes have motile stages with two or four anterior
isokont flagella (i.e., flagella are of equal length and possess equivalent function), although algae
with two flagella of slightly unequal lengths have been described. Flagella are characterized by a
“stellate structure”-type flagellar transition region. Within the cell, the flagellar basal bodies are
associated with four microtubular rootlets, cruciately arranged, which alternate between two and
FIGURE 1.37 A group of eight autospores of Glaucocystis nostochinearum still retained within the parent
cell wall. Scale bar: 10 μm.
FIGURE 1.38 Frond of Rhodophyllis acanthocarpa. Scale bar: 5 cm.