Ulvophyceae exhibit a wide diversity of life cycles. Species may reproduce asexually, sexually, or exhibit a combination of sexual and asexual reproduction. Sexual reproduction involves a heteromorphic or isomorphic diplohaplontic life cycle, or a haplontic life cycle (Fig. 4). Gametes are either isogamous or anisogamous. Diplohaplontic life cycles are almost exclusively found in marine Ulvophyceae, while haplontic life cycles occur both in marine and freshwater taxa. An example of an isomorphic, diplohaplontic life cycle, as found in Ulva sp. (Ulvales) is illustrated in Fig. 4a, and an example of a haplontic life cycle, as found in Ulothrix (Ulotrichales), is illustrated in Fig. 4b.
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