The role of bristles in the distribution of aScenedesmus(Chlorophyceae)

Grazer‐induced colony formation in Scenedesmus: are there costs to being colonial?

“…Colonies had higher sinking rates than unicells, which has also been reported by Conway and Trainor (1972). The measured sinking rates (0.07 -0.30 m d − 1 ) are in good agreement with literature data for Scenedesmus that vary from 0.07 to 1.1 m d − 1 (Titman and Kilham 1976, Burns and Rosa 1980, Trainor and Egan 1988, Visser et al 1996. The non-treated S. acutus populations consisted almost completely of unicells.…”

“…The genus Scenedesmus may be subdivided into two subgenera, Scenedesmus containing the non-spiny and Desmodesmus containing the spined species (Kessler et al 1997). Spines may be effective against small predators, whereas bristles over 100 mm long may form a net that may discourage even larger grazers (Trainor and Egan 1988). Thick cell walls and mucilage may give Scenedesmus resistance to digestion (Horn 1981, Levitan 1987.…”

Phenotypic plasticity in the green algae Desmodesmus and Scenedesmus with special reference to the induction of defensive morphology

“…Other potential defensive characteristics that may hamper ingestion are bristles and spines. Bristles of over 100 µm long may form a net that may discourage even the largest grazers (Trainor & Burg 1965c, Massalski et al 1971, Trainor & Egan 1988. Also the shorter and thicker spines may be effective against predators reducing for example Daphnia growth and reproduction (DeLange and Van Donk 1997).…”

Low cell density: the unifying principle for unicell development inScenedesmus(Chlorophyceae)

“…6 C). Bristles help to maintain the organism in suspension in the water column (Trainor & Egan, 1988). This sequence from Type II to Type I coenobia (Fig.…”

“…Determination of the presence or absence of bristles, long delicate appendages, was conducted using the techniques described in Trainor & Egan (1988). All mean cell dimensions are based on 100 cell measurements.…”