Description of Yamagishiella
provided by BioPedia
Colonies cylindrical, ellipsoidal or nearly spherical, with (8), 16 or 32 cells, separated from each other by spaces and arranged peripherally in distinct tiers within a common gelatinous matrix; colonial boundary not penetrating between cells into centre of colony, each cell surrounded tightly by separate fibrillar zone (cellular envelope) of extracellular matrix within tripartite colonial boundary; cells ovoid to spherical, with two equal flagella; chloroplast cup-shaped, longitudinally striated, with a single basal pyrenoid; eyespot present, larger in anterior cells; nucleus central; contractile vacuoles 2; asexual reproduction with a plakeal stage and inversion to form daughter colonies within transparent vesicles in the parental gelatinous matrix; sexual reproduction isogamous, heterothallic; each cell of a colony potentially becoming a gamete; nutrition possibly obligately phototrophic; growing in freshwater pools and ditches, also appearing in cultures from dried soil samples.
