Keppostella

Keppostella is a genus of unicellular, photosynthetic protists commonly found in coastal marine and brackish waters. Descriptions of the genus began in the mid-2010s when researchers named Kepp and Stella formally characterized its features and placed it among the stramenopile microalgae. The genus includes several species that populate surface waters from temperate estuaries to tropical lagoons.

Cells of Keppostella are small, typically 6–15 micrometers in length, and range from oval to elongated in shape. The cell wall is often described as silica-like, with a patterned surface that may include perforations. Each cell bears two flagella of unequal length, which propel the organism and help maintain position within phytoplankton communities. Chloroplasts enable photosynthesis, giving the cells a light to olive-green hue under microscopy.

Keppostella contributes to primary production in its habitats and forms part of coastal food webs, serving as prey for microzooplankton and small filter feeders. Populations can bloom when light and nutrient conditions are favorable, while declines occur with nutrient depletion or unfavorable environmental changes. Reproduction is primarily asexual through binary fission; under stress, resting or cyst-like stages may form to endure adverse conditions. Sexual reproduction, if it occurs, has not been definitively observed in described species.

Taxonomically, Keppostella is recognized as a distinct genus within coastal phytoplankton communities. The genus name is said to originate from the surnames of its describers. As of current reviews, multiple species have been assigned to Keppostella, reflecting a modest but detectable component of microphytoplankton diversity. Ongoing molecular studies aim to resolve interspecific relationships and biogeographic patterns.