Lobocharacium is a genus of green algae in the family Characiosiphonaceae. It contains the single species Lobocharacium coloradoense. It has been isolated from a pond in Colorado, United States.
Lobocharacium coloradoense consists of individual, spindle-shaped cells that are 120–230 μm long and 50–120 μm in diameter, attached to a substrate via a small pad. Cells are multinucleate, with multiple nuclei. Surrounding each nucleus is a cone-shaped chloroplast which is stellate viewed from the front, each with a central pyrenoid. Nuclei and chloroplasts are each in their own lobe or compartment of the cytoplasm, the lobes connected by thin bridges. Contractile vacuoles are absent.[1]
Lobocharacium reproduces asexually and sexually. Asexual reproduction occurs by zoospores, which have two flagella, a stigma and a parietal with a pyrenoid. Alternatively, aplanospores may also be formed. Sexual reproduction is isogamous, with spherical gametes with two flagella. The zoospores and gametes are released when the entire cell wall dissolves.[1]
Lobocharacium is most closely related to the genus Characiosiphon,[2] and shares many morphological characters, including the multinucleate cells with many stellate chloroplasts. The latter genus produces larger cells (up to 0.5 cm), with a large central vacuole and many smaller contractile vacuoles. Additionally, the zoospores and gametes in Characiosiphon are released through a pore in the cell wall.[1]