Synechococcus sp.

These organisms may be thermophilic or mesophilic and are typically obligate photoautotrophs that perform aerobic photosynthesis. Their small cells are cylindrical, ovoid, or rod-shaped and occur singly, in pairs, or in short chains, lacking a surrounding sheath. Cells often form irregular aggregates held together by a slime layer and reproduce through repeated binary fission in a single plane. Most species are nonmotile, while motile forms move by gliding and display positive phototaxis. Currently, 28 species of Synechococcus have been described.