Planktolyngbya limnetica is a species of cyanobacteria characterized by unbranched, straight or slightly curved filaments composed of a single row of narrow trichomes, typically 0.5 to 1.5 micrometers in diameter, without a distinct sheath. The cylindrical to slightly barrel-shaped cells are uniform in length and width. This species lacks specialized cells such as heterocysts and akinetes. Its pigmentation, which includes chlorophyll a, phycocyanin, and allophycocyanin, gives it a distinctive blue-green color. Found in freshwater environments like lakes and ponds, Planktolyngbya limnetica is planktonic and reproduces through binary fission and filament fragmentation. Under the microscope, it appears as fine, hair-like structures due to its thin trichomes and uniform cell structure.