pennatediatomeihin
Pennated diatoms are a specific morphological group within the Bacillariophyceae, a class of single-celled algae commonly known as diatoms. The term "pennate" refers to their characteristic elongated, boat-shaped or lanceolate frustules (cell walls) which are bilaterally symmetrical along one axis. Unlike centric diatoms which exhibit radial symmetry, pennate diatoms possess a distinct line of symmetry running longitudinally. A key feature distinguishing many pennate diatoms is the presence of a raphe, a slit-like or pore-like structure within the valve. The raphe allows these diatoms to glide and move along substrates by secreting a mucilage. Pennate diatoms are found in a wide variety of aquatic environments, including freshwater, marine, and even terrestrial habitats, often colonizing surfaces. They play significant roles in aquatic ecosystems, contributing to primary production and forming the base of food webs. Their intricate and diverse frustule structures are often used in diatom taxonomy for species identification.