Azolla live caroliniana aquatic floating

• High in protein.
• Maintains water temperature.

Azolla (Azolla sp.) is an aquatic fern consisting of a short, branched, floating stem, bearing roots which hang down in the water. The leaves are alternately arranged, each consisting of a thick aerial dorsal lobe containing green chlorophyll and a slightly larger thin, colourless, floating ventral lobe. Under some conditions, an anthocyanin pigment gives the fern a reddish-brown colour. diameter ranges from 1-2.5 cm for small species such as Azolla pinnata, to 15 cm or more for Azolla nilotica. Azolla s are triangular or polygonal in shape, and float on the surface of the water, individually or in mats. They give the appearance of a dark green to reddish carpet, except Azolla nilotica that does not produce the red anthocyanin pigment. The most remarkable characteristic of azolla is its symbiotic relationship with the nitrogen-fixing blue-green alga (cyanobacterium) Anabaena azollae. The fern provides ents and a protective cavity in each leaf to Anabaena colonies in exchange for fixed atmospheric nitrogen and possibly other growth-promoting substances Azolla has a historical role in agriculture. For centuries, it has been recognized as a useful in Southern China and Northern Vietnam, where it has been used as a biofertilizer and green manure for the rice crop due to its N-fixing abilities Azolla was also mentioned as a poultry feed in Peru in the 18th century. Azolla production was heavily promoted in the early 1960s in China and Vietnam, resulting in a rapid expansion in these countries. It attracted international attention in the 1970s as a result of the oil crisis and the rising prices of fossil fuel-dependent N fertilizers. Azolla became a potential replacement for these as it was believed that it could bolster rice production in many tropical countries. However, enthusiasm for azolla faded in the 1980s and was followed by a period of scepticism. Azolla production in China and Vietnam declined (perhaps due to the increasing use of land for