What is algae?

Algae are simple organisms that typically produce their own food through photosynthesis. They are similar to higher plants, but they lack many of the distinct organs that you will find in a higher plant. The higher plants are believed to have evolved from algae, and algae are believed to have gotten their capacity for photosynthesis from cyanobacteria.

Some types of algae are capable of absorbing organic carbon through osmotrophy, myzotrophy or phagotrophy and are therefore not forced to rely solely on photosynthesis. Osmotrophy is a process where dissolved organic compounds are absorbed through osmosis. Myzocytosis is a method (sometimes referred to as “cellular vampirism”) by which the algae will suck out cellular content from other cells through a feeding tube. An alga that carries out phagocytosis will engulf solid particles with its cell membrane to form an internal food vacuole.

Algae can be unicellular as well as multicellular. Large and complex forms found in the ocean are commonly referred to as seaweed and can look very similar to higher plants. Algae are voluntarily and involuntarily kept by many aquarists. Some species are very beautiful and well-liked, while others are shunned and meticulously exterminated from the aquarium. There are also many types of algae that can help you keep the water quality up in the aquarium by binding substances known to be harmful to fish and other aquatic animals and exude oxygen in exchange. Algae can turn the aquarium into a better functioning ecosystem and allow the animals to carry out more of their natural behaviours in captivity.

Algae are not only something encountered by aquarists and pond keepers; they can occur in virtually all moist environments including swimming pools and bathrooms. Certain types of algae are also appreciated as food throughout the world.