Plant
Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom. The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the brown, red and green algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, and they are no longer classified as plants as defined here.
Notomithrax ursus
There is also evidence that the species of algae that the seaweed crab attaches to its body are preferred species for consumption as well, so the masking behavior of these crabs serves as food storage. The crab can eat up to 4.1% of the algae masking them when there is no food available to consume. The types of algae for masking may also be chosen based on “calorific value or content of vitamins, nitrogen, or specific nutrients such as sugars and amino acids”.