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.
Seaweed blenny
The seaweed blenny is a diurnal species and feeds mostly on algae. The diet also includes such invertebrates as polychaete worms, crustaceans and hydroids, which it picks off the substrate with its beak-like mouth. A male may have several females in his territory, all of which deposit their eggs in a shared nest. This is in a crevice in a rock, inside a sponge, in a mollusc shell or in a can or other piece of discarded human debris. The male guards the nest until the eggs hatch. The larvae are planktonic at first, settling on the seabed when about long.