Laminaria saxatilis and Alaria esculenta. Small green and red algae and animals occur, protected under these large brown algae. When washed up on beaches, kelp flies such as Coelopa pilipes feed and breed on Fucus algae. Uses In Scotland and Norway, up until the mid-19th century, several seaweed species from Fucus and other genera were harvested, dried, burned to ash, and further processed to become "kelp", which was a type of soda ash that was less costly in Britain than the barilla imported from Spain. It has an alkali content of about 2.5%–5% that was mainly sodium carbonate (Na2CO3), used in soapmaking, glassmaking, and other industries. The purest barilla had a sodium carbonate concentration of about 30%. The seaweed was also used as fertilizer for crop land in the same areas in which it was harvested. Fucus species can also be used for thalassotherapy, along with other species such as Turkish towel (Chondracanthus exasperatus), feather boa (Egregia menziesii), and finger kelp (Laminaria digitata). In 2005, it was announced that bacteria grown on Fucus have the ability to attack and kill the MRSA superbacterium. Because of their easily accessible apolar eggs and free-floating zygotes, several Fucus species have been used as model organisms to study cell polarity, the development of growth axes, and the role of the cell wall in establishing and maintaining cell identity. Predator The seaweed fly, Coelopa frigida, together with other species of Coelopa, are known to feed, mate, and create habitats out of different species of Fucus. This is of particular notice when the Fucus is stranded on the beach and not when it is submerged under seawater. With increasing amounts of seaweed washing up on shores, there is an increasing recognition of Fucus and their close pairing with Coelopa. Taxonomy This list of species of Fucus excludes names of uncertain status: Fucus atomarius (Woodward) Bertoloni Fucus ceranoides L. – horned wrack * Fucus chalonii Feldmann Fucus cottonii M. J. Wynne & Magne *(=Fucus cottonii M.J.Wynne & Magne nom. illeg.) Fucus distichus L. * Fucus evanescens C.Agardh * Fucus furcatus Stackhouse, 1801 Fucus guiryi G. I. Zardi, K. R. Nicastro, E. A. Serrão, G. A. Pearson * Fucus gardneri P. C. Silva Fucus lagasca Clemente, 1807 Fucus mytili Nienburg Fucus nereideus Lightfoot Fucus radicans L. Bergström & L. Kautsky, 2005 Fucus serratus L. – toothed wrack * Fucus spermophorus L. Fucus spiralis L. – spiral wrack *