''Phyllariopsis purpurascens'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of large

brown algae Brown algae (: alga) are a large group of multicellular algae comprising the class (biology), class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate ...

, found in the

subtidal zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

of the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

and the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

, as observed by Lourenço et al. (2020). While it is functionally similar to

kelp Kelps are large brown algae or seaweeds that make up the order (biology), order Laminariales. There are about 30 different genus, genera. Despite its appearance and use of photosynthesis in chloroplasts, kelp is technically not a plant but a str ...

species, it is not in the order Laminariales. In general, this macroalgae is affected by

ultraviolet light Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of th ...

and avoids shallow waters in the sunny Mediterranean. In fact it was thought that there were no forests of large brown macroalgae, including

, in the Mediterranean, until the first was discovered by

Jacques Cousteau Jacques-Yves Cousteau, (, also , ; 11 June 191025 June 1997) was a French naval officer, oceanographer, filmmaker and author. He co-invented the first successful open-circuit self-contained underwater breathing apparatus (SCUBA), called the ...

in his research vessel ''Calypso'' in 1958. Instead the

forests A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological functio ...

grow at greater depths than in other oceans. For example, in the cold upwelling water in the Mediterranean near the

Strait of Gibraltar The Strait of Gibraltar is a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Europe from Africa. The two continents are separated by 7.7 nautical miles (14.2 kilometers, 8.9 miles) at its narrowest point. Fe ...

, where '' Saccorhiza polyschides'' occurs below , ''

Laminaria ochroleuca ''Laminaria ochroleuca'' is a large kelp, an alga in the order Laminariales.Bunker, F.StP,D., Brodie, J.A., Maggs, C.A. and Bunker, A.R. 2017. ''Seaweeds of Britain and Ireland. Second Edition.'' Wild Nature Press, Plymouth, UK. They are commonl ...

'' below , ''

Phyllariopsis brevipes ''Phyllariopsis brevipes'' is a species of large brown algae Brown algae (: alga) are a large group of multicellular algae comprising the class (biology), class Phaeophyceae. They include many seaweeds located in colder waters of the Northern ...

'' below and ''Phyllariopsis purpurascens'' below ; the two species of ''Phyllariopsis'' also form open communities on the seabed at much greater depths.

References

Tilopteridales Marine biota of Europe Plants described in 1987 {{phaeophyceae-stub