Red algae

at Stångehuvud

To algae in the shore zone

To rock shores

Red algae are growing from the surface and several tens of meters down. These species use the wavelengths of light that reaches far down in the water. They absorb green light and reflect the reddish.

Polysiphonia
This species is up to a couple of decimeters long. This annual red algae may grow down to about 20 meters depth. The genus is often seen even in the superficial layers of water and grows on rocks and stones, but also on coarser algae as knotted wrack and bladder wrack. Typical of Polysiphonia are the very finely branched, heavy dark red shoots. Several related species difficult to determine occur within the genus.

Polysiphonia often grows on other coarser algae near the surface. Here it is seen on knotted wrack and bladder wrack.