||it is widespread all over the world.
||it is a green seaweed, consisting of inflated,
tubular fronds that grow from a small discoid base. Fronds are typically
unbranched, they may be 10-30 centimeters long or even longer and 6-18 millimeters
in diameter, usually with rounded tips. It is a summer annual plant, forming
masses of bleached white fronds towards the end of the season. It may grow
up to 1 meter in height, at the speed of 0.15 -0.25 centimeters per day.
It is euryhaline: it tolerates wide ranges in the salinity.
||it may become detached from the substratum
and rise to the water surface, where it continues to grow in floating masses.
It reproduces with an alternation of generations: a generation reproduces
by vegetative propagation (by transversal scission), the following one by
spores. It is an opportunist plant growing and spreading rapidly thanks
to the fact that it can reproduce all year round, even if the most favourable
season is summer. Its life cycle has an alternation between haploid and
diploid generations, which are morphologically the same. The cycle may change
depending on the environmental conditions. It is sensitive to the loss of
substratum sediments and to the disturbs of the bottom such as dredging.
It is an important food source for some "grazing" organisms such
as the Littorina littorea.
||it occurs in a wide range of habitats at all
shore levels. Where the substratum is suitable it will grow on rocks, mud,
sand. It is abundant in brackish water areas, where there is appreciable
fresh water run and in wet areas of the splash zone. It is also a common
epiphyte on other algae and shells.