Sea Tube

Appearance

The thallus is dark green in color.
It is formed of vesicles in tight colonies or utricles. The vesicles are elongated and branched.
Their size is one to four centimeters high and one to five millimeters in diameter. Several vesicles can be attached on the same base. The thalli form a dense grass with intertwined utricles.

Distribution

Present throughout the North Atlantic. To the East: in the Azores, the Canaries and near the Portuguese coast. To the west: in the Caribbean. It is also present in the Mediterranean as well as in the Indo-Pacific.

Habitat

Usually appears in shaded areas at the upper part of the intertidal zone, sometimes in the upper regions of potholes on the abrasion platform, and sometimes in the upper regions of a cliff facing the sea in an area not exposed to low tide.

Reproduction

By budding or vegetative propagation. The vesicles can differentiate into zoidocysts where the future zoids (flagellate cells) will be formed.

Food

This algae is autotrophic photosynthetic: it develops its organic matter from carbon dioxide, minerals and light, thanks to pigments which allow it to carry out photosynthesis.