Branching bryozoan

Appearance

Typically dark brick red with orange-red growing margins. This species may form heavy knobbly encrustations on flexible surfaces such as algae or worm tubes, turning them into solid, sometimes erect branching structures. The thickness of the growth is dependent upon the age of the colony. Multilaminar encrustations of 1cm thick are common. The frontal surface of the zoecium (secreted exoskeleton housing of individual zooids) is porous with a wide semicircular aperture and proximal sinus. avicularia (beak-like structures) occur in varying density on colonies, located (one per zooid) to the right or left side of aperture sinus. Bleached specimens show the skeletal features clearly. Preserved specimens lose their colour. S. errata forms massive colonies with variously shaped colony forms. Forms are determined by interactions with other organisms and hydrodynamic conditions. At exposed sites, colonies form a densely packed mass with no branching, while in calmer waters colonies are erect, highly branched and have thicker bases

This bryozoan has a unilamellar or multilamellar encrusting base (maximum thickness of around 1 cm) more or less extensive (up to 40 cm in diameter) and from which leafy, branched, cone-shaped expansions can be erected. cylindrical or simply massive. The shape of these bioconstructions is directly linked to local hydrodynamics and the interaction with other organisms occupying the nearby substrate, the fragile and leafy forms only existing in calm areas (port, coastal ponds) where they can reach large sizes (relief of the order of 10 to 25 cm in height) and form sediment traps when the horns are open upwards. The lighter growing areas on the periphery of the colony are often orange-brown while the center shows a very dark, purplish-brown-black color. The underside of the blades is clear, this being observed at the level of the horns present on the leafy forms.
The lophophores are light beige.

Distribution

Mediterranean, Northwest Atlantic, Indo-Pacific, Red Sea, Caribbean.

Habitat

It is a shallow species (0.5 to 20 m) preferring calm waters loaded with organic matter. It attaches to all hard and free substrates, such as rocks, mussels, the tubes of certain worms and more particularly port infrastructure and boats, as well as to algae and in mangroves.

Reproduction

Like all bryozoans, this species is capable of sexual reproduction. Fertilized eggs are released in the form of larvae. The swimming larva settle into a substrate and generate a new colony by asexual division. Asexual multiplication can also occur from a broken fragment or by cleavage of the colony.

Food

Microphagous filter feeder. Diatoms are the basis of the diet of bryozoans. The cilia of the tentacles are capable of creating microcurrents allowing the transport of food particles towards the mouth in the center of the lophophore (which also works as organ for respiration and cleaning of the colony).