Schizoporella errata (Bryozoa, Cheilostomata) in the Mediterranean Sea: abundance, growth rate, and reproductive strategy

The cheilostome bryozoan Schizoporella errata (Waters, 1878) is reported as a wide spread species, common on natural and artificial substrates and considered to be a significant environmental bioengineer. However, available knowledge of its reproduction and growth rate is lacking. We studied its reproductive strategy and abundance in natural habitat in the Israeli Mediterranean, along with colony growth rate under different current regimes, to allow a better understanding of this species’ behaviour. A two-year survey of its reproductive state showed that the colonies of this species are simultaneous hermaphrodites, featuring both sterile and hermaphrodite zooids at various stages of the sexual cycle. The species reproduces all year long with a negative correlation between sperm production and water temperature. Experimental monitoring of the colony growth rate under different current velocities revealed a high growth rate under strong currents while in a sheltered area with almost no water movement the colonies did not grow at all. Our findings on this widely distributed species shed light on its biology, and expected to contribute to the management and planning of marine infrastructures. Additionally, they provide a basis for future research employing S. errata as a model species.