Yesterday (19.2.) 10 adults and one juvenile ("Alice") noble pen shell (Pinna nobilis) from the Venetian lagoon arrived in our aquarium.
We placed the individuals in new holding pools with seawater that has been purified and continuously treated with UV light and filtered to 1 micrometer and with the appropriate temperature (12°) and salinity (34؉). They feed on a variety of phytoplankton (Tetraselmis suecica, Phaeodactylum tricornutum, Isochrysis galbana, Tisochrysis lutea) and zooplankton (rotifers). Little is known about their life cycle,
given that the noble pen shell is a protected and non-commercial species that has not been cultivated before.
Only recently, when it became a critically endangered species, some institutions have tried to cultivate it under controlled conditions. Still, so far no one has succeeded in completing their life cycle. It is known that the noble pen shell, like some other bivalves, is hermaphrodite, and to prevent self-fertilization, male and female gametes are not produced at the same time (asynchronous development of gametes). Noble pen shell reaches sexual maturity around the age of two. Spawning in nature starts with rising water temperature, most often in late spring, while the peak of spawning is in the summer months. Fertilization is external, and the larval stage is planktonic.