Water temperature and photo period are manipulated on in vitro maintained adult L. conchilega, to assess which combination of values is most optimal for spawning induction. Secondly, multiple artificial substrate structures have been provided to in vitro maintained aulophore larvae to assess which type of surface structure is preferred as a holdfast during benthic settlement. Using sand masons gathered at the start of April, in vitro gamete shedding was manifested twice using different protocols, firstly by inducing a temperature shock according to Heimler (1981) and secondly in the designed rearing system for sand masons discussed below. Fertilisation occurred, resulting in larval maintenance in the collection tank up to the trochophore stage. Aulophores were sampled by plankton hauling and in vitro maintained. The experiments revealed a clear preference for substrate B (B6000 fine mazed textile) during settlement of the aulophores, with 93,75%±6,25 of the settled juveniles retrieved from section B during the second trial. Practical experience on germ cell maturation, spawning induction of adults, larval rearing and benthic settlement of aulophores is discussed.
Managing Thesis and Internship Exchanges
