Laboratory culture and evaluation of the tubeworm Ficopomatus enigmaticus for biofouling studies

Ficopomatus enigmaticus, a euryhaline tube-building polychaete worm with a subtropical to temperate distribution, is an increasingly problematic fouling organism. In this study, laboratory protocols for maintaining adult broodstock, destructive spawning, larval culture and a settlement bioassay were developed. The method routinely yielded approximately 200 larvae per spawning adult. The mean number of eggs released by females was 1517 and the mean number of spermatozoids per male was 4.425x10(6). Fertilisation success, using an initial concentration of 2.5x10(6) spermatozoids and 45eggsml(-1), was 76% after a contact time of 60min. The first cleavage occurred after 20min and the trocophore larval stage was attained by 18h. Metatrochophores were observed 4d post-fertilisation and were competent to settle 1day later. The proportion of larvae that settled after 48h was surface-dependent: 10.24% on glass, 1.39% on polystyrene and 11.07% on a poly(dimethylsiloxane) elastomer. The presence of a biofilm on glass increased the rate of settlement 7-fold compared to clean glass.