The effect of bacterial films on the temporary adhesion and permanent fixation of cypris larvae, balanus amphitrite darwin

The relative tenacity of temporary adhesion of cypris larvae of the barnacle Balanus amphitrile Darwin was measured on three substrata (polystyrene, tissue‐culture polystyrene, and glass) with and without the presence of films of the marine bacterium Deleya marina (ATCC 25374). Cyprids that were day 0 (day of metamorphosis from the sixth stage nauplius) or day 2 (two days later) were used in the experiments. Concomitant with these measurements, fixation assays (22 h) were conducted on the same filmed and unfilmed substrata. Results indicate that although the three unfilmed substrata varied in their wettability, this had no apparent effect upon the tenacity of temporary adhesion. In addition, in contrast to reports for Balanus (= Semibalanus) balanoides (L.) there was no correlation between the tenacity of temporary adhesion and fixation to unfilmed substrata of these cyprids. The presence of bacterial films (cells and their extracellular polymers) resulted in (1) similar wettabilities for the three substrata, (2) varying effects on the tenacity of temporary adhesion for day 0 cyprids, and (3) similar effects on the tenacity of temporary adhesion for day 2 cyprids. No correlation was observed between the tenacity of temporary adhesion and fixation of cyprids to bacterial films on the three substrata. Bacterial film inhibition of fixation is hypothesized to be through cyprid chemoreceptors.

Key words:

• bacterial films
• barnacles
• temporary adhesion
• fixation