Effect of Marine Bacteria and their Exopolymers on the Attachment of Barnacle Cypris Larvae

The effects of marine bacteria on the attachment of cypris larvae of the barnacle Balanus amphitrite were investigated in the laboratory. Initial experiments included the effect of different species of bacteria, cyprid age, and bacterial film age on cyprid attachment. Additional studies examined the substratum/bacterial film interactions and their effect on cyprid attachment, and the effect of bacterial extracellular products on larval attachment. Data indicate that: (1) microbial films can influence attachment by cypris larvae; (2) films composed of single species of bacteria can influence attachment by stimulation and inhibition; (3) attachment by older larvae continues to be inhibited by some bacteria; (4) when films of some inhibitory bacteria are aged they become even more inhibitory to larval attachment; (5) the same bacterium adsorbed on different substrata elicits different attachment responses by the larvae; and (6) bacterial exopolymers appear to be involved in the larval attachment response. The exact nature of the bacterial components involved in the larval response is unknown.