Effect of the biofilm of two native bacterial strains on the settlement of Argopecten purpuratus larvae

The aim of this study was to isolate, select and genetically characterize native Argopecten purpuratus bacteria that, through a biofilm, stimulate their larval settlement. Knowing that larval settlement is the main problem faced by the laboratory reproduction of this mollusk, a bacterial biofilm was used to improve the larval fixation percentage. Native bacterial strains were isolated from the A. purpuratus culture and taxonomically characterized from the analysis of the partial sequences of the 16S rRNA gene, amplified by PCR to each of the DNA samples extracted from the isolated bacterial strains. When analyzing the sequences, three bacterial strains were identified at the genus level: Oceanobacillus, Bacillus, and Pseudomonas. In addition, the fixation efficiency of A. purpuratus larvae was evaluated in the biofilms formed by the Oceanobacillus and Bacillus strains, achieving a fixation of 12 and 14%, while being associated was 37%. It is concluded that the larval fixation of A. purpuratus improves with the bacterial biofilm composed of Oceanobacillus and Bacillus, compared to the control, without the use of bacteria.