Bacteria associated with mass mortality of post-larvae of red conger eel (Genypterus chilensis) cultured in a Chilean farm

The red conger eel (Genypterus chilensis, Guichenot) is an alternative for aquaculture diversification in Chile. However, improvements in sanitation are still necessary for success in new aquaculture programs and farm production. The present study was aimed to identify and characterize 21 bacteria associated with a massive mortality of weak post-larvae reared in a Chilean nursery. Phenotypic tests and sequencing of the 16S rRNA gene allocated the isolates predominantly within the genus Vibrio, including species previously associated with disease in farmed fish such as V. anguillarum, V. ordalii and V. tapetis, as well as another described from healthy clams such as V. toranzoniae. Despite this, other genera such as Pseudoalteromonas, Psychrobacter, Alteromomas, Marinobacter, Planococcus and Pseudomonas were also identified. Some bacterial isolates showed pathogenic potential, however, further studies are necessary to clarify whether these bacteria belong to the autochthonous microbiota of this fish species or are potential pathogens.