Prokaryotic microbiota associated to the digestive cavity of the jellyfish Cotylorhiza tuberculata

The microbiota associated to the gastric cavity of four exemplars of the jellyfish Cotylorhiza tuberculata has been studied by means of cultured-dependent and –independent methods. The pyrosequencing approach rendered a very reduced diversity of Bacteria in where four major groups were shared by the four exemplars and made up to 95% of the total diversity. The culturing approach recovered low abundant organisms but detected by the pyrosequencing approach. The major key organisms were related to the genera Spiroplasma, Thalassospira, Tenacibaculum (from the pyrosequencing data), and Vibrio (from the cultivable fraction). Altogether the results indicate that C. tuberculata contains an autochtonous microbiota of very reduced diversity that may have established a beneficious mutualist relation with the host. On the other hand, some of the major key players may be potential pathogens and the host may serve as dispersal mechanism.