Phylogenetic characterisation of bacterial symbionts in the accessory nidamental glands of the sepioid Sepia officinalis (Cephalopoda : Decapoda)

Female cuttlefish harbour a dense bacterial community in their accessory ni damental glands (ANG), as is also the case for the myopsid squids. Molecula r approaches have been applied to explore this symbiotic association in the sepiid species Sepia officinalis. In situ localisation by Bacteria-specifi c probes in tissue sections of the ANG revealed the presence of a dense bac terial population in the lumina of the organ tubules. The phylogenetic iden tification of bacterial strains was realised by 16S rRNA gene sequencing an alysis. None of the sequences obtained matched perfectly with known sequenc es in the database. However their similarity percentages allowed us to rela te them to various bacterial groups including the taxa Agrobacterium, Roseo bacter, Sporichthya, Rhodobium-Xanthobacter and Clostridium. Some bacterial species are common to both sepioids and myopsid teuthoids, others are diff erent.