The chromosomal genome sequence of the mollusc, <i>Ctena decussata</i> (O.G.Costa, 1829) and its bacterial endosymbiont <i>Candidatus</i> Thiodiazotropha sp. CDECU1 (Chromatiales)

We present a genome assembly from a specimen of <i>Ctena decussata</i> (Mollusca; Bivalvia; Lucinida; Lucinidae). The genome sequence has a total length of 1,658.05 megabases. Most of the assembly (97.83%) is scaffolded into 18 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 53.28 kilobases in length. The genome of <i>Candidatus</i> Thiodiazotropha sp. CDECU1, a bacterium associated with <i>C. decussata</i> was also assembled.