In this thesis I will discuss three projects aimed to explore different aspects of bioluminescence and genetics in marine animals. The first project describes a series of experiments on the chemistry in the novel bioluminescent system of the marine worms of the genus Tomopteris. These luminous worms release glowing exudate when agitated, and this exudate was rich in a fluorescent pigment. The structure was determined to be an anthraquinone and the possible origins and chemical roles are discussed. The second part examines some technical aspects of transcriptome assembly and analysis for invertebrates, including many bioluminescent species. Because information content is theoretically finite yet noise from sequencing errors is introduced continuously, the optimal balance of sequencing depth is experimentally addressed and described with analysis strategies. The final part presents a detailed gene analysis of a group of putative oxidase genes which are strongly conserved across a group of luminous ctenophores and absent in genomes and transcriptomes of non-luminous ctenophores. This class of oxidases is known for its functional diversity in bacteria and fungi, and their occurrence and roles in ctenophores are discussed with relevance to bioluminescence.