Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram.

Records were identified using ‘Scopus’, ‘Science Direct’ and ‘Web of Knowledge’. Additional records were identified from citations within the papers identified by the database searches. All records were screened and the articles addressing the maternal-embryonic relationship of sharks were assessed for eligibility. Articles reporting mass change values throughout embryonic development of sharks were included in the qualitative synthesis. Articles reporting mass change values for fishes and rays were excluded, along with studies referring to alternative aspects of shark reproductive biology.