Offspring from bottom-dwelling marine species can disperse across the open ocean to distant destinations, driving population distributions and species persistence. Yet the mechanisms that determine the pathways traveled by the larvae are largely unknown. Because of challenges tied to the continuous tracking of larval movements in the open ocean, Daniel Ottmann et al. (pp. 14067–14072) measured the relatedness of more than 500 juvenile splitnose rockfish (Sebastes diploproa) to study whether individuals that had settled simultaneously to a nearshore habitat along the central Oregon coast were siblings that remained together during dispersal. Splitnose rockfish are live-bearing fish that spend up to a year in the open ocean as larvae and juveniles before settling along the US Pacific Northwest coast. The authors found that more than 11% A 4-cm-long ancient maize cob dating 5,300 years ago. Image courtesy of Jaime Padilla (Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico). Newly recruited splitnose rockfish. of new recruits to the area were siblings, suggesting that the young fish remained in a cohesive group throughout their larval and juvenile periods in the open ocean. According to the authors, understanding the dispersal of fish could improve population models and aid conservation of marine organisms across genetic and geopolitical boundaries. — L.C.
My additions to the weekly PNAS Tipsheet and This Week in PNAS