Project: The Ecology of Cloning

NSF Award Abstract: 

The recruitment of new individuals into marine communities is critical to determine community structure and yet, many basic parts of the life histories of marine invertebrates remain poorly described. Much of the understanding of the recruitment of marine invertebrates is based on theories centered on per-offspring investment, the dispersal of offspring in the ocean, and the survival of offspring during development. A major, largely neglected, area of research of the recruitment of marine invertebrates is the potential for asexual propagation of offspring during the embryonic and/or larval stages, also called cloning. Cloning is widely known to occur in diverse marine taxa, but the ecological consequences of this phenomenon are poorly understood. This project examines the ecology of cloning in Echinoderms, the taxon in which it is most widely reported. The work identifies the environmental triggers of cloning and tests the consequences of cloning at different stages in the life cycle. The work also trains undergraduate students, K-5 students and adult learners through research experiences, school presentations, and short courses in Maine and Virginia.

This project systematically evaluates inducers and consequences of cloning in multiple species from two temperate coastal habitats. Specifically, the work addresses two primary questions: 1) What are the environmental inducers of cloning and how likely are cloning events to occur in nature? 2) What are the consequences of cloning events for the recruitment of echinoderms into benthic communities? Current understanding of the initiation of cloning suggests that multiple stressors can induce cloning. Yet potential inducers have only rarely been investigated in a systematic fashion and never across multiple species within habitats or across habitats. The current project does both, assessing the potential for variation in biotic (algal food cues and predator cues) and abiotic (temperature, pH and salinity) parameters to induce cloning events in seven species of temperate echinoderms from two coastal areas (the Gulf of Maine and the Salish Sea). In addition to identifying inducers of cloning, very little is known about the fates of clones or the primary larvae that produce them, and therefore the ecological importance of this developmental phenomenon is a black box. As part of answering this second question, the investigators track the fates of clones that are generated at three different life stages (zygotic clones, early larval clones and late larval clones) to metamorphosis and beyond to determine the potential contribution of cloning to juvenile recruitment. By tracking the fates of clones to metamorphosis and in the weeks immediately following metamorphosis, when the vast majority of mortality occurs, they can estimate the degree to which cloning may be a viable developmental pathway for marine invertebrates.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.