DISSERTATION RESEARCH: Testing Alternative Hypotheses for the Goal of Orientation by Reef Fish Larvae throughout Development

Trustees Of Boston University, Boston

Investigators

Abstract

A central question of animal behavior and population ecology research is, how far do fish offspring disperse from their parents? This is because the dispersal of fish larvae connects distinct marine populations, thereby influencing the size and genetic diversity of those populations. In previous studies, marine ecologists have used two approaches to understand population connectivity: genetic methods that measure connectivity; and, oceanographic models that predict connectivity. There is, however, a large gap between the measured and predicted patterns of connectivity, which may be caused by the behavior of the fish larvae. Indeed, many reef fish larvae are outstanding swimmers that have the potential to influence their dispersal, but do they know where they are going? The objective of this research is to study the orientation abilities of fish larvae in the wild, throughout development and under a variety of environmental conditions, to determine whether understanding behavior can bridge the gap between observations and predictions of population connectivity. The completion of this research will enable improved predictions of population connectivity for other species, which will aid in the development of effective networks of marine reserves. The project will include a mentorship program for undergraduates in aquaculture and research, outreach to K-12 girls through the Science Club for Girls internship program and collaboration with local high school teachers. A significant gap in our understanding of marine ecology is the extent to which larval orientation behavior can influence the pattern of dispersal. This project will bridge this gap by investigating the ontogeny of larval orientation behavior using one tractable system: the neon goby, Elacatinus lori. The project has two main objectives: 1) to investigate changes in larval orientation abilities throughout development; and, 2) to test alternative hypotheses for the goal of larval orientation behavior, i.e., to determine what larvae are orienting toward. By deploying lab-reared larvae in a drifting in situ chamber, the researchers will test for an effect of age on the development of non-random orientation behavior, the proportion of larvae orienting and the precision of their orientation. The researchers will also manipulate the location of larval deployments to test and discriminate between alternative hypotheses for the goal of larval orientation. Ultimately, understanding the behavioral mechanisms of larval dispersal will increase our understanding of the causes of population connectivity and aid in the design of effective networks of marine reserves. Data will be archived at the National Oceanographic Data Center (NODC) or the NSF funded Knowledge Network for Biocomplexity (KNB).