IOS: RUI: Suction feeding in small organisms - outpacing the size limit

California State University-Fresno Foundation, Fresno CA

Investigators

Abstract

Bladderwort, an aquatic carnivorous plant, is among the fastest known predators, able to capture and ingest its prey in less than 1 millisecond. Bladderwort is also among the smallest suction feeders, sucking planktonic prey into millimeter-sized underwater traps. Bladderwort are interesting not just for their speed and small size, but because their feeding mode is also the most common found in fish, from larva to adult. Yet current understanding suggests that suction feeding is less suitable for small organisms such as fish larvae - small suction feeders experience water as viscous, which seriously limits suction speed and increases the energetic costs of suction. Fish larvae are known to have a low success rate at capturing prey and hence suffer high mortality from starvation, which in turn is a main factor limiting recruitment and adult fish population size.This study aims to identify the lower size limit of suction feeding. This study will lead not just to a better understanding of suction feeding in small organisms, but might also help to address the high mortality of larval fish. To study suction feeding in small organisms, students will conduct experiments on bladderwort to discover how suction feeders as small or even smaller than larval fish capture their prey. Students will build mathematical and robotic models to explore what limits capture success. The goal is to identify the morphological features and flow mechanisms that allow small organisms to suction feed. By combining data sets on bladderwort from Fresno State, students with data sets on larval fish and tadpoles from collaborating universities, this study will then compare the morphological and flow features of all three organisms to explore how far plants and animals have developed converging solutions. The research within this study will be conducted at a minority-serving institution. It will be integrated not only into undergraduate and Master's thesis research projects, but also into several undergraduate courses to enable roughly 2000 students per year to conduct authentic research as part of their course work.