Award: OCE-1536672

The shapes and sizes of jellyfish vary greatly between different jellyfish species. Our goal was to evaluate how jellyfish shape, or morphology, can be used to predict the role of different species in the food web. We found that for all jellyfish species studied, the amount of food they consumed was directly related to the amount of water they process through their tentacles. However, the shape and number of tentacles and other capture surfaces was the most important determinant of the type of food they captured. We found that some species of jellyfish were more specialized at eating really small prey. These jellyfish are called rhizostomes and they do not have tentacles but have many very small digitata that line their complex mouths. Semeostome jellyfish, which generally have long tentacles and oral arms, are more specialized at capturing larger prey like adult copepods. Copepods are highly abundant zooplanktonic crustaceans that are found everywhere in the oceans and are very fast swimmers. However, we showed that because of their small size relative to the feeding current generated by jellyfish, the fast escape swimming does not significantly help copepods escape predation by jellyfish. Finally, we were able to demonstrate several ways that jellyfish move water to enhance the efficiency with which they are able to swim and transport prey to their tentacles and other capture surfaces. Most of the research done for this project was conducted by undergraduate college students. The students who worked on this project experienced the entire scientific process. They designed their experiments, carried out all of the work and analyzed the data. They were also integrally involved in communicating our findings with the scientific community by presenting their work at international conferences and writing papers that were published in peer-reviewed journals. Last Modified: 12/21/2020 Submitted by: John H Costello