About This Project

The Parana River is one of the world's largest rivers and provides water for a large portion of southern Brazil, and is heavily impacted by hydroelectric dams. This study seeks to examine the dynamics of this ecosystem utilizing molecular ecology. We will collect fecal material and sequence the gut microbiome of 6 species of fishes in order to compare their gut microbiomes. We hope that through this study we can determine how the gut microbiome varies on a spatial and phylogenetic scale.

Ask the Scientists

What is the context of this research?

Gut microbial ecology is a very new method for studying ecosystem processes. It has recently been applied to everything from human health, to insect physiology. It has not, however, been applied widely to aquatic ecosystems. This method could be widely applicable to important ecological questions such as ecosystem carbon flow, and aquatic organism nutrition. This pilot study will examine the potential for the fish gut microbiome to mediate ecosystem carbon flow through detritivorous fishes. In order for us to do that though we need a broad understanding of how gut microbes vary on phylogenetic, spatial, and temporal scales in fishes. This project will attempt to understand this variation by sampling gut microbes from six species of fish on the Upper Paraná River Floodplain in south Brazil.

What is the significance of this project?

Recent research on the gut microbiome in mammals has expanded our understanding of the role that the microbiome plays in nutrition, health and behavior. Advances in the study of human-microbe symbioses indicate similar importance in other vertebrate taxa. Limited research has been conducted on natural populations. This study will test for environmental and phylogenetic effects on gut microbial diversity in fishes of a Neotropical floodplain. In doing so, this study will contribute to greater understanding of the ecology of tropical ecosystems and provide context for conservation. There is great potential in this study to contribute to our knowledge of human health as well. Gut microbiomes have been shown to be remarkably similar between fish and other vertebrates.

What are the goals of the project?

This project seeks to test the following hypotheses and to publish the results in a peer reviewed journal:

1. Gut microbiomes in detritivorous fishes will differ among species from the same habitat and will differ within species collected from different habitats.

2. For the interaction effect in Hypothesis 1, species identity will play a stronger role in shaping the gut microbiome than local habitat.

3. Phylogenetic relatedness will correlate positively with gut microbiome similarity.

4. For the commercially important artisanal fisheries species Prochilodus lineatus, gut microbiome diversity will positively correlate with body condition (i.e. body mass – length relationship)