Graduation Year

2026

Document Type

Dissertation

Degree

Ph.D.

Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Integrative Biology

Major Professor

Andrew Kramer, Ph.D.

Committee Member

Cameron Ainsworth, Ph.D.

Committee Member

Sean Doody, Ph.D.

Committee Member

John Parkinson, Ph.D.

Committee Member

Kevin Thompson, Ph.D.

Keywords

apparent competition, food web, habitat suitability, prey preference

Abstract

Indo-Pacific lionfish (Pterois volitans and P. miles) and regal demoiselle(Neopomacentrus cyanomos) are reef-associated fishes that have invaded the Western Atlantic Ocean, Gulf of Mexico, Bahamas, and Greater Caribbean. While invasive lionfish are established mesopredators with documented impacts on native reef communities, regal demoiselle are at an earlier stage of invasion, and their ecological risks are unclear. Because lionfish consume regal demoiselle in their invaded range, interactions between these species, particularly predation, may influence regal demoiselle invasion success. This dissertation assessed the invasion risk of regal demoiselle, focusing on predator-prey interactions among these species. The objectives were to 1) identify areas where both taxa are likely to co-occur and the associated environmental characteristics, 2) determine whether lionfish prefer regal demoiselle or native prey, and 3) predict the impact of lionfish predation on regal demoiselle compensation at an ecosystem level. We hypothesized that both taxa share similar geographic and habitat preferences, lionfish exhibit no preference based on prey geographic origin, and lionfish limit regal demoiselle compensation through direct predation. We assessed these hypotheses using species distribution modelling, behavioral predator-prey experiments, and food web modelling, respectively. We found that 1) both taxa have high potential to co-occur across invaded areas, 2) lionfish lacked strong prey preference, but may more frequently consume invasive regal demoiselle over native prey, and 3) lionfish predation is likely to limit invasive regal demoiselle compensation, but this outcome is highly dependent on how much lionfish consume regal demoiselle and on environmental conditions. Overall, our findings suggest lionfish may inhibit regal demoiselle invasion success, though the possibility of facilitation cannot be excluded. Future research should further examine both direct and indirect interactions to better evaluate regal demoiselle invasion risk.

Download

Share

COinS