Defense Date

8-10-2022

Document Type

Thesis

Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

Lauren Nadler, Ph.D

Second Advisor

Rosanna Milligan, Ph.D

Third Advisor

David Gilliam, Ph.D

Abstract

Corallivory is a common foraging strategy used by many fishes (e.g., parrotfish, butterflyfish) and invertebrates (e.g., Gastropoda, Asteroidea) on coral reefs and can be defined as the act of consuming coral mucus, tissue, and/or skeleton. While studies often focus on corallivorous fishes, we still have a limited understanding of corallivore foraging preferences even in these more well-studied taxa. To date, broad conclusions on corallivore selective foraging have been limited, as most studies focus on particular corals or corallivores in specific geographic locations. Using a meta-analytical approach, this project aims to study coral-corallivore interactions to identify any preferred characteristics that promote selective foraging. Using generalized linear models examining data from the published literature, we examined coral predation by butterflyfish (through bite rate using data on in situ measurements of fish behavior) and parrotfish (using percent predation on coral colonies through grazing scars). These analyses showed that butterflyfish forage selectively based on coral morphology, with a particular preference for branching morphology. Parrotfish were selective for the interaction of the factors coral family and coral size, measured as surface area in centimeters-squared. These analyses indicate that within complex ecosystems like coral reefs, a variety of factors are likely to affect coral-corallivore interactions and future scientific studies should delve into more diverse factors (e.g., fish behavior and territories, depth, coral abundance, presence/absence of predators, predated coral species, and predation on both established and transplanted corals) to draw broader conclusions about corallivore predation.

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