Thermal response of metabolic rates, feeding and growth in the corallivorous gastropod Drupella spp.

White, Ashlynn (2025) Thermal response of metabolic rates, feeding and growth in the corallivorous gastropod Drupella spp. MSc(R) thesis, University of Glasgow.

Abstract

The corallivorous gastropod genus Drupella is known for causing large amounts of damage across Indo-Pacific reefs, yet little is known about the genus’s thermal sensitivity, limiting our ability to predict how ocean warming will affect the impact of Drupella on reefs. Combining physiological and behavioural experimentation, the current study investigated the thermal response of metabolic rate, feeding, and growth of Drupella spp. Snails collected off the coast of Moorea, French Polynesia, were held in the laboratory at one of four temperature treatments: 28 °C (annual mean), 30 °C, 32 °C (annual maximum in 2021), and 34 °C (+2 °C warming scenario, SSP2-4.5). Using intermittent flow respirometry, metabolic rates were estimated under both acute ramping and prolonged thermal exposure. During acute thermal ramping, Drupella spp. acclimated at 28 °C and 34 °C were exposed to a rapid temperature increase from 29–38 °C. Temperature was increased in 1 °C increments over 30 minutes, followed by a 30-minute measurement period at each temperature. Metabolic rate increased consistently across the thermal range tested, indicating that Drupella spp. can tolerate high shortterm temperature changes, at least under well-oxygenated laboratory conditions. In prolonged exposure, both standard metabolic rate (SMR) and routine metabolic rate (RMR) increased between 28 and 32 °C for all acclimation durations. After three days of acclimation, SMR and RMR increased between 28–32 °C by 67.3% and 39.3% respectively, but then both declined by ~30% at 34 °C, indicating metabolic suppression beyond a thermal optimum. In contrast, snails acclimated for 19–23 days showed lower increases, with SMR and RMR rising between 28–32 °C by 26.9% and 19.1% respectively, and no suppression after 32 °C. These results demonstrate that Drupella spp. can thermally acclimate, particularly in RMR, which was significantly higher at 34 °C after longer-term acclimation compared to shorter-term. The same trend was observed in SMR, however this was not statistically significant. Unlike metabolic rate, feeding and growth showed no significant effects of temperature and did not increase with metabolic demands. Although this suggests that feeding and growth may not simply rise with warming; both remained unchanged compared to lower temperatures, indicating that Drupella spp. can sustain functional performance at elevated temperatures. The combined ability to withstand acute warming up to at least 38 °C, show signs of thermal acclimation, and maintain feeding and growth under elevated temperatures, suggests high thermal resilience in Drupella spp. Thermal resilience in the corallivorous snails raises concerns that corallivory may continue during periods of reef thermal stress, when corals themselves are less resilient to damage.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Subjects: S Agriculture > SF Animal culture
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Supervisor's Name: Bailey, Dr. David and Killen, Professor Shaun
• Date of Award: 2025
• Depositing User: Theses Team
• Unique ID: glathesis:2025-85665
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 12 Jan 2026 13:35
• Last Modified: 12 Jan 2026 13:41
• Thesis DOI: 10.5525/gla.thesis.85665
• URI: https://theses.gla.ac.uk/id/eprint/85665