51 Undergraduate Research Poster Session II (Posters)

Tuesday, 16 April 2024
1:30 PM - 5:30 PM
Grand Ballroom

FEEDING-INDUCED VARIATIONS IN ICHTHYOCARBONATE PRODUCTION AND COMPOSITION BY THE GULF TOADFISH

Paper number: 51-6
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

  • Sydney M. Cloutier Presenting Author
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Rachael M. Heuer
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Kathryn E. Hastings
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Jonathan Cordle
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Bret Marek
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Sarah Walls
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Jacob Belkin
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Martin Grosell
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL
  • Amanda M. Oehlert
    Rosenstiel School of Marine, Atmospheric, & Earth Sciences, University of Miami, Miami, FL

Abstract

Ichthyocarbonates are magnesium-rich calcium carbonate precipitates formed as part of the osmoregulation strategy of marine bony fish that allows them to remain hydrated by drinking seawater. Ichthyocarbonates are precipitated in the intestine, held together by organic mucus coatings, and excreted into the ocean continuously. Fish metabolic rate is thought to be an important control on ichthyocarbonate formation, however, the impact of feeding on ichthyocarbonate production rate and composition is poorly understood. Previous studies have shown that fasting does not prevent ichthyocarbonate production but have not examined how feeding state impacts production rate and composition—crucial factors expected to determine the role of ichthyocarbonates in oceanic carbon cycling. Here, we investigate how the feeding state of the Gulf toadfish (Opsanus beta) affects ichthyocarbonate production rate and size, crystallite morphology, mol%MgCO3, and phosphorus concentration under current ambient oceanic conditions. We collected ichthyocarbonates from fed and unfed Gulf toadfish, noting time elapsed since last meal. Samples obtained from the tank bottom daily and sampled directly from the intestinal lumen at the conclusion of the study. Wet weight and size of ichthyocarbonate were measured to evaluate changes in production rate or morphology with changes in feeding state. Preliminary wet weight results (milligrams of ichthyocarbonate/grams of total fish mass/day) indicate similar ichthyocarbonate production rate between fed (n = 18, M = 0.163 mg/g/day, ±SEM = 0.019 mg/g/day) and unfed (n = 18, M = 0.130 mg/g/day, ±SEM = 0.033 mg/g/day, p = 0.386) Gulf toadfish. Ongoing work includes Scanning Electron Microscopy to assess crystallite morphology and elemental analysis on an ICP-QQQ to determine concentrations of magnesium, calcium, and phosphorus to support comparisons between tank and intestinal samples. Results are anticipated to enhance understanding of controls on ichthyocarbonate composition, contributing to knowledge on their role in the global carbon cycle. This research highlights the underestimated significance of fish in the exchange of oceanic carbon, addressing critical knowledge gaps in ichthyocarbonate production rates.

Geological Society of America Abstracts with Programs. Vol. 56, No. 2

doi: 10.1130/abs/2024SE-398552

© Copyright 2024 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.