Estimating stable isotope turnover rates of epidermal mucus and dorsal muscle for an omnivorous fish using a diet-switch experiment

Authors: Winter, E.R., Nolan, E.T., Busst, G.M.A., Britton, J.R.

Journal: Hydrobiologia

Publication Date: 01/02/2019

Volume: 828

Issue: 1

Pages: 245-258

eISSN: 1573-5117

ISSN: 0018-8158

DOI: 10.1007/s10750-018-3816-4

Abstract:

Stable isotope (SI) analysis studies rely on knowledge of isotopic turnover rates and trophic-step discrimination factors. Epidermal mucus (‘mucus’) potentially provides an alternative SI ‘tissue’ to dorsal muscle that can be collected non-invasively and non-destructively. Here, a diet-switch experiment using the omnivorous fish Cyprinus carpio and plant- and fish-based formulated feeds compared SI data between mucus and muscle, including their isotopic discrimination factors and turnover rates (as functions of time T and mass G, at isotopic half-life (50) and equilibrium (95)). Mucus isotope data differed significantly and predictively from muscle data. The fastest δ¹³C turnover rate was for mucus in fish on the plant-based diet (T50: 17 days, T95: 74 days; G50: 1.08(BM), G95: 1.40(BM)). Muscle turnover rates were longer for the same fish (T50: 44 days, T95: 190 days; G50: 1.13(BM), G95: 1.68(BM)). Longer half-lives resulted in both tissues from the fish-based diet. δ¹³C discrimination factors varied by diet and tissue (plant-based: 3.11–3.28‰; fishmeal: 1.28–2.13‰). Mucus SI data did not differ between live and frozen fish. These results suggest that mucus SI half-lives provide comparable data to muscle, and can be used as a non-destructive alternative tissue in fish-based SI studies.

https://eprints.bournemouth.ac.uk/31498/

Source: Scopus