The University of Southampton
University of Southampton Institutional Repository

The effect of growth rate on tissue-diet isotopic spacing in rapidly growing animals. An experimental study with Atlantic salmon (Salmo salar)

Trueman, C.N., McGill, R.A.R. and Guyard, P.H. (2005) The effect of growth rate on tissue-diet isotopic spacing in rapidly growing animals. An experimental study with Atlantic salmon (Salmo salar) Rapid Communications in Mass Spectrometry, 19, (22), pp. 3239-3247. (doi:10.1002/rcm.2199).

Record type: Article


The difference in isotopic composition between a consumer's tissues and that of its diet is a critical aspect of the use of stable isotope analyses in ecological and palaeoecological studies. In a controlled feeding experiment with the Atlantic salmon, Salmo salar, we demonstrate for the first time that the value of tissue-diet isotope spacing in nitrogen in a growing animal is not constant, but varies inversely with growth rate. The value of tissue-diet isotopic spacing in N reflects N use efficiency. Thus, in salmon, growth rate is accompanied by, or requires, increased N use efficiency. The total range in tissue-diet isotopic spacing in N seen in the experimental population of 25 fish was 1, approximately 50% of the total trophic shift. Mean equilibrium tissue-diet isotopic spacing (±standard deviation) in salmon averaged 2.3 (±0.3) and 0.0 (±0.3) for N in muscle and liver, respectively, and 2.1 (±0.1) and 1.6 (±0.3) for C in muscle and liver, respectively. Feeding with a mixed dietary source (wheat and fish-meal origin) resulted in tissue-diet isotopic fractionation in both C and N due to the differential digestibility of food components with distinct isotopic composition. The rate of change in isotopic composition of S. salar tissues was dominated by growth, but the estimated contribution of metabolic turnover to change in tissue N was relatively high for an ectothermic animal at ca. 20-40%. The estimated half-life for metabolic turnover of the tissue N pool was ca. 4 months in both muscle and liver tissue. This is the first study to demonstrate a direct relationship between tissue-diet isotopic spacing in N and growth rate and adds to the growing list of factors known to influence the level of isotopic separation between a consumer's tissue and that of its diet.

Full text not available from this repository.

More information

Published date: 2005


Local EPrints ID: 37991
ISSN: 0951-4198
PURE UUID: 3e7a54f2-05af-46e8-91c0-37ba64cb1a90

Catalogue record

Date deposited: 26 May 2006
Last modified: 17 Jul 2017 15:40

Export record



Author: C.N. Trueman
Author: R.A.R. McGill
Author: P.H. Guyard

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.